OK guys give me some help here. I purchased a 2000 3500 Crew 6.5. It has 100k on it and drove great for 6k miles. I immediately put AMSOIL in it replaced/moved the PMD cleaned out a blocked heater core from the #)$#)*$ that GM uses for coolant. I noticed I had a minor leak in coolant system somewhere as I was losing coolant but it wasn't leaking on ground anywhere didn't affect anything just noticed losing heat at times a occasionally coolant light would come on after couple of weeks. So threw in some stop leak & pepper and leak seemed to slow leak haven't had problem since. Just last Friday I put exhaust on truck 3in down to 4in and now truck is blowing through oil, I mean it is wet at tail pipe. I went through 4 qts yesterday. Still holding 40psi pressure at idle and it's not smoking while running excellating or even heavy accelleration. I have noticed a puddle of oil in intake valleys on passenger side. Any ideas? I am going to do some leakdown testing to make sure I haven't hurt rings, which I don't know how that would have happened. I think pistons are OK since it's running perfect still. I seen a lot of posts on here regarding cracked blocks, EKKKKK. What about turbo seals? I have 3 other turbo cars so I'm somewhat fimiliar with this stuff give me some help please

Time to pull the heads for freash gaskets at the least if not rebuilt heads. Where are you at?

TJ Welcome to the site,
I feel for your 1st post being one with a significant problem, off hand I'd say you are looking at a head gasket job. Is this a K3500, update your sig line in user CP tab, visit FAQs & welcome note above, see what RPO codes in glove box say & let us know what you are equipped with. Even with all horror stories of cracked blocks you may not be that bad off, if you are 2wd your task is easier, remove pan, then with acetone, or alcohol wipe down surfaces, take a break consume an adult beverage or 2, then come back and look for spider webbing from oil trapped in crevices to weep out, will sort of work like a die penetrant test, except your own oil will be the penetrant.

Since you are not the original owner you don't know if 1st owner towed it hot, any mods done to it before you got it you don't know about like boost foolers.

Would the upgraded exhaust cause or highlight the possible headgasket problem. From my past turbo issues it could have due to increased boost pressure, but these trucks seem to control boost through ECU so I didn't think that was a problem. Which brings me to another question, how can I increase boost on these trucks, when problem is fixed of course!!

I think that the aftermarket exhaust flows better and your just noticing it more due to no soot trap or muffler to clog up. You mentioned the leaking and trying to patch it with radiator stop leak, it may have deteriorated further since and started flowing oil. No telling how streatched your headbolts are, increasing the gap.

Visit FAQs I've detailed there what has worked for me, exhaust should help not hinder, nor cause the problem, I suspect it has had an overheat a time or 2 and has put your headgaskets under undue stress, but that is just a opinion/guess.

Did you buy from an individual or dealer. The PCM can be fooled into making more boost, but unmonitored boost & EGT levels can lead you to what you are having, PCM does not limit engine on EGT no sensor for that from GM, rpm, fuel, IAT & boost are mainly what PCM regulates on.

As a 3500 I'd be willing to bet previous owner/s probably worked it some, did it come with a 5th wheel or GN setup in the bed, or sway bar connections on the hitch, if driven without EGT monitor previous owner may have pushed the envelope some, not knowing any better hey it's a Diesel supposed to be worked hard.

I see from sig now that it has gauges & exhaust upgrade, you add that or previous owner.

So your leaning more towards headgaskets than ring or piston damage? The amount of oil it is comsuming has me worried. 4qts yesterday. Eventhough there is huge puddles on intake in the valleys. I hope it's only headgaskets. BTW can you give me the skinny on those CAMS.

So your leaning more towards headgaskets than ring or piston damage? The amount of oil it is comsuming has me worried. 4qts yesterday. Eventhough there is huge puddles on intake in the valleys. I hope it's only headgaskets. BTW can you give me the skinny on those CAMS.What do you mean hudge puddles on the intake? Putting out oil in large amounts is a sure sign of trouble. Usually when you crack a piston it will start throwing oil out the dipstick tube due to all the compression being forced into the crankcase, but this will give you a major cylinder imbalance, one you should be able to see at idle.

The Cam is $125 from Delta Cams of Tacoma Wa. It has an increased duration and intake/exhaust overlap. It will come soon and I'll post the duration numbers it comes with.

QM
Any way you can do some before & after testing say on dyno or with G-tech, 0-60 unless you are at a track with optic time trap has some fudge factor would be interesting to see what gains you get.

TD,

EGT and boost gauge were added by me immediately, and I know that previous owner used it to haul their 5th wheel camper so I'm sure it was worked some.

QM,

Puddles of fresh oil seem to resting in intake valley's on passenger side of motor. I noticed that late last night. I plan on taking to spray wash tonight blowing off intake valley and seeing if I can see where oil is seeping while running. Truck still runs very well and does not smoke at idle, start up or acelleration. This is why it's got me stumped.

Td, sorry no chance of any testing before hand. My and my father's SOP is the only factor I'll compare, but if I like the cam I'm doing all my trucks and one of them might get a before and after dyno to illustrate any gains from a cam only. Ideally it would not come as the only mod but as part of lowering CR a point or two and installing a higher volume turbo.

Oil coming out of the exhaust is almost always a bad turbo. Inspect drive side of turbo for play, check outlet of turbo for signs of oil, make sure there are no resrictions from turbo to engine on return side oil line. Out put seal on turbo is ceramic, if end play isn't excessive might be able to rebuilt with just a kit. Clean engine galley and try to determine source of oil there, could be a switch that is leaking. Let me know what you find.;)

Duh goes to show how one can become fixated on one idea, good thoughts DC.

Daily update on problem, which is getting more and more confused. Last night I did a complete steam clean job and filled with oil to see if I could see any oil seapage anywhere. I saw nothing so I keep truck running putting it under load and checked for oil getting pushed through dipstick, oil pushed up through filler neck, oil pushed past VC gaskets, oil blown through breather going back into turbo, oil leaking past filter (then changed) oil blown out exhaust. The answers were none on all of them. Where the hell is it going? Going to be driving around town today and check to see if it consumes as much as day before, which it has to I assume.

DC

Going to check turbo end play tonight. What and where are the switches located that could be leaking? I see the oil feed line for turbo, where is the oil return?

TD

Not fixated on any one problem just trying to cover all bases, I assumed with the amount of oil truck was/is consuming it had to be someting larger than turbo problem. I own 3 other turbo vehicles none of them are diesels, so that's why I am looking for a little help tracking down problem.

The turbo oil return line is directly under the center section of the turbo and goes down to the oil pan which is then connected there with a rubber hose and hose clamps. Not a great system, I had the hose slipoff the fitting on my 94 once while pulling a hill with my car trailer. As luck would have it, there was a convenience store at the top of the hill and I stopped to get a coffee, left the truck running and a passer by saw the puddle of oil growing at an alarming rate and came in the store to tell me. Whew. Thank you good samaritan!:ro)

There should be some sort of a oil pressure switch located under the intake manifold towards the rear of engine. The turbo oil return line should be a steel line that comes out of the bottom of the turbo and routes down to the fuel pump block off plate on the block. Any restriction of this line could cause oil to be forced out of the rear seal of turbo. Oil coming in from the cdr valve will have no effect on oil loss, it is simply burned in the engine. Be vary careful of rear turbo seal failure, it can empty your crankcase in a matter of minutes!

I am sorry to here about your problems. I sure do hate when owners knowingly pass on a money pit to some poor, unsuspecting soul. Good luck!

on a '93 it will be behind the right valve cover at the firewall.

DC

MMM pinched line causing seal failure!!! I had a friend of mine install exhaust at his shop I wonder if he moved line during install and caused pinching or kink. That would explain why I started losing or burning oil after exhaust install. I will check that tonight too along with swith.

Juancho,

I did think I inherited a bad truck with problems, it has been very good so far, something had to have happened during exhaust install or because of exhaust install

More to check -
The valve cover(s) are leaking - RTV - and could also be the oil pump drive paper gasket, back where the dist would be on a Chevy V8.
Could be the Inj Pump is loose, or the gasket is damaged, leaking oil from timing cover.
Could be the Oil Pressure Sender, in the valley on later blocks.

The turbine shaft\housing seal is labyrinthine type, depending on centrifugal force and exhaust gas pressure to aid in sealing process.
Could have cracked turbine housing, but leaks of that type would result in really heavy blue oil smoke, in quantity neccessary to 'wet' tailpipe.

Three quarts a day would leave a Brea tar pits-sized puddle under the truck at each rest.

Losing coolant - could be head gasket, if you do not see a puddle under the truck.
Water pump could be leaking, with accesssory drive slinging the coolant off in multi-directions, giving it more chance to evaporate
Could be heater core, inside truck, or hose connections at firewall or t-stat manifold or radiator.
Could be leaking radiator hose, or water-jacket gaskets, two at rear of heads, two at t-stat crossover, incl both t-stat 0-rings.

Absolutely should NOT have put stop-leak and pepper, or oatmeal, or cream-of-wheat, or corn-grits, corn flakes, cheerios, or any other 'patch' into the 6.5l coolant system.
A hair-thin line exists between cooling and cooking in this engine - easy to cross, even without any 'help'.
Check every joint and hose\connection and heat exchanger for leakage - then head gaskets.

And - the heads will require acid-vatting, to remove the stop-leak type coatings, if you plan on keeping the truck.

GMCTD,

Well that's a hell of a list. I will run the list but I have already done a spot check on most of these. VC are not leaking verified last night. Checked oil pump drive no sign of leakage, no sign of leakage from timing cover. There is no oil leakage at all so no tar pit size puddle ever appears. I'll check oil pressure sender tonight and turbo and turbo oil return line. As for Inj pump, oil is supplied to that? I narrowed the coolant down to small leak in head gasket somewhere as I checked all coolant runs and connects prior to the "hillbilly" repair of stop leak/pepper/oatmeal and any other substance I could think of to seal leak. I was minor causing me to add 1/2 gallon of water 4-6 weeks. I was trying to save head gasket repair till summer when wheather is a little warmer up here in MI. I've learned my lesson. It's got to be something obivous cause up till exhaust install truck was running perfect with exception of minor coolant evap which didn't effect performance of truck. The only thing changed in past couple of weeks is exhaust.

Make sure the radiator cap has a good gasket. If it's cracked it's not sealing.

When I bought truck it was generating any heat so I flushed radiator, found out the coolant clogged heater core blew lines out replaced coolant with the non Dexcool (that stuff is crap) coolant replace rad cap and whoala!!! I had heat. Well then **** I found out I was using coolant in small amounts as I stated above, but again I could live with that at the time just filled every 6 weeks or so. I wish I could whoala this dam oil problem.

Didn't use oil before exhaust was done, uses tons of oil after exhaust? He didn't pull the turbo to do the exhaust did he? Maybe theres a rag/obstruction in the return oil line under the turbo, when i pulled mine i put a rag in it to stop debris from falling in while i did my injectors. At the very least i'd pull the turbo and check it out before its to late!

Turbo is getting pulled tonight to check along with a couple of other things. As far as oil usage before exhaust, if it used oil I didn't notice. I changed oil as soon as I purchased truck, check it regularly the first couple of weeks and didn't have to add any. Well then I haven't driven it much in the past couple of months my wife has been putting most of the miles on it. In a fit of rage the other night I asked her if she has checked oil lately and her answer was of course no!! She noticed light (check gauges) and lower pressure that usual on day after exhaust install pulled into gas station checked oil and was low had to add 4 qts. I checked it when I got home the next night after a trip she made with truck (couple hours) and was low on oil again. Filled yesterday and drove around all day and ran for 1hr idling and no apparent loss last night. I will check again tonight and give you guys update.

I bunged that seal putting the turbo back once. It leaks a 1/2qt a mile.

Don't fret the 4 qt down. I changed someone's oil who wasn't maintaing it
and only 1 qt came out and it was thick and gooey!:eek: I asked him if he checked his oil regularly and he said"no, but the check oil light came on this
morning."
That 6.5 has done another 100,000 mi with maintainece since then.

Guys,

Thanks for all the help I just found problem. I took snorkle off turbo and low and behold outlet of turbo was coverd in oil. So I reached in to check endplay on shaft and it was wobbling around like a hot dog in a hallway. So now here's the next plan. I have to either get thing rebuilt, buy a new one, or upgrade. If I chose to upgrade what's the best route. I mean what are the A/R rating on stock turbo, and what is the biggest I can go safely. My friend has a brand new Garrett 60-1 turbo with a huge hot side housing. It's from a Bentley. It appears to be for an application of bigger engine lower boost pressure if I look at flow maps of turbo.

Made few more calls. I have a friend with a brand new Holsett from a Dodge and a Garrett from a Powerstroke. Is this something I can make work with a 6.5 application.

Machine a new flange if you have to and put it on!
PS or cummins will work.

What do you mean by 3.5L-5L gasser turbo

if the bently was 3.5-5L in displacement it's turbo would flow enough air.
BTW bearing kit is $75 usd
Google j&h turbo

Oil in the compressor inlet is from the CDR cranckase evacuation system, and is normal.
Doesn't hurt a thing - Diesel fuel is light oil - and serves to lubricate intake valves.

Turbo shaft will have seemingly excess play when cold due to full-floating bearings - oil pressure and heat do the trick, providing correct clearances when engine is running.

Turbine and compressor wheels should not touch housing at any point when cold - up\down, sideways, in\out.

Check exhaust flange and turbine wheel and outlet elbow for oily - that would be a problem.

I understand there is some shaft play when cold, but shaft in this turbo is hitting housing all over the place. The oil in compressor housing is not light it's completely coated heavily. Finally when shut engine down turbine wheel did not continoue to spin. I am used to turbine wheels spinning after engine shut down. I am going to pull turbo off tonight to give complete inspection, but I've never seen a turbo with that much axiel movement.

Oil in compressor housing and intake manifold is normal; heavy oil is normal, accumulative over 100k miles.

The GM-X series turbos do not often fail, due to the maintenance routine schedules for a Diesel.
Very intense, compared to a gasser truck.

Wheel(s) hitting housing is not normal - could indicate way-extended oil change intervals, poor maintenance to the extreme.

Exhaust flange and outlet elbow will indicate oil leakage thru exhaust side of the shaft.

Seals are centrifugal and labyrinthine, because diesel intake charge contains no fuel, which would contaminate engine oil when scroll is pressurized.

Spin-down is normally minimum because of low exhaust gas energy\velocity at idle, and 40wt engine oil viscosity at 40psi@idle.
Listen for your lift pump after shutdown to get a sense of rate of oil pressure drop.

Wheel-to-housing contact is your clue.

I'm still having trouble with your '4 quarts' of oil 'a day', tho, with no tell-tale blue smoke, and no under-vehicle puddles.

Like someone else said play in shaft is not excessive unless impeller can contact the housing. I would remove turbo and inspect, oil on inlet side is from cdr and of no concern, look for oil on outlet (exhaust side) it should be dry, if it is wet, take it apart. Should be left hand threads on compressor wheel, you are looking for condition of shaft. If scored or worn you will need another turbo. If shaft is good a rebuild kit will get you going or contact US Diesel parts.com and ask for Moe(or curly or Larry:muahaha: )just kidding. Those guys rebuild turbo's in house and have exchange units as well. I wouldn't experiment with turbo sizes unless you have an expert size it for you, because there is a great chance that you will have drivability issues.:grd:

The oil in compressor seems to be fresh oil, it's not a "caked" build so to speak. It seems to be streaming out of compressor wheel although when I start with snorkel off there was no oil spewing out of wheel so I see your point. Can you guys define "excessive" play in turbo shaft. My other cars have minor end play measured in mm. The end play (side to side movement no fore/aft movement) could be measured in 1/4 inches it seems way to excessive to me, but you guys have been messing with these things way more the me. I'm going to pull turbo tonight to inspect.

Excessive is having .5" or more movement back and forth, up and down. It will growl above 1500 rpm as the intake wheel grinds on the compressor housing. There's an oring between the cartridge and the intake wheel that will spill oil from behind the intake wheel when worn.

You should be able to spin the intake wheel easily with your fingers. If it's hard to turn, it's not working right.

Remove your CDR valve and clean it with solvent. It probably has a whole bunch of oil built up in it. This is an often overlooked maint. procedure. They should be cleaned every 15,000 or so. Excess oil inside lets oil get past it and into the turbo. With engine running and oil fill cap off, how much blow-by do you have? The CDR's function is to separate oil vapor from solids allowing oil to return to crankcase. Sometimes they don't work so good. Still you did say you saw oil coming out of your exhaust pipe and that leads me to tubo seal failure on the exhaust side, inlet side oil usage is possible but I have not ever seen it. If your side play is as excessive as you say you should be able to make the impellers hit the compressor housing. There is only room for less than 1/8th inch before the impellers will usually hit. Good luck.:eek:

DC,

With engine running and fill cap and dipstick out I have absolutely no blow by. That's a strong statement I know but I don't see any oil coming thru dipstick or fill cap. I even applied some load to motor (the old fashion break torque) still no oil through either opening. I will clean CDR valve, it due for new one with 100k miles on truck? Do they go bad?

I've been told that cleaning the CDR is a bad idea. It ruins the rubber diaphragm in them. This may or may not be true, but for the $20-$40 a new tuna can costs, you may as well replace it every 10,000-20,000 miles.

You can clean them but don't use gasoline, use diesel or solvent. Over time they do need to be replaced, but I prefer to clean them regulary. No blow-by is a very good sign.;)

D.Cam is correct - for pre-'84 CDR System, where filler cap is filter with screen mesh.
The cap should be cleaned every 30kmi - sooner under dusty conditions

W.huis is also correct - the 'tuna can' CDR on the valve cover, and pre-'87 oil fill tube, should never be cleaned - solvents can dissolve the live silicone-rubber diaphragm.
The additives in Diesel fuel can accelerate the deterioration.

It is a very-low-pressure regulator - ~6"H2O, where 27"H2O is 1psi - closing to prevent raw oil in the valve covers being drawn into the engine intake system.

The early series would fail when the spring\diaphragm assy would rust, and some have failed with ruptured diaphragm.

CDR is fully open to crankcase, with normal intake vs crankcase pressures - as turbo spools up, lowering pressure in the intake duct, CDR should start closing, fully closed at ~6"H2O at 2000rpm.
Wouldn't hurt to replace it.

No blow-by is good sign, at ~100kmi

Finally something good ahhh. Ok next question, on my 2000 which turbo do I have I see turbos GM4, GM6, GM8. Can you give me the numbers so I can see what I have. I have a line on one freshly rebuilt and brand new center section for $300 seems to be pretty good deal from what I've seen on net. I still also have a big garrett and holsett sitting in wings to, but appears it may not be the way to go from what I hear.

GM-8, stamped into the compressor housing.

The dash number -X generally represents the year of introduction, with -8 being the final version produced.

$300 is what a catridge would normally sell for, make sure it's for a gm-7 or 8 or it won't fit.