Intake oil?

[cobra132]

I pulled the intake off my engine and found oil coating the secondary intakes, on the gaskets and about 2 oz in the valley. See photos. Engine was running fine. I suspect the valve seals are bad although this VT engine only has about 50 race hours on it. Thoughts? FMR

[silversvo]

I would have to say the valve seals are bad. I dont know why it would happen with only 50 race hours on the motor though. :?:

[GlennCMC70]

i disagree.
where is the PCV vented to? the LS1 engine was notorious for this. it vents the crankcase vapors thru the T/B so the engine can burn it. high revs along w/ high G's and you will get alot of oil in the valve cover and into the intake. try venting the crankcase to a catch can. the other fix is larger PCV tube size. a larger volume line will have less velocity for the same given volume of displacement. likely this will have little effect. bes to vent it to a can.

[silversvo]

I would have to agree with you Glenn as I assumed that it would have already been routed to a catch can.

[cobra132]

Both valve covers are vented into a can. All intake vacuum ports are sealed except the fuel pressure regulator line. There is no way for oil to get into the intake from above. FMR

[GlennCMC70]

so do the offending valves use a different valve seal than the others?

[AI#97]

VERY common. The motors pull a TON of vacuum and suck it past the valve stem seals... 4V's are worse than the 2V's and it is where most of the oil disappears to. That 97 Vert I had a while back had 1/2 quart in the bottom of the intake.

I wouldn't sweat it as what I saw in the pictures is fairly normal.

Going to be nice to get some cubes....I hope to build a new shortblock soon with similar displacement! Beware!!!!

[cobra132]

Valve stem seals should all be the same. If it is vacuum then why is there oil in the valley? FMR

[AI#97]

oil in the valley is probably leaking from a threaded port on the intake...Only way oil could get that high in the motor is to go up into the intake, pool in the plenum and then leak out. Might also be leaking at the cam cover gasket where the front cover meets the head....need a good bit of silicone there to keep it from leaking...

The intake I have on my car now sucks because the IAC motor is located on the bottom of the plenum. Probably why my car won't idle worth a damn cause it is drowning in oil...? I plan to disassemble the intake in the offseason and port it a bit. The cuts the manufacturer made look like a blind monkey worked on it... :evil: