The car has less than 40K miles on it. About 6K miles ago, the previous owner replaced all the valves as the stem ends weren't properly hardened from the factory, and were worn and couldn't be adjusted properly. At that time, the engine did not smoke. I bought it about 4K miles ago, and it was smoking a little from the #2 pipe (when looking from the rear). It has gotten progressively worse.
I am expecting a problem with cylinders 10, 11, and/or 12, based on the exhaust pipe that is smoking. Last weekend, I took all the driver's side spark plugs out to compare them, and they all look uniformly tan. None of the plugs were black or oily to indiciate which cylinder is burning oil.
Here are the plugs, in order from 12 to 7:
![Image](http://i370.photobucket.com/albums/oo143/Heatmiser500/PhotoDec2813200PM.jpg)
Here's a close-up of 12, 11, and 10:
![Image](http://i370.photobucket.com/albums/oo143/Heatmiser500/PhotoDec2813229PM.jpg)
Santa brought me a leakdown gauge for xmas, so I did a leakdown test on these 6 cylinders. 12, 10, 9, 8, and 7 all have a remarkable 2% to 2.5% leakage. #11 has this, too, for part of the piston travel! Somewhere near TDC, the leakage increases to ~18%!
What does this all mean? I DON'T KNOW - which is why I"m asking here! To me, it seems like #11 rings are ok since it can get a good seal for part of the stroke, so maybe there's carbon built up on the cylinder walls? If oil was getting past the rings, wouldn't the #11 spark plug be black?
So how does oil burn but not get on the plug? My speculation has always been that a stem seal has failed, which is plausible given the crap in today's gas. If an exhaust stem seal has failed, wouldn't oil possibly drip down the stem to the exhaust valve, and then burn on the way out the exhaust without even getting into the combustion chamber?
Any thoughts or things to try? Are there any treatments to fix the #11 issue? By the way, the car runs fantastic and I hate to sell it, but I've got too many cars that I don't pay enough attention to. My Daytona may be next.
![Sad :-(](./images/smilies/icon_sad.gif)
-steve