Coolant & Oil = BAD

[Ray Sharpe]

I recently had the oil tested on my '99 truck because I was loosing Anti-freeze. (about 3 qts per 1500 miles) The tests came back with a big NEEDS IMMEDIATE ATTENTION label on the top. Turns out that the Anti-freeze is going into the oil and that it is taking out my crank bearings. The engine doesn't smoke, and it seems to run fine. But I don't know how to start diagnosing the problem. My buddy recently did the head gasket on his '93 6.5TD because it was bubbling in the overflow bottle. My truck doesn't do this, so I don't know where to start looking without tearing the motor completely apart. Any ideas would be appreciated Thankyou.

[Dvldog 8793]

Howdy
Just went through the same problem, do a search for coolant loss and appetite for antifreeze.
Sounds like you will end up taking the engine out for a cracked block. Those are the exact symptoms that I had. The new orange antifreeze mixes with oil and turns to sludge. Check the inside of the PCV valve for this black jelly stuff. Depending on mileage GM may warrenty it. They covered 30% of my parts when I was 50k miles out of warrenty. Good luck!
L8r
Conley Janssen
USMC 87-93

[Ray Sharpe]

I am hoping that my block isn't cracked. My truck has 128k miles on it, do you think that might still cover some parts?

[Dvldog 8793]

Howdy
Go through the GM customer service dept for a claim startup. I diagnosed the problem with mine by pressure testing the coolant system cold then finding the water in the oil. Since my truck was way out of warrenty I never thought to take it to the dealer. I had to bring my block in and the dealer looked at it and then backed me up with GM. That was probably the key in me getting any money from GM, my dealer backing me up 100%.
I think the majority of people told me that to try to tear it down "in frame" would be an exercise in frustration. After removing the engine and putting in a new AMG long block I would say it was fairly easy but time consuming, also it gave me a chance to check other things that normally go without.
Hope this helps !
L8r
Conley Janssen
USMC 87-93

[Ray Sharpe]

That sounds interesting. But do you think I should take it to the dealer for them to diagnose? I have already pressure tested the coolant system and it held 15psi for half an hour without loosing any pressure. I also pressure tested the rad cap, and it was good as well. I've been told to check the gasket on the water pump and also to see that the weep hole on the pump isn't plugged, but all that seems like a big PITA if I ultimately find out the block is cracked. Thanks for the info and keep it coming, everything is appreciated. Thanks

[Dvldog 8793]

Howdy
My truck sucked up 2 gallons in 200miles w/ no increase in oil level. I pressure tested to "normal" levels and had no drop. I then took it to 16.5 psi for about 4hrs. Then I had about 1-2psi drop. I then VERY slowly cracked open the drain plug and the first slow drop to eek past the threads was water. :mad: Then I started to remove the motor. Almost everyone I talked to said that IF I couldn't find an external leak and there was no bubles in the coolant then it would be a cracked block. Did you check for oil jelly in the PCV valve/tube?
Conley

[Ray Sharpe]

I'm going to re-test the system again with the higher pressure. I'm also going to check that PCV tube like you say. I'm going to check everything that I can before I start to yank out the motor. Thanks again.

[Ray Sharpe]

I just checked the PCV tube and it is caked with black goop. Things are looking gloomy.

[jspringator]

Would in be worthwhile to put a stud girdle on a late 99 (build date 8-99) with 175,000 miles? No antifreeze use yet. At first I was terrified that this would strand me on vacation, but, on reflection, this problem would at least let me make it home, even if I had to change the oil a couple of times.

[Dvldog 8793]

Howdy
I had a SEVERE crack in the number 4 web that extended into the cylinder walls of #6 & 8 about 2.5 inches. The crack didn't make it into the combustion chamber but I would think that if it did BAD things would happen QUICKLY. :eek:
I've been told that one of the new features of that orange antifreeze is extended run time with contaminated oil??? Who knows? I know that the old green stuff would make scrap out of bearings fast. I purchased a stud girdle and then sold it new after I talked to experts and determined that the new blocks are WAY better. AM General blocks that is. If you were going to tear down and rebuild a motor I think I would go with a older block that never cracked and then machine it for splayed main caps. My block shifted in the crack about 1/32 inch with cap bolted in place! when I priced my block I went with a AM General Navistar long block from GM. It was the mist expensive but also had the best warrenty and was VERY complete and had been pressure tested. In the end it didn't cost me anymore than the next runner up in price as GM stood behind 30% of the cost.
L8r
Conley Janssen

[Ray Sharpe]

Hey guys, thanks for all the info. One silly thing that I've been kicking myself for since this all began is that my girlfriend bought me the stud girdle kit for my birthday back in june. Maybe would have stopped the cracks from forming.(If indeed I do have a cracked block) Also, could you seen the cracks in the block simply by taking off the oil pan without dismantling the motor? This would be a relatively simple task. I pressure tested the engine this morning, pressure dropped from 18-12 psi in about 40mins. But the engine was hot from driving to work so maybe some loss was due to the engine cooling down. Thanks for the info. L8R

[Dvldog 8793]

My 6yr old daughter looked at the motor when I took off the pan and said "theres the crack!"
VERY large and obviouse, visiable from about 10 feet.
L8r
Conley

[Uncle Wally]

Dvldog,

Remember me? <<laughes>>

You still have that rotating assembly from yer cracked block?

Thanks,
Waldo

[Ray Sharpe]

I'm going to pull the pan off in the next few days. Can the pan be pulled without removing the front diff? I assume that it would probably be almost as easy to pull out the diff than to try to get the pan in and out without filling it with dirt with the diff in.

[Dvldog 8793]

If you pull the pan, the main place to look for cracks is the inside block webs. Mine was VERY obviouse. If you decide to pull the motor let me know and I can give you some hints. Can't help with the diff question as I've never had to do one. yet...............

[Ray Sharpe]

I pulled the pan off my truck today at work, and NO CRACKS. smile.gif Now its on to the heads. Now that I've had to take the front diff out, it gives me a reason to put new axle seals in it. I've been meaning to do this for a while anyway.

[jspringator]

Did you put on the stud girdle while you had the pan off? You may have lucked out!

[Ray Sharpe]

No, I didn't put the stud girdle on yet. When I sent the oil sample away it said that the coolant had started to eat at the bearings so I'm going to install the girdle kit when I yank the motor to do the bearings.