Seeking Advice on Diagnosing Oil Consumption

[cgzro]

That's very common. Most of those bolts will take a 1/4 turn every now and then. Have your mechanic go around the sump attach bolts and case 1/2 bolts and torque them down. Those things are worth checking every time you drop the cowl or change the oil.

[OntheNumbers]

That's very common. Most of those bolts will take a 1/4 turn every now and then. Have your mechanic go around the sump attach bolts and case 1/2 bolts and torque them down. Those things are worth checking every time you drop the cowl or change the oil.

I thought you could only torque down gasket-separated surfaces only so many times before the gaskets were compressed to the point they were no longer effective. True, I've never had this done in the 5+ years of owning the Cardinal and will talk to the mechanic about getting it done. Would be very nice to see this improved!

Thanks!

[cgzro]

[quote="OntheNumbers"][quote="cgzro"]That's very common. Most of those bolts will take a 1/4 turn every now and then. Have your mechanic go around the sump attach bolts and case 1/2 bolts and torque them down. Those things are worth checking every time you drop the cowl or change the oil.[/quote]

I thought you could only torque down gasket-separated surfaces only so many times before the gaskets were compressed to the point they were no longer effective. True, I've never had this done in the 5+ years of owning the Cardinal and will talk to the mechanic about getting it done. Would be very nice to see this improved!

Thanks![/quote]

Dependson the gasket and mating surface area but the bolts are not there primarily to stop oil leaks. If they are not torqued properly the loads are not distributed properly which is much worse.

The cork valve cover gaskets are bad in that the cover on a Lycoming has a very narrow mating surface, a few mm and it will cut the cork in 1/2 if you over tighten them.

[crazyaviator]

Most gasket materials will "seat" after 1-2 heat-cool cycles and will need to be retorqued ( important with a new engine ) Then, I would suggest no more than once a year to check for torque on all the nuts/bolts firewall forward. I would even go as far as checking the torque on the crankcase mating bolts/nuts which don't have a "gasket" within 10 hrs of assembly. Same goes with exhaust flange nuts,,,, some systems seem to be designed to leak ,,, others will go a thousand hours and never leak. With all exhaust flanges on cylinders, NEVER let a leak progress beyond a trace amount before rectification.

[OntheNumbers]

Most gasket materials will "seat" after 1-2 heat-cool cycles and will need to be retorqued ( important with a new engine ) Then, I would suggest no more than once a year to check for torque on all the nuts/bolts firewall forward. I would even go as far as checking the torque on the crankcase mating bolts/nuts which don't have a "gasket" within 10 hrs of assembly. Same goes with exhaust flange nuts,,,, some systems seem to be designed to leak ,,, others will go a thousand hours and never leak. With all exhaust flanges on cylinders, NEVER let a leak progress beyond a trace amount before rectification.

I was going to start a separate thread but since you mentioned the exhaust here - I noticed this while looking for the leaks. The brass spacer on Cyl #4's exhaust port appears to be warped and black soot is coating the cylinder cooling fins behind. The exhausts were removed and reinstalled at the annual in January so I assume those spacers were replaced. Only this one looks stressed. Anyhow CA, is this what you meant by your comment? Aside from CO leaking into the engine compartment is there any other reason why this is bad? Just curious, will get it looked at.

Thanks to all on this thread for your help - I've gained valuable knowledge about my plane and how to troubleshoot oil leaks, much appreciated!

[cgzro]

Never assume a new gasket was used:)

Those exhaust nuts need to be retorqued. If not you will soon be pulling the exhaust, redoing the mating surfaces and putting a new gasket in there.

That should be corrected because if the gasket burns out then you have a loose exhaust etc.. Very unpleasant.

[OntheNumbers]

Never assume a new gasket was used:)

Those exhaust nuts need to be retorqued. If not you will soon be pulling the exhaust, redoing the mating surfaces and putting a new gasket in there.

That should be corrected because if the gasket burns out then you have a loose exhaust etc.. Very unpleasant.

Cripes! Thanks, the plane is grounded until that's looked at!