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iTrader: (3)

Hey guys,

I have been battling a slight misfire problem that is more of an annoyance than anything else. In doing so, I pulled plugs one through six (I'm too lazy to pull 7 and 8), and I saw that all three driver side plugs had oil on them while the passenger side looked clean.

The valve cover gasket is good, and there's no oil on the head itself. The PCV line going to the intake manifold does look pretty bad with tons of oil residue on the outside, and when I pulled it off to look at it, I definitely got a nice coat of fresh oil on my hand. However, I don't see how that could be the problem when I'm getting oil on only one side. The throttlebody didn't have any oil in it, but I didn't get a good look at the intake manifold.

Any ideas? Could this be a bad head gasket? I mean, I don't see how it could be valve stem seals, rings, etc. I mean, what are the chances that three cylinders on the driver side would have a problem and three on the passenger side wouldn't?!

FlashLCD33

iTrader: (8)

Are you sure it's oil and not fuel? A bad 02 sensor could try to dump more fuel, which would cause a misfire and wet plugs. Been there, done that!

One side will usually show rich, and the other side will look a tad lean. PCM trying to compensate is my guess.

Gauge

iTrader: (3)

I will post pics tonight. Hopefully you'll be able to check my work. It looks like oil to me, but I could be wrong.

Gauge

iTrader: (3)

It occurs to me that I have a HUGE exhaust leak between the driver-side header and the Y-pipe. It's really epic-sounding. I wonder if that could be the cause of this.

FlashLCD33

iTrader: (8)

I can't really see how an exhaust manifold leak would put oil on the plugs?

F8L_LS1

iTrader: (5)

is the exhaust leak before or after the o2 sensor?

just like flashled said, it could be dumping fuel to compensate.
same thing happened to my buddies cobra.

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iTrader: (3)

I'm not saying that would cause oil. I'm saying that you might be right, and it could be fuel I'm seeing. If the leak is letting air into the exhaust and the O2 is reading it, then it must think the car is running too lean and just loading up that bank with fuel... thus causing the problem that you described.

The leak is after the O2 because the O2 is in the collector, and the leak is between the collector and the pipe... however, I've read several times before that the pulsing of the exhaust can actually allow air to get sucked in through a leak and actually pulled upstream to an O2 if it's in close proximity.

Do you guys agree that this is a possibility? Again, I'll have good pics up tonight.

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iTrader: (3)

Okay, here are the pictures. They're huge, so I'm only going to link to them rather than using IMG tags. First, the passenger side (which were clean):

Plug #2
Plug #4


And, now for the problematic ones:

Plug #1
Plug #3
Plug #5

FlashLCD33

iTrader: (8)

Not sure about the air getting sucked upstream, but it seems unlikely. You should fix that first and see if it does anything. If not, at least you won't hear the ticking any more

I'm not the best at reading plugs, but that looks a lot like fuel to me. Usually oil will leave more deposits because it doesn't burn off as easy.

Gauge

iTrader: (3)

I pulled #1 again today just to look at it in the sunlight, and it looked and smelled like oil. I'd really prefer to believe that it's fuel because the solution is more likely to be simple. Look at the picture of #5? That looks awful dark and thick to be fuel. Plus, wouldn't the fuel evaporate in short order after pulling the plug?

Anyone have any opinions about the plugs looking rich or lean?

AutomagicLS1

iTrader: (18)

I would do a compression test on the problem cylinders and a leakdown if you want to really want to get mad (if there is indeed a problem)

Gauge

iTrader: (3)

I spoke with my dad about this a bit, and he suggested that it could be bad valve stem seals. My first thought was that it couldn't be all of them on one side... However, I have had to change a few valves on that side, and I didn't change the seals at that time.

I noticed today that my car smoked on a cold start. There was no other oil smoke the rest of the day. That definitely looks like valve stem seals to me. My question now is this... could oil leak through the seal, down the stem, out from the seat, and then run along the top of the combustion chamber (rather than dripping down onto the piston) and then crawl up the threads of the plug? It sounds plausible to me, but has anyone ever seen oil on plugs due to valve stem seals?

98Camarod

iTrader: (43)

If it just smokes on start up then I would suggest valve seals.