Scum in oil tank

[jonboy996]

Went to check my oil level yesterday, noticed a light brown scum gathered around the top of the filler cap. The same stuff is around the coolant filler as well. I drive a '99 996 C2. Should I be worried?? Is this the first signs of the RMS on its way out??

[truckpdt]

I've seen this once before myself and researched it at the time. Basically it's condensation in the filler cap combining with the oil and it forms a light brown substance. It's certainly not desirable as it's ruining the quality of your oil...although probably wouldn't be fatal. This situation is the result of short journeys were the car doesn't get a chance to warm up properly.

Now I could be wrong about the above. I have a 993 and a BMW 530i...it's the 530 I saw this on and I was at the time doing a 3 mile journey in the morning to the train station. Of course I could be totally wrong about this condition in your 996.

[verysideways]

jonboy996 said:

Went to check my oil level yesterday, noticed a light brown scum gathered around the top of the filler cap. The same stuff is around the coolant filler as well. I drive a '99 996 C2. Should I be worried?? Is this the first signs of the RMS on its way out??

Don't see how water in the oil system would be anything to do with RMS, ever. Water in the oil system, or vice versa (both ending up with lots of that grey 'mayonnaise'), is usually a sign of a failing (or failed) head gasket.

If it's just a little bit, and especially with the wet and slightly cooler weather we've been having, i'd been inclined to agree that it's simply the moisture in the air. Have you done short journeys recently?

[GreenV8S]

Water in the oil may not be a problem, oil in the water definitely is.

[Vesuvius 996]

jonboy996 said:

Went to check my oil level yesterday, noticed a light brown scum gathered around the top of the filler cap. The same stuff is around the coolant filler as well. I drive a '99 996 C2. Should I be worried?? Is this the first signs of the RMS on its way out??

Totally normal. Short journeys, cold weather, long filler neck causes condensation of hot oil containing small amount of water vapour.

Don't sweat it.

And it is nothing to do with RMS.

Edited by Vesuvius 996 on Monday 23 October 10:37

[Vesuvius 996]

GreenV8S said:

Water in the oil may not be a problem, oil in the water definitely is.

Sorry missed the bit about the coolant tank. This is not good news. Get it checked out.

[jonboy996]

Thanks for all the help, cars in for a service next week so I'll bring it up

Thanks lads

[zcacogp]

Scum gets everywhere - sorry to hear it. There's lots of scum in my neighbourhood as well, any ideas on how to get them out?

<Hat, coat, heading for the door .... >


Oli.