• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Coolant leak is back, Plus oil sludge! 88GMCtruck's 1999 K2500 L65 = more problems.

Quick update:

Pulled the waterpump off, no leaks between it and the timing cover. Picked up some roloc discs and have begun cleaning the important surfaces. On the Passenger side head there are cracks between the valves of 6 & 8. On the Driver side head there are cracks between the valves of 1 & 7.

Quick question:

How much play is allowed in the timing chain? That is, how loose can it be and still be fine?
 
I hate to weigh in on the negative side david, but #8 looks like it's been running pretty hot (evident by the "scuffing") and that increases the likelyhood of a crack.

Look at it very very closely.....
 
From the pics you definitely have water on the topside, gasket or heads. The scoring would let the coolant into the crankcase more then without it.

Your cheapest option is a take out engine. I would advise against running the engine with the scoring on #8. It will run, uneven, use oil, and have lots of blowby, but, it will run.

You sure the head gasket on #8 is good? The pics looked bad from the cyl to the end water jacket on the head, but, that could be oil from pulling it off. The top of #8 also looks bad - I would guess a crack at the top if the head/ head gasket is not the cause.

The cracks in the head can hit the water jacket.

Who knows what the bottom end of this engine looks like crack-wise.

Who knows if you bent a rod from near hydro lock.

GM gives you a 1/2" of play on the timing chain or in other words anything goes. I'd refresh the chain while you are there but only as part of an overhaul. They stretch out in less than 30K miles no matter what.

You could get lucky with heads only on your engine.
 
So far, I have found nothing to indicate where water is getting in the oil, if that is indeed what is happening. There was lots of rust around the lower portion of the waterpump where I found it leaking before. It very well could have been still leaking there after my tightening, due to the rust formation at the hose.

I'm still not convinced that a cracked cylinder wall would cause this, because I have never had any symptoms suggesting that: radiator hose doesn't even begin to build pressure till at least 5 mins into warmup, only get a puff of smoke on startup, etc. I do believe that it could be something with the head or gasket. Hell I just don't know. Truck was running great in every aspect aside from this interesting oil and the coolant loss.

Is it possible that this isn't water but is soot in the oil? Possibly from the turbo, which I did find to be quite in need of a rebuild.
 
I just had another thought.

Does anyone think that it would be at all possible that the PO was running a cheap oil, and this is the result of years of buildup of it. I ran Shell Rotella T, which i know is a detergent oil. Maybe it started to break the sludge out?!? Only reason I think this is there really is no indication that there is water in the oil. I have NOT found any tan/white stuff anywhere in the oil, nor under the cap or on the dipstick.
 
88gmctruck said:
I just had another thought.

Does anyone think that it would be at all possible that the PO was running a cheap oil, and this is the result of years of buildup of it. I ran Shell Rotella T, which i know is a detergent oil. Maybe it started to break the sludge out?!? Only reason I think this is there really is no indication that there is water in the oil. I have NOT found any tan/white stuff anywhere in the oil, nor under the cap or on the dipstick.
Click to expand...
The engine I posted pics of had no milky oil. All the thick sludge. Look the fire rings on the head gaskets over with a magnifying glass. The blow outs aren't always easy to see. The wonderful tty bolts could have stretched on one cylinder[#8& #7 is suspect]. Was there a wide variance in torque of the head bolts?
Heads and decks should be checked for flat with a precession straight edge and feeler gauge.
 
If there is coolant in the oil that is likely the cause of the turbo bearings going.
 
bk95td said:
The engine I posted pics of had no milky oil. All the thick sludge. Look the fire rings on the head gaskets over with a magnifying glass. The blow outs aren't always easy to see. The wonderful tty bolts could have stretched on one cylinder[#8& #7 is suspect]. Was there a wide variance in torque of the head bolts?
Heads and decks should be checked for flat with a precession straight edge and feeler gauge.
Click to expand...
Devin pulled the head bolts, he said if by "insanely bejesus tight" then yes, they were all tight.

NVW said:
If there is coolant in the oil that is likely the cause of the turbo bearings going.
Click to expand...
Possibly. I did have the runaway PMD and I know the turbo overheated in that situation. Was just before the last oil change on 4/8
 
The cracks in the heads don't mean they are bad. See my k3500 thread. I had the same cracks and put the heads back on with new gaskets. the truck runs mint with no issues. As long as the cracks don't go into the valve seats.
 
That is what i'm hoping.

Having issued taking the turbo apart. The 13mm bolts are stubborn on the exhaust to intake housing. 3 of them you can't get a socket or box wrench on.
 
The head bolts were all very even as far as their tightness, it gets difficult to judge them by the time you're through all 34 of them (it is 17/ea, right?) I went through with a breaker bar and loosened them working from the ends to the middle, then switched to a ratchet and pulled all the bolts. It is nice being tall, I can stand at the front of the truck with my heels flat on the ground and reach the rearmost head bolts. :D

We're done for the evening now, before all light was gone I did another Superman impression on the front core support. I had my face inches from each cylinder, I did not see any cracks. I did find that #6 has scoring similar to #8. I wiped each cylinder down with WD-40 and a rag, turning the crank over by hand from the crank pulley, dropping the pistons down to the bottom of their stroke before I looked each over with one of David's ridiculously bright little LED flashlights.
 
88gmctruck said:
Oh, and IIRC you commented on my footwear when I was rebuilding the trailer last year. :p
Click to expand...

hmm, I sense a pattern here. Just some subtle advise from someone who use to wear the same footwear until I smashed the hell out of my foot once when I should have been wearing boots.
 
trouttrooper said:
hmm, I sense a pattern here. Just some subtle advise from someone who use to wear the same footwear until I smashed the hell out of my foot once when I should have been wearing boots.
Click to expand...
Yeah, I do know better it's just more comfortable at the time, being as i was sitting washing parts all day.

-------------

As Devin said, we can't see any apparent cracks in the cylinder bores. The only cracks we've found are the ones posted before, between the intake and exhaust valves in 3 locations.

Anyway, today the waterpump and rest of the cooling system came out. Every motor piece that came out has also been cleaned and inspected. Pressure washed the radiator and cleaned the crud out from between it and the condenser. Devin also spent a good chunk of the day fixing the 2 broken exhaust manifold bolts at the crossover flange. Also started to tear down the turbo, but 3 of the 5 13mm bolts holding the compressor and turbine housings together, because you can't get a box end on them. Left it soaking in PB for the night.

Only other "bad" thing found was 2 of the pushrods had some scrapes on them. Not sure why, but it's on the head side of the pushrods. Rockers all looked good except 1 that had a bit more wear on the spring side.

More gaskets come in tomorrow, going to re-install the waterpump and some of the cooling system.
 
I encountered the same issue with the GM8 turbo, tried PB Blaster a few times for a couple days and still could get it and rounded the corners on the bolts. Oh well, I didnt really have to get it apart, it was just curiosity for me.
 
88gmctruck said:
I just had another thought.

Does anyone think that it would be at all possible that the PO was running a cheap oil, and this is the result of years of buildup of it. I ran Shell Rotella T, which i know is a detergent oil. Maybe it started to break the sludge out?!? Only reason I think this is there really is no indication that there is water in the oil. I have NOT found any tan/white stuff anywhere in the oil, nor under the cap or on the dipstick.
Click to expand...

This is where you take a break from the project and let your mind sleep on it.

Then you look at the pictures of the water in the turbo intake and other signs of coolant in the oil and understand that it is happening and tearing down the engine is the right thing to do to find the leak.
The engine sitting overnight may allow the cracks to seep oil or coolant and show up better.
 
88gmctruck said:
That is what i'm hoping.

Having issued taking the turbo apart. The 13mm bolts are stubborn on the exhaust to intake housing. 3 of them you can't get a socket or box wrench on.
Click to expand...

The first time I took my turbo apart I had a couple that I had to grind the heads off . then find replacement bolts. I antisiezed it pretty good and when I took it apart the next time it wasn't too much of an issue.
 
You must log in or register to reply here.
Back
Top