I have a IO540 with about 500hrs since overhaul that is leaking oil past the cam style dipstick cap. This has been occurring since rebuild contributing to a combined consumption/loss of about .2 qts per hour. My compressions are all 70+ when tested hot. I am seeing a little oil on the lower #1 spark plug but not enough to cause fouling. Also recently - (Jun/Jul time frame) I have noticed that my #1 CHT is running 18F less then the next lowest cylinder (#3).
I installed a slime beater in the breather line about 300 hours ago but haven’t seen any significant change to the consumption before or after.
Recently I used some dye to trace the leak and again found it coming from around the dip stick - I replaced the o-ring with a new lycoming dip stick o-ring from Aircraft Spruce and still am getting leakage past. I have doubled checked the cap is not lifting - oil is pushing past the o-ring.
My initial guess is I am getting excess pressure in the crank case from Cylinder #1.
My plan is to try to clean any gunk from the rings using a solvent sprayed in through the spark plug holes during my next oil change.
My other though was to try to check case pressure -but hate to destroy a oil cap.
I also was thinking about switching to a screw on cap to see if I start losing oil through the breather - still not sure why I am getting oil past the cap instead of through the breather - Yes I check it is unobstructed at least outside the case.
Lastly I though I would share my oil level - I typically run 7 QTS and refill when it hits 6 QTS.
Any other suggestions or recommendations.
Thanks
I installed a slime beater in the breather line about 300 hours ago but haven’t seen any significant change to the consumption before or after.
Recently I used some dye to trace the leak and again found it coming from around the dip stick - I replaced the o-ring with a new lycoming dip stick o-ring from Aircraft Spruce and still am getting leakage past. I have doubled checked the cap is not lifting - oil is pushing past the o-ring.
My initial guess is I am getting excess pressure in the crank case from Cylinder #1.
My plan is to try to clean any gunk from the rings using a solvent sprayed in through the spark plug holes during my next oil change.
My other though was to try to check case pressure -but hate to destroy a oil cap.
I also was thinking about switching to a screw on cap to see if I start losing oil through the breather - still not sure why I am getting oil past the cap instead of through the breather - Yes I check it is unobstructed at least outside the case.
Lastly I though I would share my oil level - I typically run 7 QTS and refill when it hits 6 QTS.
Any other suggestions or recommendations.
Thanks