2000 996 Oil Leak

Hi everyone, LONG time lurker here but never really posted. I joined back in the day when my dad picked up an early build 2000 996 as a "tester" to see how he liked living with a 911 before he bought a 991 C4S. I drove the car often and finally bought the 996 from him about 6 months ago (have coveted it for a long time) but have been running into issues. When he bought it, PPI noted the RMS was leaking but suggested replacement when clutch was done. The car only has about 48K miles but as I just left my career and started law school about 6 weeks ago I had a bunch of stuff addressed beforehand to try to ensure I wouldn't have major issues with the car while in class (that didn't work as planned...) Had the old (dual-row) IMS replaced with the LN retrofit, new RMS, clutch job, new water pump, new AOS, new motor mounts, and also new window regulators as they both broke within about a month of each other. The car was doing well besides for still having a VERY slightly rough idle, but has since refused to stop slowly leaking oil from the middle of the engine (same area it always leaked). I have had it back in to replace the RMS and get the leak fixed 4 times now and the car lasted about 5 weeks since the last fix and has just started slowly dripping again. My indy is concerned it could be an issue with the crankshaft. I was wondering if anyone on here has had similar issues and if it has been fixed at all. I'm taking it in for him to run further tests next week but am curious if anyone here has an idea for what could be going on. I obviously don't want to blow it all up and get a new engine or a new car, but am worried that if it is a crankshaft issue that I could be driving a ticking time bomb? I absolutely love this car and would be devastated if it died on me. any advice is appreciated. Thanks!

Law school + cheap Porsche = conflict. Law school + cheap car = get through law school and buy a real expensive Porsche when you�re done.

Haha, not too worried about the money. I had a good/successful career before I decided to go back to school and also have a large scholarship. I just don't want to end up in a bottomless pit time-wise where I don't have access to my car for weeks on end. I am able to borrow a car from my parents (who live nearby) usually but it's still a PITA. Also not really interested in a cheap beater to get through school. Cars are important to me. Also don't want a new fancy expensive Porsche. One day I'll get a nice 997 probably but that's as new as I will go. I don't like the electric steering in the 991 and they're too easy to drive/borderline docile when you aren't absolutely ripping through the RPMs. I got this 996 because I like that it doesn't have a glovebox, cup holders, traction control, etc. it's just a pure driving experience through and through.

Well, you sold me, lol

Is the same person that fixed it 4 times still working on the car?

Yeah, they're a reputable Porsche shop that has never had this issue before and they're as frustrated as I am with it, but if they don't get it fixed this time or at least figure out what's wrong I'm moving to another shop. I really like the guys and want to give them a chance to make good on the labor I've already paid them for, but if they aren't capable of figuring this out when I bring it in next week I won't be going back.

If 5he RMS is still leaking after being replaced, they need to check the crankshaft with a go-no-go gauge! if it fails, you need another engine/crankshaft. If it passes, they need to use the correct RMS Install tool. If they don’t know this, they DON‘T know the Porsche M96. I suggest they contact www.theknowledgegruppe.com .

Did they have issues with porous cases on the early 996�s Could it be weeping through the case?

One of the times I took it in they replaced the case through-bolts with the seal and it seemed to work for like a week but then the leak started again. The last time they replaced the seal with a new one again and it seemed to stop the leak for about 4-5 weeks but it just returned in the last couple days. Just a slow, 1-2 drops per day drip of clean/clear oil on my garage floor.

Excessive crankcase pressure can make the rear main seal weep. What weight oil are you running? What is your oil pressure at idle and running? You mention a slight rough idle...ever cleaned the idle control valve or MAF sensor? Last tune up (new plugs and coils)? As said, the part of the crankshaft that the RMS seals against can be checked for runout (roundness) with a digital gauge, and that should be checked. Also, the seating of the seal is very important and there are stringent guidelines for installation, including never touching the seal with your bare hands. It should be evident after the transmission, clutch and flywheel are removed if it is indeed the RMS is leaking, so pictures at that stage is highly recommended. Another source of leakage and weeping is the bolts for the IMSB cover. New micro-encapsulated bolts should also be installed while you are in there.

All of the above plus changing the spark plug tubes and o-rings. The tubes are plastic and even though you don't have a lot of mileage on the car, they are 18 year old pieces of plastic that are exposed to many heat cycles. Cracked tubes can account for rough idle and oil leakage.

Interesting, I hadn't thought of the spark plug tubes and I'll suggest checking that to my indy. A new MAF was installed a couple years ago but not sure if the idle control valve has been cleaned. I think it got new spark plugs (not sure about coils) a few years ago right after my dad originally bought it but I'll have to dig into the records. Running 5w-30 oil and oil pressure after engine gets really hot (high ambient temps and stop and go traffic) sits just around 1 bar, a little higher if it's colder outside and I haven't been sitting in stop and go too much..

Quotes source post: 15325021

The shop actually may be right. Did they test for rear main seal bore for alignment? Some say RMS leaks can't be fixed with repeated seal replacements until the crankshaft problem (i.e. crankshaft sag) is remedied. It will continue to leak unfortunately.

I don't think your car has an idle control valve. I think only the '99s did, though I'm not 100% sure.

5w-30 oil is too thin for the 996, particularly in LA climate. Should be running 5w-40

Sorry I just double checked and it actually is 5W-40

My 99 just developed an oil leak as well. Similar to yours. This might be dumb, but what side is the leak on? Mine is on the left if you are standing behind the car. I just had the oil changed recently and before that there was never a leak. Wondering if something else is developing.

If your spark plug tubes are 18 years old they almost certainly are leaking. Fortunately they are cheap to replace and swapping them out is fairly simple.