Some oily spark plugs

[oharab]

My 540's been missing a bit, mainly when it starts, getting better as the engine warms up. There's also quite a bit of exhaust smoke when I start off, mainly white, but slightly blue. I changed the plugs to see if that helps.
The nearside bank were fine, but first 3 of the offside (nearest the water bottles) bank were very oily.
They weren't gunked with oil, it was still quite fresh, there was no soot and was on both ends of the affected plugs. There was a little oil gathering in the compartment where the coils are, but it wasn't swimming in it.

Looking around, I'm seeing phrases like "valve cover gaskets", "piston rings", "valve guide" and "head gaskets". These all sound scary and expensive. Are there any ways of finding out what the problem is, other than stripping it down?

I don't have much luck with these cars, as well as this, I just changed the starter motor & need to replace a full set of bushes & I've an intermittent tail light bulb failure to diagnose! Why couldn't I fall in love with cheap cars?

Ben

[colo525i]

If it is cold (say less than 40f/5c or so) the exhaust smoke is normal.(it is really just steam) The exhaust on these cars is long, so condensation builds up inside and takes a while to evaporate. Change the valve cover gaskets to get rid of that oil pooling near the spark plugs, pooling oil can ruin spark plugs. Piston rings, valve guides and head gaskets are expensive things, but try the cheap things that are certainly failed (the valve cover gasket) first.

[Dave M]

As "colo525i" stated, the valve cover gaskets should be changed as there are other potential problems associated with the leak. If bad enough on the one side, they may allow oil into the plug hole. The bluish smoke at start up could also be oil leaking down the valve stem onto the valve due to worn valve seals. When you start the car, the oil is allowed into the combustion chamber. I believe i've heard talk of other M60 owners having issues with vacuum hoses leading to running problems. Someone may chime in about the likely culprits (relatively smple fix).

Otherwise, some questions to ponder:

-Is the smoke only at start up or do you see it during normal driving? Under hard acceleration?

-If you wipe your finger on the inside of the tail pipe, does it get sooty? (your finger that is :p )

-Were the plugs oily after checking in the morning or after a drive? Are we sure its oil and not fuel? (leaky injectors)

-Does the car use oil between changes?

-Does the car use coolant between changes?

Answers to these may provide a hint to where the bluish smoke is coming from(if not a vacuum issue). You may want to do a compression test to determine whether the oily bank varies significantly from the other. Then, a wet compression test may help determine whether its valve related. Its a good test to do anyhow. Hopefully its something simple as I see your 540 only has 100k, but from my experience, blue smoke is not a great sign.

Anyhow, fill us in,

Dave M