so I've narrowed my problems down, time for a new thread. I have a 94 Z28. I'm not sure if it ran before it was parked, but it had been sitting for almost a year. the motor was kinda hard to turn over at first, but seems to turn fine now. checked the compression, from front driver cylinder counter clockwise: 150psi, 60psi, 10psi, 0psi, 100psi, 0psi, 2psi didn't check the last one.. I'm not sure if it is leaking from bent valves now. I was told that the LT1 is a non interference engine. so it's not likely to have any bent valves. what could be causing my lack of compression?? has anyone had compression blowouts on a stock lt1 headgasket before??

 

bump...

 

If it sat for a while the rings could have stuck to the cylinder walls and snapped when you turned it over. Usually a good idea to take the spark plugs out and spray some sort of oil into the chambers and letting them sit for a bit before trying to turn it over. Especially if it's been sitting for a while.

I don't think a head gasket failure would cause that type of compression loss down to zero but I wouldn't rule it out.

 

I thought of that too, so today I poured a bunch of Marvel Mystery Oil into all of the cylinders and let it sit for abut an hour and a half.. I turned it over with no plugs in it, and I can pretty much account for all of it on my driveway. made no difference in compression, and I don't think any of it seeped passed the rings. if it was going to it would have in that amount of time. I think I can basically rule out bad rings or pistons. guess it's time to rip the heads off

 

Before taking the heads off, pull the valve covers and see how the valves are moving, and may try to adjust them.

 

I popped the valve covers off and everything seems to be working fine. I'm leaning towards blown head gaskets now tho. I pulled the radiator today, and there was no anti freeze in it at all. and there was a brand new thermostat still in the box in the car when I got it and the radiator fans were wired for constant on with key.. so I think it must have been having some overheating problems before I got it. the little bit of anti freeze that I got outta one of the connecting lines looks like it has some pastey clay looking crap in it. I was told thats what carbon deposits look like from compression leaks. any thoughts??.... I also drained the oil today, it didn't look all milky but it does smell like fuel really bad. probably from me bottle fueling it during all my testing

 

well I found my problem.. I've been tearing into it the past couple days to find a clearly detonated cylinder head. gonna see if I can go ahead and get them welded and machined for cheaper than a set of used ones. I'll pull the other head tomorrow and see how bad it is first tho..

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lol, tried to post a pic.. not sure it worked

http://i721.photobucket.com/albums/w.../burnthead.jpg

check it out there lol

 

Oh, those don't look so bad, you should be able to epoxy those pot holes!
Seriously tho, it looks like those spots were corroded through from the water jacket side.
That's a poster head for showing why you want to flush the cooling system frequently.

 

ya, idk maybe that is what did it. they're really not too bad tho. I got the other head off today, it was fine.. no cracks or anything like the other head lol. I called my machinist today, he has another shop that will be welding up the head and then he'll be finishing the work along with cleaning the other head and trueing everything. hopefully it'll all work out