I have a '98 z28 with an '01 Ls1 motor swap, recently I noticed that when I fill up the oil to exact measurements, I'll see tons of blue-ish gray smoke out the exhuast when it's fully warmed up and when it's WOT. It wont smoke at idle when its cold or when it has a certain amount of oil in the engine. I installed an oil catch can and didn't seem to help at all.

Haven't gotten around to doing a pressure test.

motor has 130k miles and I use 10w-40.

I feel no loss in power or response from engine.

cranks 1 time every start.

eats 1 quart every 100 miles or so.

no coolant leaks or head gasket problems.

help.....

 

I once had a similar situation with an Oldsmobile 350 that turned out to be valve guide seals. My situation was so extreme that it would foul the back sparkplugs, so that made it obvious. Have you checked your plugs?

 

i replaced 2 cuz the previous owner was too lazy to do cylinder 8 and that spark plug was burned clean. Cylinder 5 had one where it was reading a misfire and I replaced the spark plug, that one was covered with oil and or soot.

 

#5 it is. Sounds like you have your culprit. that being said, I would check all guides/seals anyway.

 

Are you sure you aren't overfilling the oil? You might have a wrong dipstick. How much oil goes in after an oil and filter change?

 

I've been thinking the same thing too. I'll check with my parts guy too to compare oems and the one I currently have.

 

Valve seals don't cause 1 qt every 100 miles usage. Pull all the plugs and find the oily one, replace that cracked-burnt-melted damaged piston, no more oil usage.