1991camaro1996

I have a 1991 Camaro with the 305 tbi v8. It has 220,000 miles on it, but I tend to think its been rebuilt at some point.
When i bought it, it was burning coolant, so I replaced the head gaskets and the intake manifold gaskets. When I had the heads off, there was no evidence of a cylinder burning coolant; no cylinder was exceptionally clean, and all the cylinders had a slight ring of carbon around the rim. The old gaskets looked fine, and there was no rust or deterioration on the cylinder deck or the cylinder head deck. Both surfaces where flat, and there where no cracks that i could find. The only sign of deterioration was on the intake manifold mating surfaces on the head and intake around the coolant crossover pasages (on both sides). But there was no coolant in the oil that i could tell nor was there any vacuum in the crankcase. I put it all back together and it still seems to burn coolant, so my question is, is there any way the coolant could leak into the intake passages without getting into the oil? Are there any telltale signs of a cylinder coolant leak vs a non cylinder coolant leak?
I believe it's still leaking coolant, because even after a half hour of idling, it will still make my hand damp, and it still has that coolant smell in the exhaust.

I've been driving my truck instead of risking ruining the engine in the Camaro, and i'd like to drive the Camaro a few times before winter comes, so any ideas, stabs in the dark, long shots, ect... are welcome.

Thanks.

mlbinseattle

If, in fact, it's coolant that's burning, then it means a leaky head gasket, cracked head, or cracked cylinder wall. Have you done a compression check on each cylinder? That should point you to where the problem cylinder(s) are. IMO, anything that allows coolant into the cylinder will allow the gas mixture to get forced out under compression.

TBRays98

Im assuming you think the coolant is burning bc you dont smell it or ever see it on the floor. But sometimes the simplest reason for this can just be from a bad radiator cap allowing the coolant vapor out. Check that first before you start breaking down the motor.

1991camaro1996

Yeah, i did a compression test before i did the head gasket and the highest was 180, and the lowest was 169, with the rest of them being around 172 or so, which confused me further. And i do smell it burning, especially around the taipipes, i wish it was my radiator cap, but i tend to think not.

hdis2002

iTrader: (1)

Since you say you can smell it burning, this probably isn't your issue. I too had a problem with disappering coolant. During the course of working on the engine I had replaced the head gaskets, radiator, hoses, etc. Coolant loss was slowly getting worse. Never could find it until one morning I left it running longer than usual to warm up. Noticed a substantial pool of coolant under the car. Opened the hood and coolant was pouring out of the heater control valve. The plastic case had cracked. It didn't leak until the car got up to temp and the system pressurized which usually happened when I was driving down the road.

Steve

1991camaro1996

It overheated the other day when I revved it to 2500 rpm for a couple minutes or so. Is that normal? I feel like it's not.