oil leak on 2.5 lux engine

[ian d]

i have developed an oil leak at the front end on my 2.5 ltr lux engine. oil across undertray. it is more noticable after a long run, not much oil lost driving round town. use 15/40 mineral, changed every 5k miles, engine done 74k miles.

anyone any experience of similar?
crankshaft front seal? i dread.
request a bit of info before i start taking things apart.

[timward]

had exactly the same problem on my 944 2.7. Undertray caught most of the oil so it didnt show up as a pool on the garage floor but the lower/front part of the engine was very sticky. I'm afraid a front end rebuild is a definite possibility, unless you can find an obvious leak from elsewhere. Usually the balance shaft seals just ooze gradually, rather than creating a major leak. My independent (Oak Tree Garage in Newton Poppleford, Devon) explained that with time small impurities and junk in the circulating oil grind down the balance shaft bearings/seals. He showed me one seal with a lovely set of shiny circular grooves round it. Cost me about £500 to get it done.

makes the case for a regular oil change though 944s are now so old that the damage will almost certainly have been done by now

Incidentally the OPC who had replaced the radiator the previous month failed to diagnose it, though they did steam clean the engine "because its covered in oil"!

sorry to be pessimistic, and hope I'm wrong!

[ian d]

thanks, doesn't leak much oil pottering round town but clearly oil coming out somewhere at the front after a long distance run.

i think i will continue to just keep topping it up until the leak becomes too severe, then send it in to get the seal replaced.

[timward]

sounds reasonable - provided you monitor the loss you wont run into any problems. I put it off for months and only got it done in the end because Oaktree said it was pointless even trying to start a 12k service as the whole front of the engine was plastered in oil

[dogsharks]

had the PO used a good synthetic oil it prob wouldn't have that problem now. I would check the underside of the pan, as the bolts get loose with time, but don't overtighten these. Of course, dry the engine off of all oil from underneath, with a bright light in hand and using absorbent cloth or paper towels. Then run the engine for a short time, go back underneath with a bright light, inspect and find exactly where the oil is coming from. If it's a neoprene seal, there are oils with more ester in the mix that are "supposed" to make the neoprene pliable and "swell it" but whether these really work remains to be seen. Nothing I've found so far in a can can fix a "mechanical" problem like a worn seal.

If it's a gasket, then there's hope.

Good luck.

Dogsharks



(I would NOT recommend going to a synthetic now, because if it leaks with mineral oil, it will just leak more with synthetic due to the superior cold flow)