Oil from exhaust pipe with RaJay TN

[M20F-1968]

I pulled the plane out a week ago to go flying and stopped at the pump and refueled.  Checked the weather again and decided to stay on the ground.  Taxied the plane back to the hangar and put it away.  0.1 hrs tach time from taxing.

When I came back to the hangar a week later, there as a 1" wide X 1.5 feet long oil stain coming from the exhaust.  This plane has a RaJay turbo-normalizer with check valves in the oil lines going to and from the turbo.  What are the odd that is is due to a check valve not closing completely and oil seeping from the turbo bearing (which really only seal when the turbo is running) as opposed to some other problem.  I plan on doing a good run-up to close to full temp.  Then stopping plane, looking outside for any more oil.  Should I be safe to fly?

John Breda

[StevenL757]

In your case?

1-800-Brian-Kendrick  ;-)

[LOCOLJ]

We had a similar situation and we found a turbo hose was leaking/loose at the fitting near the scavenge pump.   From what I understand,  we believe this was causing oil to pool at the turbo and made its way out the pipe.

[N201MKTurbo]

You are probably correct. It is a check valve. Take them apart and inspect them, it is either dirty or has a broken spring.

Not a safety of flight issue, they are just there to stop the mess.

[Guest]

8 hours ago, M20F-1968 said:

I pulled the plane out a week ago to go flying and stopped at the pump and refueled.  Checked the weather again and decided to stay on the ground.  Taxied the plane back to the hangar and put it away.  0.1 hrs tach time from taxing.

When I came back to the hangar a week later, there as a 1" wide X 1.5 feet long oil stain coming from the exhaust.  This plane has a RaJay turbo-normalizer with check valves in the oil lines going to and from the turbo.  What are the odd that is is due to a check valve not closing completely and oil seeping from the turbo bearing (which really only seal when the turbo is running) as opposed to some other problem.  I plan on doing a good run-up to close to full temp.  Then stopping plane, looking outside for any more oil.  Should I be safe to fly?

John Breda

My buddy’s twin Comanche does this once in a while.  Never been able to stop it or fix it, it doesn’t burn or leak when it’s running.

Clarence

[tomgo2]

I agree, probably the check valve. www.rajay.aero sells new ones.

RAJAY just certified new PMA replacement hoses for AD 81-19-04 which extends the life from 5 to 10 with plans to terminate the AD once more in-service results are collected.

[MarkM20C]

Mine does it too, drives me nuts. Doesn't use much oil in flight, but makes quite a mess when parked and on start up.  It seems to me the check valves should be at the turbo, so the oil in the lines between the check valves and the turbo can't drain into the turbo. On mine, the check valve on the return line is approx. 16 inches from the turbo, probably 10 inches from the turbo on the supply side. At some point I may move them closer, but I'll have to have new lines made at the same time.

[tomgo2]

Just an FYI...RAJAY now has PMA'd hoses to comply with AD 81-19-04. The FAA agreed to extend the RAJAY hose life to from 5 to 10 years to begin with and then make it a terminating action if we can provide in-service data to support it.