This one has come up many times, and while I don’t fly behind a Conti engine, I am pretty sure my Lyco one will not indicate any abnormal oil temp in the event of an oil leak which is before the oil pump e.g. straight out of the drain point. Right up until the oil level gets below the scavenge hole, and then you will lose oil pressure and the temperature will not be of much relevance since there won’t be any oil going round the engine. A leak after the oil pump would reduce flow to the various bearings serviced by the oil gallery and their temperature would rise, manifesting itself in a higher oil temp.
But I agree with cross-checking instruments. The typical one is a duff EGT probe (had maybe 5 of those in 14 years) which can be safely ignored in certain situations.
Low oil pressure is a reason to start diverting. But monitor oil temperature. Don’t do anything drastic as long as it’s normal or low. What have you to gain by shutting down earlier?
(Both low, and engine sounding OK is possibly electric fault common to both.)
Heh, and what do you know, today, our Cirrus SR20 had a low oil pressure indication!
Went down to 28-29 PSI in a climb, triggered a low oil pressure warning. Temperatures, sound, RPM, all stayed the same.
Flight continued to destination (maintenance base).
Interestingly, pilot reported switching fuel tanks and turning fuel boost pump, rose the oil pressure….
I had a low oil pressure warning climbing out of a cold and unwelcoming airport. Indicated oil pressure and temperature remained completely normal and so I decided it was a an annunciator fault caused by a faulty switch and continued to my destination, where an engineer checked it out and concurred with my decision.
Later at the hotel, I Googled the problem and discovered an AD in Australia covering my make and model. The oil pressure switches had to be replaced because following failure due to a cracked diagraphm, oil would leak out and cascade down the engine, setting it on fire. I’d flown 2 hrs like that, although in my case no oil had leaked from the switch canister. Hmmm.
I had a few low oil pressures in the old Commander. Every time it was due to some carbon or crud keeping the Oil Pressure Relief Valve partly open. On older engines, where the oil gets dirty quicker, this is a very common problem.
I believe that many catastrophic engine failures in the TCM engine, one will find a recent top overhaul. There are two such incidents noted in the first post. One as a recent top overhaul and the other as thru bolt torque. The bearing ends up rotating, cutting oil off to the piston and rod and within a minute the rod goes thru the case. Mechanics are supposed to remove the thru bolts to remove the cylinder and then using shims re-torque the thru bolt to keep the crush on the bearings. Some don’t bother and a loss of the crush can result in a catastrophic engine failure. Also it is an easy mistake when torquing the hold down bolts, that the thru bolt is torqued to the same value. The actual requirements for the thru bolt is much higher and needs to be properly torqued on both sides.
