Oil on left side plugs

[benyflyguy]

Our club 182H is an annual inspection now. I stopped in just to see how it was doing. They said everything was going well but they noticed The spark plugs on the left cylinders (O-470) had oil on them. The compressions were all good. We recently did change oil to Aero shell 100 at the last oil change. The engine doesn’t really consume a lot of oil in fact during the summer run it consume less than I thought was usual. The mechanic said he didn’t really have a lot of concerns about it and that he was in a get everything changed and run it for a few hours and re-check the compressions. The engine only has about 300 hours on it. I admit I am out of my league when it’s talking about these things however it certainly sounded concerning to me?

 

[Clip4]

Are you saying both the top and bottom plugs on the left side were fowled with oil?

 

[ktup-flyer]

Mine has about the same time on it and consumes zero oil

 

[benyflyguy]

Are you saying both the top and bottom plugs on the left side were fowled with oil?

I will have to get more details. I was in a bit of a rush and don’t think I asked enough questions. I have time on Friday to head up and will ask more questions.

 

[Landing Fees]

May or not be helpful but you can expect a little more oil on the bottom plugs, usually. Should be cleaned at annual. All will look a bit different.

 

[Let'sgoflying!]

could an intake leak on the other side make them burn leaner & cleaner than the 'wet' side?

 

[Landing Fees]

could an intake leak on the other side make them burn leaner & cleaner than the 'wet' side?

Or the rings are not seated on the wet side. You have to take everything all together. We have a probable intake leak on #1 so the far right of the picture and it appears to burn clean. In cruise #4 burns hottest and there is a bit of oil on both. This engine is beyond TBO with 78/80 compressions but we fly often and most of the time in cruise. Every time I try to ask about the (perceived) induction leak in #1 our IA says it is a design flaw with the “spider” intake manifold. I even study the EGT/CHTs thanks to our JPI830 which gives me way too much information.

The 470 has top and bottom plugs like the 540, right?

 

[benyflyguy]

So they think it possibly from just overfilling oil. Some like to keep it 11-12 qts and they are suggesting keep it closer to 10 qts.
They want to button it back up and put an hour or two on prop and then recheck the compressions.
They did not discount the possibility of a ln intake leak though.

 

[Landing Fees]

So they think it possibly from just overfilling oil. Some like to keep it 11-12 qts and they are suggesting keep it closer to 10 qts.
They want to button it back up and put an hour or two on prop and then recheck the compressions.
They did not discount the possibility of a ln intake leak though.

Interesting. Too much oil and it could foul plugs? First time I heard that. It is true that planes typically have a happy oil level. It is hard to gather data with so many pilots flying the plane.

 

[benyflyguy]

Interesting. Too much oil and it could foul plugs? First time I heard that. It is true that planes typically have a happy oil level. It is hard to gather data with so many pilots flying the plane.

Will keep posted. I am curious and hopeful it’s not a big deal but always worried. The mechanic didn’t seem that concerned.