So I have posted a few times on here with all my problems. The main issue was that I had no place to work on it. I now have a little heated shop with all my tools so now I can get some work done. I started looking at it today and have many questions. Ill start with the easy stuff first.

1. I have oil leaking down the back of the engine, it looks like its from the valve covers. I tried to capture it with a few pics. Can/should I just reseal the covers or it common to leak like that or is it leaking from someplace else?

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4239&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4242&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4248&g2_serialNumber=3

2. My trans is having issues. I think its a wiring issue, but first, is the wire in the pic supposed to be like that??? Also, is that the speed sensor Harness?? ( I know, I unplugged it to clean it since the speedo doesnt move.

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4254&g2_serialNumber=3

3. The engine was supposedly rebuilt. There is this massive bunch of wires here. Anyone have a schematic on our trucks? Mine is a 93 3500 dually 4wd with ZERO options.

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4255&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4260&g2_serialNumber=3

4. Next stop on this tour is the oily mess on the turbo. Its caked in oil and there is oil inside. Its all coming from the CDR valve. There is a large buildup of oil at the base of the CDR valve and valve cover. Is this part bad or is this normal. Also what is that object on the left?

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4261&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4266&g2_serialNumber=3

5. Our final stop for todays tour is the arm that attaches to that cannister deal. Im not sure if this is supposed to move. I would think it should but as you can see in the pic, there looks to be an issue. Is that an issue? what can I do to fix it??

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4267&g2_serialNumber=3



I really appreciate your helps. I have done so much reading and searching on here its painfull. There is so much here but sometimes I need to ask questions my way to better understand it.

Thanks yall

The valve covers leaking is common but can be caused by the cdr valve not working properly. If the cdr is'nt working right the crankcase will pressurize and blow oil out where ever it can. This may be why the turbo has oily gunk in it also. The canister on the turbo is a mechanical boost control. It's the factory version of a "turbomaster" The rod that comes out of it should move but with some resistance due to the spring in the canister.
The wiring on the firewall needs to be put back in the plastic shething to prevent chaffing the insulation on the wires that could cause shorts. Same goes for the wiring by the transmission. I am not familiar with the wiring for the transmission on a manual transmission. The wiring at the rear should be the speed sensor.
I don't have the 93 factory manual. I have :91,95,and 97. The 91 is very similar because it has the mechanical fuel injection pump. The 95 and 97 have the electronic pumps and are a whole different ball game. What is your question or problem with the wiring? I am unaware of your previous problems.
You may want to update your signature with transmission type[manual or auto] and mileage on truck. It will help with answering questions.

on first look the pic of the oil on the fenderwell are you loosing powersteering fluid? this is where a leaking hydroboost drops powersteering fluid.
but with the other pictures it suggests that you have a lot of blowby, especially with the pic of the turbo and the oil being fed by the cdr valve.
you need to do a blowby test.

the pic of the canister that attaches to the turbo is for preventing the opening of the turbo bypass(popoff) valve. it is not moved easily.

the pic of the lever on the turbo is of the popoff valve lever it rotates clockwise and is hard to turn due to the spring pressure in the canister. that being said it should turn if it does not you risk blowing the engine due to over boost.

the lever as i said rotates clockwise looking at the picture the lever pulls up.

i do have a full gm service manual and a complete wiring diagram set (aftermarket i think) the wiring diagram is available online for only about 16.00 it is emailed to you in pdf format. however with that being said what portion of the wiring are you interested in.
wes pierce

Wow, ur engine ALMOST looks like mine, OIL caking everthing, sucks to work on, yeah i have that problem!! But the wires, wow, looks like a headache....

The valve covers leaking is common but can be caused by the cdr valve not working properly. If the cdr is'nt working right the crankcase will pressurize and blow oil out where ever it can. This may be why the turbo has oily gunk in it also. The canister on the turbo is a mechanical boost control. It's the factory version of a "turbomaster" The rod that comes out of it should move but with some resistance due to the spring in the canister.
The wiring on the firewall needs to be put back in the plastic shething to prevent chaffing the insulation on the wires that could cause shorts. Same goes for the wiring by the transmission. I am not familiar with the wiring for the transmission on a manual transmission. The wiring at the rear should be the speed sensor.
I don't have the 93 factory manual. I have :91,95,and 97. The 91 is very similar because it has the mechanical fuel injection pump. The 95 and 97 have the electronic pumps and are a whole different ball game. What is your question or problem with the wiring? I am unaware of your previous problems.
You may want to update your signature with transmission type[manual or auto] and mileage on truck. It will help with answering questions.

So if I replace the CDR with a new one, Would I need to replace the gaskets on the valve covers or will they seal fine with since there will be no more pressure?

Yeah the wiring, I know, its reduculous. I got the truck fairly cheap and overall it works great but I would like to tidy some things up and fix the issues. A bunch of my issues are trans related, My speedometer doesnt work. it jumps around every once in awhile so I bebelive there is a short somewhere. But the other issue which im hoping is related to the speed sensor issue is the trans will downshift out of OD for more power if it needs it but then it will not return to OD until I turn the truck off and restart it. It will do the same for 2-3 as well depending on my speed. I have an auto trans, the 4L80E and mileage is unknown because of the malfunctiong speed sensor. the odo reads 120k though so its got at least that much.

on first look the pic of the oil on the fenderwell are you loosing powersteering fluid? this is where a leaking hydroboost drops powersteering fluid.
but with the other pictures it suggests that you have a lot of blowby, especially with the pic of the turbo and the oil being fed by the cdr valve.
you need to do a blowby test.

the pic of the canister that attaches to the turbo is for preventing the opening of the turbo bypass(popoff) valve. it is not moved easily.

the pic of the lever on the turbo is of the popoff valve lever it rotates clockwise and is hard to turn due to the spring pressure in the canister. that being said it should turn if it does not you risk blowing the engine due to over boost.

the lever as i said rotates clockwise looking at the picture the lever pulls up.

i do have a full gm service manual and a complete wiring diagram set (aftermarket i think) the wiring diagram is available online for only about 16.00 it is emailed to you in pdf format. however with that being said what portion of the wiring are you interested in.
wes pierce

Good call on the powersteering fluid, the end of last year the belt broke and tore into the power steering resivor but 90% of that is engine oil for sure.

So for the turbo lever, is that arm/plate that is twisted, is that normal? I would think it should be nice and flush with the housing. It looks bent. Is replacing the turbo the only way of fixing this? Ill try moving it one more time but as you know, there isnt much room in that area.

Reason I need a wiring diagram is that whoever put the truck back together used divverent coler wores to extend certain wires and its confusing as all heck to try to follow them. The truck has a few shorts and strange issues so I just would like to be able to trace the wires down.

Wow, ur engine ALMOST looks like mine, OIL caking everthing, sucks to work on, yeah i have that problem!! But the wires, wow, looks like a headache....

So im not alone!!!! I see so many pics of peoples engine bays on here and they are always clean or close to it, lol. Mine was a work truck its whole life and has never been cleaned or cared for like a personal truck.



Thanks for all the comments so far. I need more though!!! I am going to go work on it a bit tonight and snap a few more pics of things as well.

Does this look like a decent shopping list from ssdiesel supply??

Here it is with a better attachemnt. It didnt work like I thought it would originally.

I would start with a cdr at first. Then see what else you need.

some guys say they can get a cdr at a local parts place for $40

The wiring looks just like it should, there is just no loom around it.

I do have an uncut engine/tranny harness i just pulled off my 93, i was saving it to go with the tranny controller, but now it looks like guys dont need that tranny controller anymore. Someone figured out how to use a mech pump with the stock computer. Anyhow its sitting on my garage floor.

OH ya.....im not real positve that the cdr can cake the outside of the turbo like that.....u sure your oil feed line isnt leaking??

I would start with a cdr at first. Then see what else you need.

some guys say they can get a cdr at a local parts place for $40

The wiring looks just like it should, there is just no loom around it.

I do have an uncut engine/tranny harness i just pulled off my 93, i was saving it to go with the tranny controller, but now it looks like guys dont need that tranny controller anymore. Someone figured out how to use a mech pump with the stock computer. Anyhow its sitting on my garage floor.

OH ya.....im not real positve that the cdr can cake the outside of the turbo like that.....u sure your oil feed line isnt leaking??

Cool, I think I am going to place that order minus a couple things. It will be nice to have a box of parts come in, swap them all out then see where im at.

How much do you want for that harness?

I just saw your sig, do you still have the cab of your truck? what condition is it in?

Ill look to make surethe oil line isnt leaking, I remember it being pretty clean right around there.

Thanks for the help!

Also, is it ok to skip the CDR and just vent the crank to atmoshphere? I know that is a common mod on the 7.3 which I have done with no issues. It keeps the oil out of the turbo and intercooler.

when i put my engine together no valve cover gaskets were used. i used only black rtv NO leaks in 14 months.
the lever is normal that is exacly how mine looks look at my garage i will post a pic later.
the oil on the turbo can get that bad just from a bad cdr and to much crankcase pressure from blowby. just needs a good perodic cleaning.
i found the pic of the turbo on my 93 i modified the drain hose got tired of the oilleak by the rubber hose.

what these guys said plus take the big bolt out [3rd pic down]of the oil filter housing and replace the o rings,same with the broken glow plug,take it out and replace it or all of them,the can in the 3rd pic up from bottom,take it off ,cut it in half,take out the spring,thread the rod,put in a bigger spring,put nut on rod, got you a homemade turbo master for about $5 ,better put yourself a boost gauge in,or set it with a oil pressure or any gauge you got laying around,search my posts i got pics on here somewhere of mine,its a 93 also,also go ahead and hook up a high idle while your in there,toggle switch and some wire is all you need for that,hot wire to the toggle then to the green wire on the right front of your pump

Ok well firstly, thanks for all the help today. I was able to get a little more done today in the way of inspecting things and such. In reguards to the wastegate arm on the exhaust housing, im an idiot, I was trying to turn it the wrong way, ( thanks for the pointers of which way the arm operates ) it turns and works well so that possible disaster is resolved. I removed the passenger side wheel liner, it wasnt as hard as I thought but im not sure Ill be able to get it back on, LOL. It is kinda rusty around the bolt holes and I had to grind a few off.

1. Here is the backside of the compressor housing.

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4272&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4278&g2_serialNumber=3

2. More detail on the CDR.........

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4273&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4304&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4305&g2_serialNumber=3

3. I pulled 2 of the glowplugs since I plan to replace them all. My 7.3 hasnt had new ones yet so im not sure what is normal when you pull a used one out. The one pictured below is from the passenger side and closest to the firewall, I beleive that cyl #8?

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4285&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4290&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4291&g2_serialNumber=3

4. What the heck happned to my DP??!! Looks like it got ran over! Opinions?

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4296&g2_serialNumber=3

5. A little help here............

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4297&g2_serialNumber=3

6. The + cable that comes off the alt is tiny, is that stock? it looks like it to me, is there any benifit to upgrading it to a 4 gauge?

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4306&g2_serialNumber=3

7. There is this little conector that was not plugged into anything and looking at it I wonder why! I cant find where it is supposed to go, any ideas?

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4284&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4309&g2_serialNumber=2

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4279&g2_serialNumber=3


Ok well thats it for tonight. I apreciate all your help so far and all that I can get. I hope the pics help, I know it would if I were the one that was trying to help!

Thanks!!!!

what these guys said plus take the big bolt out [3rd pic down]of the oil filter housing and replace the o rings,same with the broken glow plug,take it out and replace it or all of them,the can in the 3rd pic up from bottom,take it off ,cut it in half,take out the spring,thread the rod,put in a bigger spring,put nut on rod, got you a homemade turbo master for about $5 ,better put yourself a boost gauge in,or set it with a oil pressure or any gauge you got laying around,search my posts i got pics on here somewhere of mine,its a 93 also,also go ahead and hook up a high idle while your in there,toggle switch and some wire is all you need for that,hot wire to the toggle then to the green wire on the right front of your pump


Thanks for the help, I will def replace that oring(s). Any idea what a part # is for them?

I will check out your pics, the power, although low is plenty for what the truck is used for. Plus it will keep the employees in check, haha. I will def hook up the high idle, it will work better than my foot..............

I'd replace the CDR not vent to atmosphere as it helps with leaks and dosen't really cost you anything in the power area. I've got a '93 as well, i did the wastegate mod to get a little more boost as the '93 only runs about 4-5psi from the factory. Clean the valve cover good before you install the new CDR, if you decide to R&R the valve covers and re-seal them dont' waste your $ on gaskets. They will leak, RTV or good sealer is your friend there. In order to R&R the valve covers, you'll have to unhook the injector lines from the injectors, be very carefull not to get any junk in those. Good luck

Don

CDR definitely bad. Should be <$50 at Napa.

You asked if it is ok to vent it to the air, it looks like you are doing it now.

The GP looks bad also with the carbon build up.

The DP is like that from the factory. Most of us changed it with a decent exhaust system 3" DP to 4" exhaust no cat. Look at people's signature for idea.

I'd replace the CDR not vent to atmosphere as it helps with leaks and dosen't really cost you anything in the power area. I've got a '93 as well, i did the wastegate mod to get a little more boost as the '93 only runs about 4-5psi from the factory. Clean the valve cover good before you install the new CDR, if you decide to R&R the valve covers and re-seal them dont' waste your $ on gaskets. They will leak, RTV or good sealer is your friend there. In order to R&R the valve covers, you'll have to unhook the injector lines from the injectors, be very carefull not to get any junk in those. Good luck

Don

I think I will just leave the valve covers the way they are now then, thanks for the help.

CDR definitely bad. Should be <$50 at Napa.

You asked if it is ok to vent it to the air, it looks like you are doing it now.

The GP looks bad also with the carbon build up.

The DP is like that from the factory. Most of us changed it with a decent exhaust system 3" DP to 4" exhaust no cat. Look at people's signature for idea.


I just took the CDR off and took those pics. It looked pretty obvious that its toast so I just took it out anyway and figured id take a few pics.

Im going to get a new CDR today at Napa, only $45 so thats good.

I bet all the GPs look like that too so ill just go ahead and replace them all.

Thanks for the help buddy

I have the oil all on my turbo just like yours. The only place where i dont have oil is where i want it, on my rotted gp's. I can only get one gp out (because its been caked in oil for yeears...) NICE JOB with the pics, they help explain a lot!!

Does anyone know where to get a new transmission pan at? Mine is leaking through a rust bubble. I cant seem to find any autoparts store that has the pan and I dont need one of the fancy $200+ aluminum pans either. Any help on that would be appreciated!!

I may just weld in a metal patch but Id rather try to price out a new one first at least.

I would just weld the pan, a GM dealer may be the only place to get an OE pan these days and most are going to be kind of expensive, just throw a patch on it and call it good.

when i replaced the pan on my 700R4 i think it was $100 at the dealership...i can price it for you what the shop cost is and you can take that price to them ;)

i will try to find the part # on orings when my boy brings my truck back,tomarrow :(,or if your close to a gm dealer give them your vin,i know they are not the same as the 94/95,as for the hole in your tranny pan,if its just in one place id just put a drain plug there depending where the whole is,may be no room for one,thats what i did on a ford i had,think it had 3-4 drain plugs in it by the time i got rid of it,but its cheap and easy ;)

Thanks I would appreciate it! I found a place that has a pan for $85 with the gasket so Ill probably just do that.

Ok so were getting somewhere! I replaced the 3 glowplugs that were not hooked up. Ill get around to the others soon. I replaced them with the 60Gs since thats what was in stock at Napa. No one around here has the CDR in stock so im stuck having to order it, no biggie. The truck BARELY smokes during startup!! It used to smoke really bad and for quite some time before it would stop.

I started up the truck which can be watched below. I started to crank it before the video, the video is the 3rd time trying to start it. I have to pump the go pedal as I start it or it will never turn over. is that the sign of a bad lift pump? and sorry for the wobbles, it gets a little bouncy sitting the camera on the core support! Also, the background noise is my heater

http://www.youtube.com/watch?v=zlFJoAqmnLk


There is a wierd tick in the back of the engine, Its the pass side closest to the firewall. Just has a different sound right there but no where else on the engine. The camera doesnt pick up the sound well but its pretty prevelant when when looking at the engine through the wheel well.

http://www.youtube.com/watch?v=iI7-e_9Iis0


The video doesnt show all the smoke coimg out of the hole but you can see its not much. that is normal for these engines right?

http://www.youtube.com/watch?v=0n22tbMeWKs


Now on to the few pics.

I found a broken ground strap, the following is what I did to repair it.

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4316&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4317&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4318&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4325&g2_serialNumber=3

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4326&g2_serialNumber=3


Then I had to try and use the existing DP clamp since I didnt want to spend $40 on a new one. The problem was, as you tighten or losen the nut, the "T" end rotates out of place and it doent allow you to tighten or loosen the clamp. I had sprayed with some PB Blaster and rand the nut up and down threads a few times before putting it back on which freed up the threads and allowed the nut to move freely. To tighten, I used a pair of needle nose vice grips to clamp the T into its seat. Just make sure you dont do what I did the first time and thats to have the vice grips clamped in the middle as shown in the pic.

http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4327&g2_serialNumber=3


Thats is for now. I would still like a bunch of answers on things like the stray plug, the relays and terminal block IDs and if the + alt wire is supposed to be so small.

Thanks!!

man I wish more people used pictures to give us a better idea on the issues concerned with there 6.5 Kudos to you and great job.

A few things to touch base on here:

The mess of wires is a must to take care of as stated before. Loose/ free floating wires can spell disaster for not only the engine, but also parts. If needed, wrap it all with tie wraps or electrical tape. I replaced my crossover cable from the small pathethetic one to a 4/0 cable. The anchors where bad so It slipped back and forth alot. Luckily I was under the hood practically everyday cleaning and modifying to notice that the cable was coming into contact with the fan. Caught it just in time as it had made a decent gash into the jacketing. But now its all good:D Nothin a few EMT straps can't fix

There have been a few threads reguarding venting the CDR to the atmosphere. Basically it all came down to alot of irritation and aggrivation reguarding group X saying its a bad idea and causes damage while Group Y said no it doesnt as they have done it and (so many miles) later everything is still fine.
Normal blow-by is low, so vacuum must be regulated such that air is not drawn into the engine thru various seals - crankshaft, valve-stem, oil filler and dipstick tubes. The crankshaft seals assume greatest importance because of location down low in road draft area.


The CDR, Crankcase Depression Regulator, is designed to function with low-level vacuum. The tuna-can size is to accomodate the large silicone rubber\synthetic diaphragm. Vacuum on the diaphragm actuates the valve against a low-pressure spring, calibrated for turbo or non-turbo applications, which also functions to ensure that the valve opens as vacuum decreases.


Fully open at idle, it will begin to close as power demand and vacuum increases, regulating the 'depression' in the crankcase such that excessive oil is not drawn out of the engine, and blow-by pressure in the crankcase does not increase.


It is not a one-way valve, but closure is toward the vacuum source. It opens under crancase 'back-fire' conditions, and would become a 'no-way' valve if the diaphragm ruptured, allowing excessive vacuum to develop in the crankcase.


Because blow-by vapor is drawn into the turbo inlet, oil will accumulate in the inlet area, but is not cause for concern unless the quantity approaches a quart a month. Excess vapor from worn piston rings can cause engine surging, as vapor is drawn into cylinder and ignited along with injected fuel, which is a light oil.


Non-Diesel oils vaporize more easily due to higher pressures and temperatures encountered in Diesel service, particularly those in the turbocharger housing.



Oil on the glow plugs is bad as this means oil is seaping into the threads. As for the carbon buildup, your fine. Diesels generate alot of carbon due to there nature. Next time you wash your truck, take a sponge or something to your ehaust pipe end. Drive around for a few minutes and check back. Covered in soot again.

Your downpipe is comes factory equipped with dents/ bangs, and generally looks like GM ran it over then gave it to a chimp with a hammer. Replace it with a 3" mandrel bent one. You WILL NOT regret doing so. I'm going to be doing a general thread reguarding downpipes as soon as mine comes in on Monday ish. Check back here and you shall learn.

Those relays and grounding block are aftermarket. Seems the previous owner did quite a bit of tinkering with the electrical. This may also explain your not working speedometer.

All in all you have alot of work to do but just try and have fun with it. Spend some time just going over everything like you have been and cleaning her up. Good luck

It seems like it idles really low plus it sounds like your high idle isn't working. That tick on the left side seems like an exhaust leak to me, I noticed in one of the earlier pictures it looked like you were missing one of the 3 bolts in the bottom of the exhaust manifold, is it the same side, that might be your culprit. And as blue said, good job on the pictures, that this process alot easier!

man I wish more people used pictures to give us a better idea on the issues concerned with there 6.5 Kudos to you and great job.

A few things to touch base on here:

The mess of wires is a must to take care of as stated before. Loose/ free floating wires can spell disaster for not only the engine, but also parts. If needed, wrap it all with tie wraps or electrical tape. I replaced my crossover cable from the small pathethetic one to a 4/0 cable. The anchors where bad so It slipped back and forth alot. Luckily I was under the hood practically everyday cleaning and modifying to notice that the cable was coming into contact with the fan. Caught it just in time as it had made a decent gash into the jacketing. But now its all good:D Nothin a few EMT straps can't fix

There have been a few threads reguarding venting the CDR to the atmosphere. Basically it all came down to alot of irritation and aggrivation reguarding group X saying its a bad idea and causes damage while Group Y said no it doesnt as they have done it and (so many miles) later everything is still fine.
Normal blow-by is low, so vacuum must be regulated such that air is not drawn into the engine thru various seals - crankshaft, valve-stem, oil filler and dipstick tubes. The crankshaft seals assume greatest importance because of location down low in road draft area.


The CDR, Crankcase Depression Regulator, is designed to function with low-level vacuum. The tuna-can size is to accomodate the large silicone rubber\synthetic diaphragm. Vacuum on the diaphragm actuates the valve against a low-pressure spring, calibrated for turbo or non-turbo applications, which also functions to ensure that the valve opens as vacuum decreases.


Fully open at idle, it will begin to close as power demand and vacuum increases, regulating the 'depression' in the crankcase such that excessive oil is not drawn out of the engine, and blow-by pressure in the crankcase does not increase.


It is not a one-way valve, but closure is toward the vacuum source. It opens under crancase 'back-fire' conditions, and would become a 'no-way' valve if the diaphragm ruptured, allowing excessive vacuum to develop in the crankcase.


Because blow-by vapor is drawn into the turbo inlet, oil will accumulate in the inlet area, but is not cause for concern unless the quantity approaches a quart a month. Excess vapor from worn piston rings can cause engine surging, as vapor is drawn into cylinder and ignited along with injected fuel, which is a light oil.


Non-Diesel oils vaporize more easily due to higher pressures and temperatures encountered in Diesel service, particularly those in the turbocharger housing.

Thank you thank you for that explanation! I know nothing about these diesels and compared to my 7.3, well they are completely different from one another!

I will def make sure I put the new CDR in. In my uneducated postion about these engines, I bet it would be fine to run to atmoshpere but for a $50 part, I might as well just put a new one in.



Oil on the glow plugs is bad as this means oil is seaping into the threads.

So what your saying is the oil that is dripping down the outside of the block is seeping INTO the threads or that there is oil in the CYL and seeping out? if its seeping, thats no biggie, once the block is cleaned, that should ne a non issue.

As for the carbon buildup, your fine. Diesels generate alot of carbon due to there nature. Next time you wash your truck, take a sponge or something to your ehaust pipe end. Drive around for a few minutes and check back. Covered in soot again.

Im pretty familiar with soot, my chipped 7.3 does its share and then some of polluting the air :D. In fact im kind of wierded out that there is no black smoke from the 6.5. or at least none that I can see.


Your downpipe is comes factory equipped with dents/ bangs, and generally looks like GM ran it over then gave it to a chimp with a hammer. Replace it with a 3" mandrel bent one. You WILL NOT regret doing so. I'm going to be doing a general thread reguarding downpipes as soon as mine comes in on Monday ish. Check back here and you shall learn.

Subscribed.............

Those relays and grounding block are aftermarket. Seems the previous owner did quite a bit of tinkering with the electrical. This may also explain your not working speedometer.

Its been a company and work truck its whole life. It has a plow, dumping flatbed, and it has had slaters and fert tanks on it since it was born. It hasnt had the easiest life but it was fleet maintained which for the company that owned it, is a good thing. Speedo is still a mistery. that will be tackled next week.

All in all you have alot of work to do but just try and have fun with it. Spend some time just going over everything like you have been and cleaning her up. Good luck


You may think I have alot of work to do but in about 3 weeks I am going to need the truck 5 days a week so I dont have much time and the worst part, money. Winter here has sucked for the most part this year leaving me pretty broke. Hopefully next winter I will be able to really dig into it. I mainly just need the motor and trans to work, everything else is OK or at least good enough for the season. Im going to tackle the rust next year.

Thanks again for your great post!!

It seems like it idles really low plus it sounds like your high idle isn't working. That tick on the left side seems like an exhaust leak to me, I noticed in one of the earlier pictures it looked like you were missing one of the 3 bolts in the bottom of the exhaust manifold, is it the same side, that might be your culprit. And as blue said, good job on the pictures, that this process alot easier!

You know, now thatI think about it, I did see some air bubbles coming out of the GP hole where the sound was and I just now realized that I forgot to turn that a tad bit more. THANKS!!!!!!! I have been a little worried that there is some internal damage.

As for the low idle, I have a 115,000 BTU torpedo heater right in front of the truck blowing into the engine bay. Im sure the coolant is warm enough that its not triggering the high idle. I could be totally wrong on that though.

the missing bolt is on the drivers side. its one of the flange bolts that was never tightened and was just rattling around. I took it out because it was annoying me. I need to toss another in.

yes the powerstroke and 6.5 are like comparing nite and day aside from both being V8 TD's

as for the GP there could be a chance that the compression from inside the cylinder was forcing some of the oil through the threads. The easiest way to test this is clean that oil off the threads, pop it back in nice and snug, and check on it after so many miles. Say 100 or something of that nature. I could just be not tightened enough.

The 6.5 isn't a smoker at all. A friend of mine has a 24V cummins that smokes real nice and another friends grandpa has a chipped 7.3 that billows smoke. Smoke from a 6.5 is BAD. A little puff here and there is normal, but to much means high EGT's. And High EGT's can spell disaster for any truck, ESPECIALLY THE 6.5

Hey no problem. We are all hear to help. Theres alot to learn here about the 6.5 and once you get a handle on it there are alot of possibilties, options, and things to be done. Best get on that truck then :D Whats that saying? "So much and so little time?"

Haha yeah its funny because as I was growing up my Dad always had these chevy trucks with the 6.2 and 6.5 and he was never a fan of them and because of that, I wasnt either. The only reason he had them was that was about all you can get as a sweeper truck. But then I bought this truck for my company and its paid off, its the only car/truck I have had that I truely own and for whatever reason I love this truck! Im not a huge chevy guy but 6.5 is an under dog and I always root for the under dog! This truck has some good character to it and a few friends say to dump the truck but I dont want too, lol. I just bought another truck but its another ford with the 7.3. Anyway, im babbling

In your firewall wiring/power distribution block pic, thats the factory setup for that year.
#1 is fuel pump fuse.
#2 is fuel pump relay
I dont know what #3 relay is. Does it have dual tanks or an electric fan? Maybe 4wd. I'd try to trace the wiring from #3 relay.

Your loose wire prolly should go to A/C press switch on the accumulator if you had one.

Did the glowplug fix your leak/tick? When I put new heads on my 93, I guess one of the glow plug holes had a burr, it sounded like I had an exhaust leak(of course it was the one behind the downpipe). It took me awhile to find it(I thought it was a manilfold gasket at first), I removed the GP and swapped in another(snugged it a little extra for good measure), fixed the leak thankfully.

Awesome! thanks for the relay help! I do have 4WD, no electric fan though. Ill try switching in/out of 4WD and test it out.

Good deal about the stray wire/plug. I hope that is what its for, because then I wont have to find where its supposed to be.

I didnt tighten the GP yet. It wasnt until the post this evening that I realized that it was most likely the GP leaking. Ill know on monday when I get to work on it next.

Nice truck in that avatar BTW, and thanks for the help!

I took this vid after the truck had been running for about 5 mins. I have never seen this before, any thoughts?

http://www.youtube.com/watch?v=DfTtpxqQ6Ls

I have a few more updates as well but ill get to those later

From that video it looks like you have one or two bad injectors, that is why the white smoke is intermittent.

Should all the injectors be replaced at the same time? How do you test for bad injectors?

Ok, back with some updates.

Here is the video of a cold start. I just bought a new pift pump, LP relay, and OP sensor since it seems like from what I have read that if its hard to start, its likely the lift pump. I have read that there are ways to test it operation but also read they have a limited lifetime. mine looks to be orginal byt the amount of rust on the LP fittings. I am going to test it before I put any new parts on but at least I have the new parts ready just in case. Video-
http://www.youtube.com/watch?v=c3RdC-UKNkM

Here is my next painful project.
Its soaked in PB Blaster right now. Any other tips on removing it?
http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4337&g2_serialNumber=3
Is this the return line as noted in the photo?
http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4339&g2_serialNumber=3

Here is a pic of that lovely trans pan leack
http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4344&g2_serialNumber=3
http://www.mobileaudioguy.com/photos/main.php?g2_view=core.DownloadItem&g2_itemId=4345&g2_serialNumber=3

Tomorrow a bunch of new parts come in so lookout for a long post tomorrow night, LOL.

You need injectors, glow plugs or both. How many miles on the engine?

it was rebuilt by the previous owners but im not sure the maintenance history. It was a company truck in a large fleet of well maintained vehicles. When the speedo stopped working there were 118,000 miles. They got rid of it shortly after that stopped working. The injectors. by the looks of them, were not replaced at the time of the rebuild.

Yeah, something is up with the intermittent puffing... I need new plugs and injectors also, mine have ALMOST 200k on them... Sad but true.... Better secure that pipe down, almost took off on ya!!!

I would say its time for injectors and glowplugs. Might also want to invest in some new fuel lines those are going to start leaking before long.

x2, injectors and glowplugs. Might also help if you let the starter motor turn over for more than two seconds, I used to have to crank mine for like five full seconds to get it to start when it was running it's worst, but it started a hell of a lot better than yours.

Once I get all the new GPs in ill see if its puffing still. Thanks for the help!

OK some updates;

I forgot to charge my camera over the weekend so I dont have any pics today but I dont really need any to eplain todays progress.

First thing I did was to pop in the new GPs. 6 are new, one I couldnt get too because I already clamped on the the downpipe and its barely holding on as is so I didnt want to mess with it. I pulled out one of the GPs with the tube around it and it was pretty much brand new. No corrosion and hardly any carbon on the tip so I put it back in.

Then I tested the lift pump. I opened up the T valve and turned the ign to on but not running. Nothing came out, good news! So I jumped the relay by powering the E wire and I heard it pump! good news! So then I put in the new relay figuring it was bad, no dice, still didnt turn on the LP. So I tested the wires that power the coil and the purple/white wire was not switching the coil on to power the pump. I traced the wire into the cab and into the glovebox. Then from there it goes over to the drivers side, I looked around for it but didnt want to split open all the taped wires so I just cut the purple/white wire and wired it to IGN. That worked. So I went to fire it up, started on the first try! VERY little smoke and sounded much better and ran smoother. The high idle kicked in right away. I let it run for about 10 mins, then romped on it a few times to see if I get that puffing smoke. NOPE! was all clear. Figuring it was too good to be true, I put the truck all back together and took it for a little spin, it ran great but It was so loud I couldnt hear anything (I straight piped it since the muffler was shot. I need to put another one back on, thats for sure) and I didnt want to romp on it since it was so loud. It ran real smooth though and when I got back to the shop, still no puffing. The only time I get smoke is a bit at startup and if I romp on it in park.

So I might be lucky enough to return the LP, OPS, and LP relay.

As for the shutdown switch, it gets power with IGN so its working properly. I went one step further and while the engine was running, it unplugged that pink wire and the engine stopped. So Its probably a problem with the key cylinder or elsewhere.

The next major project is getting the speedo to work and figure out that wiring mess. Right now, if your cruising on OD and then it needs to downshift into 3rd, it will but it will stay in 3rd or below until your turn the truck off and then back on. It was like that the whole summer but I delt with it since im just on local roads the whole time but towards the end of the season it went one step further and if it needed to go to 2nd, it wouldnt go back into 3rd until a restart. Im not sure if its related to the VSS not funtioning or not but the new VSS comes in on wednesday so Ill know then. Im hoping that is it or I will be very lost after that and not know what to do next. Any ideas on that one?