Oil puff on startup/stall - valve seals?

[mfergel]

So, my car has been doing something weird lately. About 75% of the time, when I start it up, as soon as the initial startup idle starts to come down it wants to stall and I'll have to pump the throttle to keep it running and an oil cloud will come out. This happens a lot when I park in my deck at work, which is at an angle (so the car leans to the side slightly). I'm almost thinking that oil is getting in the cylinder, possibly when I shut it off, and then when I go back to start it back up it's having difficulty running because the oil in the cylinder(s) is giving me an improper fuel/air mix. Both of my exhaust tips seem to be a bit on the dark side.

Any ideas?

 

[JUSTA3V]

Black soot is usually from over fueling. Or a rich condition

If it puffs blue smoke. That's oil. Could be seals and or valve stems. Those are the usual suspects for burning oil.

Also could be the rings but usually blows blue all the time if it's rings

You can pull the intake and visually look down the intake runner to see if there is oil pooling around closed intake valves.

Compression and leak down test time.

 

[46addict]

When you say the idle dips down and you have to blip the throttle, it sounds like a tune related issue. If the C&L intake is only engine mod you have and you have a stock intake to try, put that on and see what it does on the stock tune.

Also inspect all vacuum hoses, all connections on the intake, MAF insert and make sure none are leaking. Check for oil pooling in the throttle body and it would be a good time to clean the MAF & TB.

 

[mfergel]

Black soot is usually from over fueling. Or a rich condition

If it puffs blue smoke. That's oil. Could be seals and or valve stems. Those are the usual suspects for burning oil.

Also could be the rings but usually blows blue all the time if it's rings

You can pull the intake and visually look down the intake runner to see if there is oil pooling around closed intake valves.

Compression and leak down test time.

Yeah, definitely blue puff but dark black on the exhaust tips. Also seems to be going through a bit of oil so pretty certain it's oil. I'll add that I'm at about 140,000 miles. Not sure what the average life span is for valve seals/stems. Should I be able to see down well enough without removing the throttle body?

Good idea for a compression test. I haven't pulled plugs to see if any of them look like one or more cylinders might have a leak issue.

When you say the idle dips down and you have to blip the throttle, it sounds like a tune related issue. If the C&L intake is only engine mod you have and you have a stock intake to try, put that on and see what it does on the stock tune.

Also inspect all vacuum hoses, all connections on the intake, MAF insert and make sure none are leaking. Check for oil pooling in the throttle body and it would be a good time to clean the MAF & TB.

I'll double check all of that. I did do a reinstall of my tune just to make certain. I think the idle down issue is that at startup there just isn't enough air/fuel with the addition of oil to keep it going. Once it gets past that it stays running with no issues.

 

[46addict]

Too rich of a mixture could choke the engine too, and if your exhaust tips are darker than usual it's another sign of being rich. But if it's blue smoke it's definitely oil. I would follow what Justa3V said. There's no way to inspect valve stems without taking the head off. What do the spark plugs look like? Any oil on the threads?

 

[BullittSS]

I had a 2009 Bullitt that had an occasional puff of blue smoke on start-up, and used a quart of oil about every 1,500 miles. At 56,285 miles a valve spring broke, leading to a bent valve stem. You can read the whole story at:

http://www.imboc.com/forums/226-08-09-mechanical-issues/242938-broken-exhaust-valve-spring.html

 

[nawagner]

So just to check the boxes on the simple stuff. Rough idle could be dirty MAF or throttle body. Make sure they are clean to be sure you're dealing with the real problem.

 

[mfergel]

I'll check these things out this weekend. Thanks.