Hello-

The car is a 91 Civic STD 4 speed. It has high mileage on it (maybe 150k)

Recently, the car wouldnt idle so we inspected the plugs to find oil caked over one of the sparkplug electrodes.

There was no oil on the top part of the sparkplug, only the part within the compression chamber.

Is this evident of stem seals, headgasket, or maybe piston rings? I am under the impression is isnt a VC gasket because there was no oil on the top part of the plug.

Any help would be appreciated, I am advising my friend on his '91 from a few states away so I cannot go check myself.

Thanks!

 

Try dry/wet compression tests.. Could be a bad valve seals.

 

Thanks for the advice! Like I mentioned before, I am asking for a friend who happens to live a few states away

I could easily do a leakdown test bit I feel it may be a bit tough for him to do over the phone. He has a haynes manual and doesnt mind breaking the car (hes mainly doing this as a learning experience)

Any other advice?

I will ask him what his opinions are on the leakdown test. (also, what is the difference between wet and dry leakdown test?)