I had my plugs changed and my mechanic told me there was a tiny bit of oil around them. He said it was the beginnings of something (gasket) but that I shouldn't worry about it. My car is still under waranty and I will tell them about what he found. Any ideas?

mb

 

Oil around the plugs is not always indicative of bad rings or valve seals, especially in a MCS engine. Oil tends to collect in the intercooler, boots and the rest of the intake tract because of the oily crankcase vapors collected by the PCV system. In most normally aspirated engines (MC included) the intake tract is smaller and there is little area for these vapors to settle out, they just get pulled into the cylinders and burned off. Intercooled engines by their design have long intake tracts which also function to cool the intake air. The slight downside to this is those oily vapors entering the intake tract via the PCV tend to condense and collect mostly in the intercooler. Periodically when the engine is running, and especially if you gas it harder after a long period of highway cruising or sitting in traffic, this oil gets flushed out suddenly, causing blue smoke out the exhaust and oily deposits in combustion chambers. If you remove the plugs after a long drive, you would likely not find any oil.

The primary fix for the oiling of the intercooler (which reduces it's efficiency) is adding an oil catch can.

 

I stand educated! Thank you.

mb

 

as I am

 

I haven't played with the MINI engine, but in the Miata when the valve cover gasket gets old, hard and leaks a bit, oil tends to collect at the base of the plugs as described above - assuming 'around them' means outside the combustion chamber. Given that both have plugs down deep in the valve cover, that could be what the mechanic is referring to. If that's what it is, it's not a big deal.

 

Damn GB. that was one helluva post.

Can I sign up for your shadetree mechanics course?