oil leak at rear of engine; any pointers?..

[smallspeed]

my car had a bit of an oil leak for a while which ended up being the hoses at the oil tank.. once they were all replaced, the oil leak seemed to disappear, the car using a bit of oil but not enough to raise concern.. since its been in winter storage ive noticed there is some oil leaking from the rear of the engine just infront of the exhaust primary-silencer, as there is a small puddle of oil (after 5-6 weeks) directly under the rear end of the engine near the middle.. Because of the plastic sheeting under the car at the moment, its not easy to pinpoint the exact area its coming from, as the oil has spread out within the wrinkles of the plastic I have cleaned it up and will check in a couple of days to see if I can see a few spots which give me a more accurate idea of where its coming from; the total oil patch probably amounted to 100ml..

I have had a good look underneath and cant see any obvious places its coming from; last time the car was in my indie they removed the undertray and cleaned the underneath of the engine as it was mucky, and there's no obvious oil marks on the casing, barrels, etc.

Are there any common leak's around this area or components which can fail causing oil loss? I have had a search on the internet and anytime you type oil and porsche in the same box on a search engine, you just get thousands of results relating to RMS failure on 986's/996's which haven't been much help!..

I understand these engines leak oil, however I'm thinking a leak like this while stationary would equal a bigger leak if the car was being driven..

Ben

PS.. its a high (180k) mileage engine, but runs really smoothly with good compression and power, and doesn't use much oil; maybe 1/2 litre per 1000miles, and I didnt notice any increase from that before it went into storage

 

[idc1873]

What model is it???

 

[38F3E1]

I think from your description you mean the end of the engine nearest the back of the car. If so the chain covers are known to leak sometimes.

Ian.

 

[smallspeed]

Its a 964C2 ('91 model year)

Im a bit confused by the "rear end" definition for rear engine cars; I looked at some RMS stories and it seems the rear is refered to as the end with the flywheel/clutch/gearbox on it?.. ..eitherway, Im refering to the opposite end from the flywheel/clutch/gearbox

any more ideas for me to look at would be good; hopefully I will get some time at the weekend to get under the car and have a proper root around

ben

 

[38F3E1]

The rear of the engine usually means the end where the gearbox is (ie pointing to the front of the car). The front of the engine usually means the end nearest the rear bumper of the car. Confusing I know.

As I said could be chain covers which cover the chains going from the end of the crank to the cams. Also check where any oil pipes attach to the crankcase. Also rocker covers on the sides of the engine, where the crankcase joins in the middle and where the crankcase through bolts are. Finally check the bottom of the barrels.

If you wipe it clean and look again after a few days you should ge an idea of where it is coming from. Don't start or drive it as this will blow oil everywhere.

Ian.

 

[nicklittle]

Had a similar problem recently.
After replacing the pipes to the oil tank the problem persisted. The cause was a metal pipe from the crankcase had literally rotted through. To change this the heat exchangers had to be removed to get at the fixings so not sure how easy it is to identify without their removal.

 

[smallspeed]

Thanks for the tips guys, i think there are a few idea's here, so I will clean the underneath up and see if I can spot anything developing.. Its not leaking loads, but its off the road at the moment so no problems with leaving it for a few days or a week and see what happens..

I will try putting some carpet (which will absorb the oil) under the engine as that should show more accurately where the drops are coming from.. My mate just had a new beige deep pile carpet fitted so I will use a few offcuts from that!