szalkerous

iTrader: (1)

So my 99 Z28 has been sitting for a few years while I slowly do some major suspension, transmission, and exhaust work to it.

The other day before putting in the headers I decided to nix the plugs and put fresh ones in since it was easy to get to. I noticed the two cylinders on the driver side, frontmost and rearmost, had oil on the spark plug threads.

This car wasn't eating any significant oil or producing any exhaust smoke when it was parked in the garage.

My gut reaction is blow-by on the rings, but how would those have fouled if the car wasn't run? I did drop the oil pan to remove a stuck dipstick and install a new pan gasket as it had seemed to start leaking... could the oil leak have been from elsewhere? If so, how would that have gotten into the combustion chamber?

I don't have the facility or the time to drop the entire subframe out for a ring job, and I intend to try and ditch this stock LS1 for an LS3 in the next couple years. Thoughts?

svede1212

iTrader: (3)

Could be valve seals. Blow by gets sucked back into the intake so it's possible although I'd open the throttle blade and see how much oil is in the intake manifold. Blow-by can be helped with a good coalescing oil catch can. Bad valve seals would need new valve seals.

szalkerous

iTrader: (1)

Valve seals would be just as bad, as I really don't want to pull the motor. I guess I'll have to fire it up eventually and monitor.

Although a $7k crate motor LS3 and the additional labor to prep it for a Gen III computer, install, and tune is a small fortune I really wasn't in the position to do just yet... Especially as I'm trying to save up for a new ZL1 down payment.

patSS/00

iTrader: (6)

When I took plugs out for replacing rockers, I found #7 had oil on the threads. I found that the rubber plug in the valve cover for the hole where the stock PCV hose used to go, had been leaking oil, and the oil had been running down to the #7 plug. The plug was not loose. So, an oil leak from the VC can run down the plug threads, that's something to check.

szalkerous

iTrader: (1)

Interesting. I hate the stock valve covers, so maybe I'll swap them off and get new VC gaskets in there.

Do aftermarket covers fit both LS1 and LS3 heads? I'll have to poke around. I'm trying to avoid investing too much money into a motor I'll be ditching for (hopefully) an LS3-480 crate motor. Just realized one can be had through Summit for under $6k after rebate.

dailydriver

^^^Yes, but then you are stuck with the bottom end rebuild on a BRAND NEW engine for the 24T reluctor option (as you alluded to in your second post in this thread), OR, 'taking your chances' with the Lingenfelter conversion box set up.

I HATE GM for not offering these LS3 crates with a 24T reluctor crank option, and ALL of the other crap to make them work in an LS1 4th gen.