Oil Leak, but could it be RMS? I'm really not sure....

Evening all. New member and new to this site so a big hello to all ! Had a fantastic day at Brands Hatch today. Did my first track day in my 1998 996 C2. Thoroughly enjoyed it, drove well, had good instruction and even managed to get past another 911 and a Lotus Elise. Very please wil myself. Not so pleased with myself however when I drove back to my garage and noticed a knocking noise coming from the left hand side of the engine. The noise was worse if I bent down beside the nearside rear wheel. It's sounded either mettalic or possibly the sort of noise you get on an exhause manifold leak. Oil pressure fine, oil level fine all things checked out lovely. Until ! ! OIL ! ! I noticed a small puddle gathering on the floor. It drips down to the left hand side of the engine, just behind the nearside rear wheel and then again about 6 inches closer to the centre of the car, still on the left though not at the centre. There always was some dampness on and around an indented nut or plug of some sort and if fear it has now developed into a leak. My car is a Tip and although it's entirely possible, the RMS is a less common problem with Tips. I have driven the car hard many times. I use it every day to drive to work in the City (64 mile round trip) but it just so happened that something went at the track today. I switched off the engine, allowed it to cool somewhat and then decided to head home and do some research. Haven't found anything yet that really sounds like my symptoms. On a brighter note however, the engine knocking noise had stopped when I restarted the car and was still quiet after a nice relaxing law abiding drive home. Hydraulic lifter oil starvation? RMS? According to Parr (where it was last serviced) they did alert the previous owner of an oil breather pipe on the left of the engine that needed replacing. But was that left looking backward or left looking forward? I will find out tomorrow. In the meantime can anyone help or advise from past experience or knowledge of their own? I'm expecting a large bill of some kind but with the engine knocking like that and the oil leak I would like to know what it could be before someone tries to baffle me with "it could be's" and bills me for the privilledge. If I had damaged something I would expect the engine to continually knock, I could have blown an exhaust box, they do look tired. Are there any issues with oil starvation? I have had to put 1/8 litre of oil in in today to take the level up to where it was before I hit the track but have seen no oil pressure warnings or even poor readings at the gauge. It reads about 2 bar on idle when hot and 4 1/2 bar when cruising with an engine speed of about 1500rpm so looks healthy enough from it's readings. The right hand side of the engine seems fine. Any help would be appreciated. If there are any R25 Porsche Club members on here then a good recommended indy in Kent will be appreciated too, especially one that offers discount with club membership ! ! Many thanks for your time. LeeRoy.

Welcome Lee! Left side is left side looking at the back of the car. It doesn't sound like RMS to me - that would be in the dead centre of the engine, not to the left side. Are you sure it was oil? The position you dscribe is exactly where the coolant tank drips when it leaks. As for the knocking noise, it could be a hydraulic lifter, but it might also be something as simple as a loose spark plug - I've heard of a couple of those recently. It sounds like a metal scraping sound, not what you would expect at all. However, if it's quiet now I wouldn't worry too much, and just keep an ear open for it.

Hi Richard, It was definitely oil. However very dark in colour and was only serviced by Parr in February. Maybe it could be oil getting washed down, there was water with it but that was probably from the wet track today. The coolant tank was replaced in 2006 so I do hope it hasn't gone already ! Car has only done 8000 miles since then. I suppose I would see a loss of water or engine temperature rises which I haven't seen yet. Do you know of an oil breather pipe somewhere on the engine? Thanks for you time !

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