Oil Soaked Spark Plug

Geico266 · #1 07-28-2012, 06:49 PM

Doing a compression check this am on my Aerosport IO-540, the #5 cylinder, lower spark plug was covered in oil. Oil consumption is around a quart every 8-10 hours. The plug is just wet, not black and carboned up. Mag check is fine so it is firing.

Any ideas?

Geico266 · #2 07-29-2012, 02:08 PM

Another forum provided the answer.

dmaib · #3 07-29-2012, 02:14 PM

I have a similar situation with one cylinder. What was the answer you got?

Geico266 · #4 07-29-2012, 02:32 PM

Quote:

Originally Posted by dmaib

I have a similar situation with one cylinder. What was the answer you got?

Oil wiper ring is weak. It can be replaced by pulling the cylinder part way and replacing just that ring, but since the oil consumption is low, and the spark plug is not fouling I was advised just to monitor it. Compression on # 5 been consistently 78 / 80.

I have 600 hours and 6 years on the rebuilt engine from Aerosport. The engine has been flawless except for this minor issue.

I may pull the cylinder and replace it just for something to do this winter. Can't be that big of deal.

dmaib · #5 07-29-2012, 07:08 PM

Very similar situation. Good compression, plug (fine wire) is performing fine, but my oil consumption is higher than yours. 1 qt every 6-7 hours. So, am figuring that cylinder is going to have to come off one of these days.

Geico266 · #6 07-29-2012, 07:57 PM

Quote:

Originally Posted by dmaib

Very similar situation. Good compression, plug (fine wire) is performing fine, but my oil consumption is higher than yours. 1 qt every 6-7 hours. So, am figuring that cylinder is going to have to come off one of these days.

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