Well we thought we just blew a head gasket this weekend and so we pulled the motor out and were figuring on shaving the heads, changing the injectors and all that good stuff but it appears that it is worse. We got her all torn down last night and the #7 cyclinder was scored, then we when to look at the crank and was scored also - so something had to have gotten in my engine. The next thing we learned was that it had already been torn down once (silconed oil pan) I bought this truck when it had 69,000 miles on it in 2002 and now it had 119,000 miles on her. What the heck would cause someone to tear it down with such low mileage. When I got the carfax it seems it only had a couple owners and was pretty much moved from dealer to dealer. It didn't get a registration for personal use until it came to the US in 1998 (it was a Canada truck) The worst part is I still have a year to pay on the darn thing. :(

Do any of you have any suggestion on where to look for a good priced rebuilt motor. I found a place that I saw someone mention on one of these forums (http://www.gm-diesel-engines.com/index.html) and didn't know if anyone new anything about them. Any suggestions would be great, I already miss my truck (gotta drive the bloody Dodge Neon):help:

Diesel Chick,

Scoring of your piston/cylinder is/was caused by excessive heat. This could have been either excessive egt's or coolant or a combination. Don't blame the poor 6.5 on this one. I have seen many Cummins and Powerstrokes with the same problem. Heat kills. Usually the problem is too high egt's. This is why the installation of a pyrometer is of vital importance.

As for replacement engines, check ebay motors. From time to time there are still some oem crate engines floating around that have been dyno tested and there are also other reputable rebuilders and some are offering free shipping. Contact as many sellers as possible and make an educated decision. If you decide to go the route of rebuilding the engine yourself, there is a company that has been selling good quality Mahle rebuild kits for the 6.5.

Finding a GOOD machine shop is the trick. There is a good chance that your crank can be turned .010 max. The scored piston probably caused the damage to the crank when the piston stuck in the bore.

Sorry for your misfortune, let me know if I can be of assistance, as I have rebuilt many 6.5's.

You could always buy a new crank and a master overhaul kit and put in or make 18:1 pistons for cheaper than you can buy a short block.

Check this one outhttp://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33615&item=7974625030&rd=1

DieselChick,

What makes you think that the pan has been off before? The 6.5 pans all used RTV on the pans, no gasket, except for the rear of the pan. Was the RTV anything but black?

My boyfriend (whom is a mechanic) and his buddy who owns a garage and used to rebuild motors was the one who told me it had been torn down before. I can't give you their exact reasons I would have to ask them.

Quick question though - did all the 6.5 come with graphite head gaskets?

Also where can find these rebuild kits you are all talking about?

www.rockauto.com (http://www.rockauto.com/) is a good place to start. It has pictures, part numbers and different brands of OEM parts.
They listed .25mm over, .50mm over and .75mm over rod bearings.
Look on ebay they have 6.5L parts cheap sometimes.

[QUOTE=D.Camilleri]Diesel Chick,

Scoring of your piston/cylinder is/was caused by excessive heat. This could have been either excessive egt's or coolant or a combination. Don't blame the poor 6.5 on this one.
QUOTE]

I don't blame the 6.5 - I still love my truck and the sad part is that it pulled so great this weekend. Heck it ran great even after the head gasket blew. I guess that is what I get for wanting to go to a horse show during the Friday the 13th weekend - won't due that again

Sounds like a good time to go to the 18:1 pistons and overhaul her and enjoy many more years of service. Also sounds like you have most the labor paid for too. ;)

I agree with D.C. get your engine rebuilt with all the goodies for about 2/3 of what a short block would run you. There's a co. out there that rebuilds these engines for a premium price that I can't afford but they offer their heads seperatly worked over with drilled cooling passages between the valves, If your interested I'll dig up the e-mail and post it on this thread.

Any directions you fellows can give me would be awesome - names, emails, I may not understand what you tell me but I plan on just taking the info to them and have Nate and John figure it out. Just for curiousity purposes - how much does it normally run to do this work and second how long will it take (approximation)

Thanks!

I found this rebuild kit on ebay - what do you guys think?
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7974082255&category=33620&sspagename=WDVW

For a little more they will sell you 18:1 pistons instead of stock or you could offset the wrist pins to lower the deck heigth. There may be an offset wrist pin available, iirc.

Diesel Chick,

I have recommended this company before. Seems to be good quality parts for a fair price. If you go to their web site I believe they also have short blocks available with standard compression and 18:1. I believe Turbine Doc ordered a set of 18:1 pistons from this vendor but I think they were back ordered. One big consideration that I have for rebuilding the 6.5 TD is the quality of the pistons. The oem pistons are good, but I have had some bad experience with some aftermarket pistons. Silvolites to be exact, had a piston turn to gravel after 50,000 miles:mad: destroyed block. This vendor sells Mahle Pistons and they seem to be a good choice.

Here is a link to their web sitehttp://www.diesel-direct.com/webcat.php?sel=3&bnd=11&a=2:grd:

I talked with Nate alittle bit today (he is at work hauling milk) and we both agree we are going to do the 18:1 pistons - so if we bought this rebuild kit we would upgrade. The only thing is we don't know whether we have to have the pistons before they machine it or not. Anybody have any imput?

Get the pistons BEFORE any machine work on the block (boring). They will need to measure the pistons to be sure the get the piston to bore clearance just right. You don't want one of these engines with loose pistons, nor too tight as it will start to gall (grab the cylinder walls) just like you described on #7. If the machine shop doesn't think it's necessary to have the pistons before the bore, then start looking for a better machinist. Different brand pistons do have a slightly different size. A .030 piston is not always the same, they do vary. Also make sure they're aware that #7 & #8 cylinders will need to be slightly oversized to compensate for heat. This is the GM spec and has been around since the 6.2L. If the block is bored straight .030 or .020 (if it'll clear that) on all cylinders, you'll have problems with the back holes pretty fast. You might at the very least before ordering the pistons, take the block down to the machine shop and have them measure the bores on all the cylinders, that way you'll know what size pistons to buy. I'm sure the block has to be bored because it's stock bore with a scuffed cylinder, but shoot for .020 if possible.

And last but not least, check for main webbing cracks before buying anything! If you've got a cracked block, you have a new donation to the local scrap metal yard. So it's best not to have already bought pistons etc. and have to hunt down a block (it's not easy).

Diesel Chick,

I have had some bad experience with some aftermarket pistons. Silvolites to be exact, had a piston turn to gravel after 50,000 miles:mad: destroyed block.

I think the KB pistons are great. I never had an issue with them. I guess every company makes a bad part from time to time.

Thank you all so very much for the imput - I am printing your posts up to take home to Nate and John. I will let you know what we decide upon and I am sure I will have plenty of other questions to ask you.

For a little more they will sell you 18:1 pistons instead of stock or you could offset the wrist pins to lower the deck heigth. There may be an offset wrist pin available, iirc.

What is the stock compression?

Stock compression is 21.3:1, boring the cylinders oversize increases the compression ratio due to increased volume in the cylinder.

Another thing to keep in mind is the possiblity of sleeving the #7 hole and depending on the condition of the other cylinders, put in 1 new piston in the sleeved hole and re-ring the rest. This is just a low cost alternative to having to spend a lot and without knowing what condition your block is in you will have to make that call.

They are going to take a look at the block tonight I will let you know the outcome.

I cannot overstress the NEED for high capacity cooling system upgrades...

:exactly:

Our next step was to get the upgraded water pump. We already had the fan and fan clutch and since we put that in our truck never got close to how warm it would get when we would pull without the upgrades.

High exhaust temps is probably what did in your #7 piston. Piston gets extremely hot(1300 F or more) piston is aluminum, aluminum expands as it is heated, if it gets too hot, bad things happen, holes in pistons, cracked pistons, scored cylinder walls. The ONLY way to prevent this is to install a pyrometer and watch the gauge religiously. With your very tall gears, you will have a much harder time keeping EGT's in check, it will require backing off of the throttle or down shifting. I have towed many thousands of miles with a modified 6.5 with 35 inch tires and 4.10's(equals 3.73 and your tire size) and the only times I had problems was when I pushed the envelope on the exhaust temps and then bad things happened. My final version was an 18:1 version and it never gave me any problems other than trying to keep water temp down on hot days. With my set up I was always pulling between 9,000 lbs and 15,000 with a max combined weight of 23,000. I would also recomend not exceeding 10 psi of boost with 21.3 compression or 18 psi with 18:1 if you want your head gaskets to last.:cool:

Quick question: Wouldn't you lose power by going to the 18:1 compression over stock? Plus would having to shave the cylinders 0.030 would that weaken it and possibly give me more problems eventually. It is the main towing truck and we haul our 14,000# trailer regularly during the summer and I need to know if I invest this sort of money is it going to be able to endure hauling this sort of load.

What was the EGT and boost when the engine went down?

The key to the cooling mods is getting the heat out of the engine and into the coolant more effectively. This will not necessarily show up on the temp gauge. I've even heard claims of seemingly running warmer on the gauge as temps become more uniform across the engine as the stagnant flow areas are picked up.

What was the EGT and boost when the engine went down?

The key to the cooling mods is getting the heat out of the engine and into the coolant more effectively. This will not necessarily show up on the temp gauge. I've even heard claims of seemingly running warmer on the gauge as temps become more uniform across the engine as the stagnant flow areas are picked up.

John she didn't have gauges. :eek:

You are correct I don't have guages - when we did the first upgrades (fan, clutch, turbomaster, exhaust and eprom) we asked Bill about guages. We were going to purchase them also mostly because we figured we would need it with the eprom. But he explained that the eprom doesn't work like a hp chip it is more or less a computer chip to help you truck more effeciently - like the shifting in our transmission and that it is set up to work with the turbomaster. He stated that as long as we didn't try to win the race to the top of the hill we shouldn't have any problems. Which we never laid into her we let her climb the hills at her on speed which normally was about 55 (Bill stated that if you are going at 65 and she pulling a good hill just lay back and let her do it at like 50-55 which we did.) The area I went to was really not hard driving and we didn't run into any hills that we had to really climb on the highway we were able to swoop pretty much all of them. I really am going to lean toward the idea that we most likely weakened the gasket a good deal this past fall when we went to VA without any mods pulling our trailer. It was then we realized that the truck wasn't running very well. I unfortunately didn't find this website or any other vendor that dealt with these 6.5 til this past winter. We both wish we had find these sites earlier and we would have done the mods first before we ever hooked on to the trailer. But these are the mistakes we make and the price we have to pay. Nothing we can do about it now!!!

Quick question: Wouldn't you lose power by going to the 18:1 compression over stock? Plus would having to shave the cylinders 0.030 would that weaken it and possibly give me more problems eventually. It is the main towing truck and we haul our 14,000# trailer regularly during the summer and I need to know if I invest this sort of money is it going to be able to endure hauling this sort of load.

18:1 is harder to start cold and low end power is diminished but you'll make it all up in the top end.

it's a '94 block, removing .030" isn't going to ruin it.

Diesel Chick,

In theory lowering compression to 18:1 will reduce hp at the same level of boost as 21.3:1, but with lower compression there is more area to force more fuel and air and thus increase power dramatically. Most people don't understand the dynamics of increasing boost on a stock engine. The stock engine is designed with 10 psi of boost. When we start increasing boost to say 20 psi, you would think that cylinder pressures have just increased by 100% but in fact they have gone up much higher than that. I am sure there is some one on this site that is a better math whiz than I that can chime in and give better numbers. Bottom line is lowering compression tends to help the engine live longer(as proved by penninsular diesel in marine applications) their main objective was for engine reliability and longivity.

Your next improvement before all else needs to be gauges! :exactly:

Hey Diesel Chick;

Sorry about your truck you may have not done the damage it could have been done long before you bought it and it just showed up. Ronnie Joe is a good example he thinks he damamged his engine 10's of thousands of miles beofre it finally gave up. So don't beat yourselves up too bad. I hope you get this thing bakc on the rooad in a reasonable time. Good luck!

16gaSxS makes a good point on the pre-existing conditions theory.

Gauges are the FIRST thing that every 6.5 needs and (I believe we spoke on the phone) my first recommendation. Exhaust and cooling mods are equally as important and difficult to prioritize.

I don't know why you were given the advice that you were and must really scratch my head at this one. Adding any amount of fuel and adjustable boost control without gauges is not something anyone should recommend for the 6.5 especially one that is towing...

Diesel Chick,

I have recommended this company before. Seems to be good quality parts for a fair price. If you go to their web site I believe they also have short blocks available with standard compression and 18:1. I believe Turbine Doc ordered a set of 18:1 pistons from this vendor but I think they were back ordered. One big consideration that I have for rebuilding the 6.5 TD is the quality of the pistons. The oem pistons are good, but I have had some bad experience with some aftermarket pistons. Silvolites to be exact, had a piston turn to gravel after 50,000 miles:mad: destroyed block. This vendor sells Mahle Pistons and they seem to be a good choice.

Pistons finally arrived their vendor that cuts them down was behind, I'll have to shoot photos I'm away from home till the end of the week, they are std pistons tops shave to get 18:1, tops have been re ceramic coated. Mahle is cast inside them so unless bootleg copies I have to take it that they are true Mahles Diesel Direct stands by them and says no problems to date with them.

Pistons finally arrived their vendor that cuts them down was behind, I'll have to shoot photos I'm away from home till the end of the week, they are std pistons tops shave to get 18:1, tops have been re ceramic coated. Mahle is cast inside them so unless bootleg copies I have to take it that they are true Mahles Diesel Direct stands by them and says no problems to date with them.

Now you lost me here. Mahle has not released any 18:1 pistons. I don't see Mahle standing behind any modified piston. I have spoken directly to the regional sales director over dinner about this...

We had every intention of putting the guages as I stated on another post. The items we purchased except the eprom - we needed to get due to the failure of a stock product. In the last year I have spent over $2,000 on this truck (half of that is because a local dealer didn't know what the hell he was doing and freaked screwed me!) So we weren't planning any big trips for a least another month or two - in which before we would go we would have purchased the guages. Not to count that this couldn't have come at a worst time - there is nothing I can do about it now. All the coulda's, woulda's and shoulda's don't matter right now.

Kennedy - yes I talked to you when I was looking for prices (or at least I think it was you) and I also needed a price on a CDR and you told me they never go bad and that wasn't the problem - But other people have told me that these are common maintance items that need to get replaced. I am not saying you are a bad person and again I appreciate everyones help I am just stating the facts. We did the CDR and the problem was fixed.So the first things we went with were items to fix the truck (the eprom was simply a better priced to buy with the turbomaster which I needed because my waste gate was sticking open and I was throwing all my fuel out the exhaust - which also needed to be replaced because I had a hole in it) so that is what I went with. Had the truck been running completely normal I would have bought the guages first before mods but it wasn't. These forums are filled with a wealth of info and sometimes it is difficult to seperate the information that you need.

I guess if yours was bad it was bad, but typically they do not go bad OR can be cleaned and put back into service...

I hope I didn't come across as mean - I already feel awful enough about my truck being down without being told what I did wrong. So I do apologize if I have offended you but when all I can hear is guages guages guages (and I do understand the importance of guages) but I just want everyone to understand my predictiment so that I am not dubbed as the ignorant one who didn't take anyones advise about guages. Again I didn't mean to offend you.

You're not the first to have to rebuild after a haul. Live and learn.
A few here with all the mods and gauges have blown the motor hauling. Haul and rebuild.:D

Hi folks,

Why not just buy a Peninsular Engine and drop it in? Done! Are they still doing 6.5s for trucks? Are they still in business? Do they suck?

As I recall they use the new Optimizer blocks and their prices aren’t too bad. And I think you can pick what type of performance level (18:1s, hp levels, turbo type ect.) I’m planning to do this when my 6.5 dies and at 225k mi. its probably soon.

Just a thought.

-John

Where do you find these engines?

Most of us that make recomendations do so because we have already learned the hard way and gone through the hole in the wallet routine. So we speak from hindsight so that the next person might escape the same feeling of oh-s***. Once you have gauges you will understand what we are talking about just by looking at your gauges. ;)

My boyfriend hauls milk with a Kenworth with a CAT under the hood and it has all the guages you can imagine and he showed me each one and what to watch for when he is driving (I ride with him) He was the one who really really wanted the guages but at the time we talked ourselves out it for the time and decided to pay this down some and in a month or two buy the guages. So I actually do know what you are all talk about in regards to the guages and what not - it is a little bit different then the big rig but same concept. Like I said I really don't feel we damaged it this weekend - but I will bet you ten to one that we did something to it back in the fall right after we bought the trailer - more then likely our trip to VA when we took 68 through WVA (BAD BAD BAD IDEA) But like you all say you live and learn.

Good that you know what to look for on the gauges, but I think what D.Camilleri meant was specific to the 6.5. I can speak from experience (I drove logging truck for a while) and when you put gauges on a 6.5 it will plain scare the hell out of you! If anything, it is amazing that these things hold up as well as they do when you see how high the egt can get with what you would think is a realitively easy pull. I don't know for the life of me why these things didn't come with a pyrometer from the factory. You'd think it would have saved GM millions in warrantee claims. Sorry that this had to happen to you though. I don't wish that on anyone. Well, steaksauce maybe, but no one else.:)

If you are interested, http://www.peninsulardiesel.com/If you are on a budget like the rest of us you might say ouch at some of these prices. However, these were the 18:1 pistons that I bought, mainly because they are factory gm pistons with an offset wrist pin location to lower the compression. They were pricey however at about 1250.00 for just the pistons.:eek:

Now you lost me here. Mahle has not released any 18:1 pistons. I don't see Mahle standing behind any modified piston. I have spoken directly to the regional sales director over dinner about this...

Mahle is is original source, Diesel Direct is modding them and standing by them

Alright I did some emailing and phone talking and I thinking to save on time and labor we are going to send our engine to Direct Diesel.(turnaround time door to door around 9 days) They seem to be the best price and have done plenty of these (from what they told me they just got a contract from the army to rebuild their 6.5's) We are going with the 18:1 pistons and they are going to put in remaned marine injectors. We are then also going to purchase the water pump upgrade and the very important pyro and boost guage. Can anyone suggest a place to get a good pyro for decent money (they are a little pricey but we gotta have em)Hopefully after this my truck will run wonderfully and do it's job to pull the trailer for the next year or two when we purchase a newer bigger truck.

I don't know about price wise but don't get a cheap one. AutoMeter and Isspro are the best from what I understand. By that I mean most accurate. I think Isspro makes the gauges for most aftermarket kits like Banks and BullyDog. When it comes to a Pyrometer, the accuracy could mean the difference between a great trip and another rebuild. You might try Summit or Jegs. I'm not sure where the best places are for pricing in the US. Sounds like you are gonna have one hell of a 6.5 though!:ro)

I'd skip the Marine injectors. The pressure is to high and will not improve performance. Delphi stock replacement injectors would be the best injectors. The "marine injectors" are designed for mechanical injection pumps.

I've got Isspro gauges, boost and EGT (though EGT is not fully installed yet). I like them very much because of their apparent good quality, and, if that is a concern to you, they nicely match the design of the stock instrument cluster.

They are not the cheapest ones available (and not the most expensive), but imho well worth their money. Kennedy sells them, maybe others, too.


BTW, sorry about your having big trouble! I hope you can get your truck running fine again soon!

Hm, have you considered an additional trans cooler? Since you are to do some major work, this might be a good occassion to install one.

I'd skip the Marine injectors. The pressure is to high and will not improve performance. Delphi stock replacement injectors would be the best injectors. The "marine injectors" are designed for mechanical injection pumps.

I talked with Diesel Direct and they have rebuilt over 300 6.2 for the army and they just recieve a contract to do 300 6.5's. To them doing the 6.5 are the easy jobs just because they have done so many of them. In these he recommended me to put in their reman marine injector which they reman themself so they have set them up to work with my motor. Everything they do is done in house that is the reason they can do it relatively affordable. :ro)

Hey DC:

thats good news, sounds like a feasible plan. What price range did they quote you?

-John

Hey DC:

thats good news, sounds like a feasible plan. What price range did they quote you?

-John

They quoted me about $3,000.00 shipping , remaned injectors included and 18:1 pistons. Still pricey but they were the best price I got and they seemed really comfortable with these motors. :grd:

They quoted me about $3,000.00 shipping , remaned injectors included and 18:1 pistons. Still pricey but they were the best price I got and they seemed really comfortable with these motors. :grd:

I think that is a good price with the 18:1 psitons and cooling upgrade, now hope your head and block are good. It's pretty easy to get $5K into one of these engines.

I hope the block is ok - we didn't see any cracks when we got her apart and hopefully they don't find any when they rebuild her. Heaven knows I don't want to put that much into her as much as I love her 5k is still an awful lot. Keep your fingers crossed!

how about an update, like to hear how it went.

Ask them what tip nozzle they are using and what pressure are they set at. Are they using new nozzles? Inquiring minds want to know.