Oil filter housing - relief mechanism failure.

[Alan Williams]

On my 76 p-model S/N 246 the rear engine oil fiter housing relief plug had come loose. We replaced that housing with a new continental part and about 10 hours later oil pressure dropped from 50 lbs to 32. Hmmmmm?
Cold pressure in the green, Operating temp gave 32 lbs or minimum spec. What to do then. Put on another twenty hours with no change to low oil pressure.
Then, R/E waste gate actuator began to act up masquerading as a fuel vapourization issue. At 16,000 ft manifold pressure dropped to 20 inches and returned to 28 in with descent . Purging of fuel system solved the problem for about two hours.
Finally after much pressure checking decided problem needed to be addressed. Engine was dissasembled. First off, the new oil filter housing. Oh Oh, look, the relif spring basket is hanging by two of its three legs and the fibre disk is GONE. Only one way for it to go but the question is how far. Found it jammed by the overhanging gasket at the entrance to left hand engine case gallery acting and looking like a butterfly valve in the hole. The oil pressure port is about 10 inches further along the case so now we know where the oil pressure went.
Was there any intermal damage to the engine. None at all.
However now we have a 900 hour factory reman engine which was running superbly and looking for all the world like it would go to TBO IN small pieces because a factory new part failed.
Question? Should the manufacturer bear some responsibility for the costs to reassemble.

[SkyKing]

Alan,

You ALREADY know the answer to your question, so get on it. Sorry to hear that quality control at TCM is down the tube.

BTW, what you will find in dealing with any of these outfits is that when they are pressed with product liability they will usually comes through to avoid litigation, but in taking care of parts, labor and what-have-you, they will ask that you sign a release in which you cannot even mention the settlement... this is one of the reasons why NOBODY ever hears of the success of going after these things, i.e., "my lips are sealed" because of contract law provisions. Just make sure that you get everything you ask for before you sign any kind of release. Nope, this is not legal advice, just counsel from a fellow pilot who has already been through the 'mill' with FBO's and component part vendors. Oh, and I am a former FBO too, so I know both sides of the fence. What surprises me is how everyday people just fold and go along to get along with the general aviation industry through AD's and other nonsense, that if you really search out, are in reality a defect in the manufacturing process. Sorry, I can't mention the one I want... remember, my lips are sealed... but can you say 'heater'?

SkyKing

[Alan Williams]

Skyking
Thankyou for your thoughts. I have not had experience with an aviation situation of this type so your comment re a release and non-disclosure clause are most helpfull.
The shop which dissasembled the engine has put in an SDR in Canada and I would certainly look at the unit if I had one. I understand there is an old service buletin which says one "may" take the spring disc assembly out, peen a plug disc solidly in place and run a bypass filter instead. Sounds like a very good "suggestion"to say the least.This is what had been done in the first housing which we had to replace as the plug had come adrift and was rattling around in the seat where it at least culd not do major damage other than cause limited filtering of the oil.
So, in conclusion I am leary of the peening a plug remedy as we have seen a failure of that also. You can not detect that failure without removing the filter housing which I dont think happens very often. Ours was off to fix a leak in somthing else. So, one will merrily look at the oil fiter thinking the engine is showing no wear when in reality you will have no indication what is going on till oil consumption changes dramatically or a more catastrophic failure occurs.
This needs to at least have a regular inspection time of some number of hours or a better fix.
I dont want to alarm anyone but if our engine had crapped out at 16,000 ft over the rocks in the clag with a full load it could have been an ugly situation.
Cheers
Alan