Hey guys.... 1st post/thread of (hopefully) many!

Anyway, I bought a 96' C1500 with a 5.7 (350) with, what the owner said has a blown headgasket.

It was VERY cheap, so I bought it thinking it would be a good truck after the fix.

Anyway, here's my trouble. The oil is pure sludge. Coolant in the oil. Truck starts and "runs" (very low power), but otherwise feels good.

I just drained the oil, and got over 2.5 gallons of sludge out.

Then I did a compression test, and they are all within 15% of each other. 180 for the high, and 150 for the low.... I'm starting to wonder about the head gasket.... Can they leak water/oil, and not affect the combustion chamber? (seems hard to believe to me)

The truck has an oil cooler .... is it possible the engine is ok, and just the radiator is trash?

I also drained the coolant, but only got about a quart out (all the coolant is in the crankcase).

Yet another thinker.... The guy I bought it from just had a bunch of things done to it at a professional shop (and by "just done" I mean I bought the truck from him in the parking lot of this shop). Tune up, new batteries, alternator, and both upper and lower RADIATOR HOSES!! Any chance the shop either F'ed up the radiator/oil cooler... or did something on purpose in hopes the guy would spend more money??

Why he didn't sue the shop, I don't know, but I got a truck in great condition (other than the engine) for $600.

Sorry for the long post, but your help is greatly appreciated!!

Thanks,
Mark

 

Hi Mark,

Welcome to the Chevy Forums.

Why not fill the radiator with water, and see if it leaks out the cooling line holes?

Wouldn't cost ya much...

 

OK, updates:

Its not the radiator (well, not as far as I can tell right now)

When I try to fill up the radiator, the crankcase fills up as well.

Not slowly either. I can fill the radiator, then 30sec later, I can dump in another gallon of water to fill the radiator.... then again, 30 sec later, I can add another gallon to fill the radiator.

Before I go ripping into the engine, are we thinking head gaskets, cracked/ leaking intake, cracked block?.... It would have to be something that could leak water very quickly.

Thanks,
Mark

 

try this. empty the water from the motor and radiator. remove the lower hose. cap it off with something on both sides. so like a sock in the pump and radiator. then you isolated the top part of teh motor. fill the radiator up and see if theres water flowing into the motor. if so, then just to be sure do the same with the upper hose and remove the caps from the lower and place at the upper. repeat teh filling. then it gives you a better idea where the fluid is flowing into. id also invest in an oil pump primer so that when you do get this puppy all figured out and you re-fill that motor with oil, you prime that sucker.

 

You'll have to disconnect the oil cooler lines to figure out if the leak is in the engine or the cooler. If it's water out of the engine, you've localized it to the engine. If water comes out of the cooler, you need a new radiator.(IMO, the more preferable of the two.)

 

I did disconnect oil lines from the radiator. No water from there.

Its defiantly a big hole in the engine somewhere. I'm betting on the plastic intake.

I'll try to find it again, but maybe you guys can confirm it (or tell me I'm crazy)....

Wasn't there a recall on the plastic intakes on the 96-98 vehicles with the 5.7? I thought I read that somewhere.... Didn't Chevy have problems with them cracking?

It takes water as fast as I can pour it in.... gallons, right into the crank case. No gasket leaks that much. I could install the intake with no gasket at all, and it wouldn't leak that much. Something HAS to be cracked.