Oil pressure/ oil-water mixing

[FONT=arial"] Hi My first post since joining earlier this month. TBH, didn't think it would be one looking for technical advice, but there you go. Picked up my 02 996 C4S from Autobahn in Coventry early in March. The car had 57k miles on the clock, I've done just over 1000 miles in it, mostly A roads and motorway with one short urban run. Got a message to check the oil level from the computer this morning. I think this may have been a phantom, as the car was parked on a slope and wasn't properly warmed up - run for perhaps 10 mins from house to petrol station. I put in about 700ml and the level returned to nearly full on the dashboard guage. My first problem is that on opening the oil filler cap (which I had not done since buying the car), there were traces of a mayonnaise like substance in the neck of the filler pipe. With many years of Lotus Elise ownership under my belt, this really does worry me - its a tell tale sign of gasket failure in a K series. Should I be worried about this in a 996? (I'm thinking yes, unfortunately). Also, the oil pressure. Its usually run at between 3 and 4 bar, but today, even when warmed up was showing 4-5, dropping just below 4 when I come off the throttle on the approach to lights, say. The only other thing I can add is that there seems to be nothing else untoward going on that would indicate a major problem. Car starts fine, doesn't smoke at the tail pipes, idles and accelarates without complaint and the oil consumption, I think has been fine. It sat between just under half and about a third full every time (low oil warning above) excepted. Fuel consumption has been averaging 25.7 and a tank range of about 260 miles all the time, which is pretty much what I would have expected from the car. I'm going to call Autobahn in the morning to see what they think of this, but if anyone can throw any light on it just now, that would be most welcome. Cheers John

A little mayo in the oil cooler tube is normal, just as as long as it is a little and not as if someone has exploded a shaving foam can in there. Have you checked the water level? No oil in there? Your oil pressure readings are unclear. I normally have about 4.5 while cruising at 3000 rpm but have as low as 1.7-1.8 at idle. I also have a 55k ish car (allbeit a 98) and intend sorting this slightly low oil pressure by using a 5/40 or 10/40 oil next change. I doubt you have a problem but your garage visit will give you peace of mind.

[FONT=arial"] Paul Many thanks for the quick reply. It is a little - certainly not like a can of shaving foam. Will check the header tank again, it seems clear. Its next run is to the garage to have some work done on the stereo and I'll get them to check out the oil then. Cheers John

As Paul says, traces of mayo are fine & normal. When the car's been sitting on the flat for 20 plus minutes, the oil level display on the dash should have all the bars lit - form your description it sounds like yours is low (?). The car is *very* sensitive about being absolutely flat & level otherwise the reading cannot be trusted.

Yes the mayo is normal. I took my 1999 996C2 to the Porsche garage about it and they said its perfectly normal. In summer its gone. My oil pressure is as follows. When cold its at 5. When warmover 3500rpm its between 3 and 4 and flat out its near 5. At tickover its as low as 1 after a hard thrash, when the oil is very thin. Again I asked and that is fine. You have nothing to worry about. Enjoy.