rahusband

hey everybody. hopefully somebody can help me out with a problem i've been having with my LT1 camaro. After i rebuilt the top end of my engine about a year and a half ago it ran great, that is for about 3 days. after that it got slugish and eventually almost stoped running completly. it sat for about a year before i pulled the engine out and apon further inspection found antifreeze in all 8 cylinders along with rust and what appeared to be mold. The head gaskets appeared to be intact and not damaged, the heads were preasure tested along with the intake manifold which both checked out. Now this was my first engine rebuild and i could have done something wrong but i'm havin a problem figuring out exactly what happened to my motor. Any suggestions would be appreciated

SS RRR

Did you drain the block before pulling the heads? If not, the coolant could've been from seperating the heads from the block, leaking coolant from the waterjackets into the cylinders. Mold and rust is not uncommon for an engine that's sat especially if it's an uncontrolled environment. Rust is most likey superficial and easy to clean up along with the mold with a wire brush.
The not running thing... what was done to the engine? The intake manifold was pressure tested? Is this a 1st gen LT-1?

rahusband

By the looks of things the anifreeze had been sitting where it was for a while, when i rebuilt it i changed the cam, rockers, pushrods, springs, and had the heads and intake ported. when it started running crappy the first thing i noticed was that the r's weren't climing as fast especially at low rpm's. a diagnostic showed that different cylinders were misfiring at different times, it also over heated but didn't warp the heads. eventually it just had no power at low rpm's and less that half at hi rpm's

rahusband

it's the factory LT1 out of a 97ss

SS RRR

And you still had the intake pressure tested? How? No coolant runs through the intake.
Did you ever check your plug wires when this occurred? Did you ever check your fuel pressure?
Once again... did you drain the block before taking the heads off?

Heatmaker

That coolant came from somewhere, and that was your heads, or moisture that built up while you had your engine down, maybe you didn't realize. Who knows.

DID YOU DRAIN THE BLOCK WHEN YOU REMOVED YOUR HEADS?

rahusband

no i didn't drain the block but some of the cylindres had like 2-3 inches of anifreeze in them along with rust rings above the liquid, thats why i thought it had been there for a while. someone told me to pressuse test the intake but maybe i misunderstood they did something though. the plug wires were fine however the optispark was changed in the process of my trying to figure out what was wrong twice. the fuel pressure was never tested but the regulator was no more than a few thousand miles old

SS1156

I know this may sound dumb, but what's the best way to drain the block?

Stl94LT1

Pull the block drain plug and/or the knock sensor.

Heatmaker

There's plugs on both sides, best to get them both like Stl94LT1 said. That way you can be sure all coolant is out. THe plug on the driverside, and the plug on the passengerside (knock sensor)

Stl94LT1

If the antifreeze has been in the cylinders for long, you may need a rebore. Antifreeze can be very corrosive.

rahusband

I'm actually the most concerned with how that much anifreeze got in the cylinders, i'm gettin ready to put the motor back together and i don't want the exact same thing to happen again so how did it happen originally?

rahusband

oh and i forgot to say that the head gaskets didn't appear to be blown either

Z95m6

did you put sealant on the head bolts?

rahusband

yes i did