p951guy

i cleaned off the yellow oil cap on my car last time i changed the oil in ie... 500 miles ago... and noticed a yellowish colored slime on the bottom of it. i checked the oil when i drained it and there seems to be NO anti freeze in it. There also appears to be No oil in the overflow tank so all the seals seem to be keeping the oil where it is supoosed to be and so are the seals keeping the antifreeze where it is supposed to be. Any ideas what it could be... should i worry about this?
Thanks

Rog

Hi,

you were right to think of moisture, but it doesn't have to be from your cooling system.

Any other place water could be getting in?
Around base of filler neck? Dipstick tube?

How's the rest of the oil?

regards
roger

Tom

You should definitely monitor your oil and coolant but my thought would be condensation in a warm engine. Water is a by-product of combustion, and the weather you have been having has probably been cold and damp. have you been making trips long enough to warm the car up thoroughly and evaporate the water out? This is somewhat normal and why oil changes are time as well as distance related. See if the sludge is there after a nice long fast trip.

Renntag

You are right to be concerned...but alas, this is normal. ALL of the 944s I have owned and dealt with have experienced a little residual condensation shmeg under the oil fill.

Clean it with brake clean and continue to monitor the vitals(fluids at such)... You will see it is nothing to be alarmed about.

Isnt it good to get good news too?

newoldguy

I would agree with the diagnosis that the engine just doesn't get hot enough. All the more reason to make sure you do frequent (3 month) oil changes.

Hans

Condensation and petrol in the oil can come from driving short distances so the engine does not get hot enough.
That sludge will also be in the carter ventilation system so oil change and cleaning in reduced intervals will be a must.

My favourite way out:
Drive a longer distance say once per 2 weeks.
Make sure you are on the road for min 30 minutes. This will clean out the moisture and vaporise the petrol, thus will save you an oil change or 2.

One of the most appreciated features nice of Porsche's is that you got to exercise them..
Take care

Tom

This is also why, if your car is ih hibernation mode, to avoid the temptation to go warm it up a little every so often. If you can't really drive it, better to just let it sit.

IceShark

If you have significant ambient temperature changes you are also going to be more prone to getting moisture condensing in the engine. I don't know what is up with climate in North America this year but the temp swings are pretty large .... maybe global warming.

You should also keep in mind there may be an issue about water in fuel supplies with the wide temp swings. With the ethanol winter fuel this can be a real problem. If your car starts to run like crap, bad fuel should be at the top of your list. People have even devised schemes on when and how to buy gas to avoid getting a load of settled ethanol and water (they are heavier than gasoline and will settle to the bottom of the station tank where the pickup tube is.)