oil in combustion chamber

bwilson · Post by **bwilson** » 19 Jan 2013, 09:58

I'm totally flumuxed. I have a 2000 S80 2.9 that has been sitting for a year. I went to start it and it would turn over but not start. I pulled the coil cover and there was oil on top the head. Then i pulled out a coil and the area was filled with oil to the top of the sparkplug! This was true on four of the six. Removal of plugs caused oil to drain back down into combustion chamber. Any thoughts anyone?

Post by **precopster** » 19 Jan 2013, 15:01

Replace the oil filler cap. Most of that oil is from a hardened leaking seal. You can buy the seal separately.

Personally I would have used as many shop rags to drain the spark plug holes before removing the spark plugs. You just don't know how much grit was mixed with that oil and this grit can seriously scratch the bores as it travels up and down with the piston's skirts.

To get through this you may need to poor some fuel down there to dilute the oil so it can run down the cylinders then change the oil as it will be contaminated. Clean and gap the plugs too.

bwilson · Post by **bwilson** » 19 Jan 2013, 17:42

Thanks precopster, but how would oil get in the chamber that houses the coil bottom and plug? The filler cap directs oil right to the valvetrain then to the oil pan. Your right about allowing the oil to drain into the cylinders, that was dumb, but I was so surprised at what I found and the quantity of oil in the chambers, that I just didn't think it through. I'm still perplexed.
Bob

Post by **precopster** » 19 Jan 2013, 19:15

If you follow the routing of ther machined ring around the oil filler cap you'll see that it evenually drains under the plastic covers and then out through a small hole in a plastic cap on the exhaust side of the cam cover.

The small hole gets blocked and all the oil ends up going down the coil pack holes (and in your case down into the combustion chamber) The coil packs are not a perfect seal and this is why oil ends up down there. A VERY common whiteblock problem solved by a $2 seal.

The other problem is the seal b/w cam cover and head. Of the 46 bolts holding the cover down are any of them stripped?

bwilson · Post by **bwilson** » 20 Jan 2013, 13:02

Thanks precopster, i never imagined that could be the case but i'll drain the oilpan, clean the plugs, and see if she will start. Thanks again for putting me on the right track.

Post by **precopster** » 20 Jan 2013, 14:39

Read somewhere last night that excessive pressure in the PCV system can also force the PCV hose on top of the engine to leak.

After you clean it out leave the covers off so you can see if there's any further leaking.