Air-cooled car... water in oil? Does not compute.

[RobFrost]

I gave the 911T a good warm-through today and parked it up level to check the oil while running. It was an inch or two below maximum. But there is clearly at least a little water in the oil - condensation on the underside of the oil cap and a creamy white oil/water mix in throat of the filler.

Presumably some of last night's extremely heavy downpour has made it into the engine. With the open grille directly above the engine suspicion falls on the breather tubes on the top of the engine. Is there a common place or places where water gets in, in particularly adverse weather conditions?

[911hillclimber]

In the case of my '73, the engine is well protected from rain fall if the filters are in place. The carbs would need to be exposed for a long time and the accumulated water given time to drain into the combustion chamber(s) and past the rings, and to the oil; bit unlikely?

With that contamination, you need a simple oil change and filter, engine running hot before hand (so the crud is all mixed into the oil), the right oil for old engine design, and run it well.

I would suggest the oil level hot should be between Max and Min with the car on level ground and allowed to tick over to get the oil into the dry sump tank and settle before looking at the level.
Do not overfill!

[Sam]

Condensation is normal and often nothing to worry about, especially if you’ve been doing shortish (<20 minutes or so) journeys. Wipe away the gunk and monitor it.

[hot66]

As sam says, common if a car has been started and either not driven far or very short journeys…oil doesn’t get hot enough to evaporate condensation in the oil. Seem to remember er it was even more common on old air cooled vw motors

[RobFrost]

The carbs would need to be exposed for a long time and the accumulated water given time to drain into the combustion chamber(s) and past the rings, and to the oil; bit unlikely?

Carbs sounds plausible.. the four screw holes on the top of each carb cover must have had a little water seep through into the pistons... and then on into the oil. The rain was torrential.

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[70sThrowback]

I think its more likely condensation. If its just a little residue / white creamy substance. Wipe it away and go for a good drive.

[jwhillracer]

Perfectly normal for an air-cooled engine if it hasn't been driven hard. Water in the air as the crankcase breathes condenses in the cooler parts, such as the oil filler neck. As said above, if it annoys you, wipe it out, and then take it for a good run!

JW

[inaglasshouse]

Yep, good run, get it nice and hot. Job done.

[RobFrost]

I took your advice and got the oil warmed through - I'm sure that's driven any moisture out. My first drive out to Curborough Sprint Course and - not on the track - just on the way there. I joined a while back and haven't received any membership details yet so I thought I'd drop in to say hi and see what the score was. There was a 6R4 waiting to go out this p.m.

[911hillclimber]

Italian Service technique comes to mind!

[christaylorsound]

Graham is right, I'd give it an "Italian tune up" ie. a proper good blast, get the oil hot for an hour or more and only then check the condition of the oil filler, most likely clean!

[camperco]

What they said..