This looks like oil and water whipped together. What is it doing in my oil filler neck on an air-cooled engine? Do I have a condensation issue somewhere? Has anyone encountered this before? It is a 3.6 993 engine with 914-6 oil tank.

I have the same thing on my 993 engine if i let it sit for a while. It's condensation from moisture in the oil.

Do you have a vent to a catch can on your filler neck? I noticed that the bottom of the can fills up with a water/oil mix after a while which seems to evaporate back into the filler neck and cause even more sludge.

I try to get the engine fully warm at least once a week, keep the catch can empty, change the oil on a regular basis and clean off any sludge with a disposable shop towel.

Short drives and the motor not getting complete hot. I've read it takes about 30 minutes to be hot enough to burn off the water in the oil. 4cyl. Don't know about a 6.

You have a head gasket leak, allowing coolant into the oil system. Double-check the radiator cap!

--DD

Thanks.

My -6s will get a bit of that 'goo', though never that much. Probably after some humid weather and a short run that didn't burn off all the moisture in the oil tank.

Than again, you always have to be looking for coolant leaks in a flat -6!

It seems to be a warm up issue. I too run my car once per week for about 30 minutes, all year long, snow or not.
I just pull it out and let it idle till it's nice and warm.

Rich

I think part of the problem is that the 3.6L does not have an oil cooler on the engine.
I'm running 15 quarts of oil in my cooling system and i need a good 20+ minutes of driving before the thermostat even opens.

The oil temp hardly ever gets above 180 ...

I found the oil gets hotter, sooner, when I let it idle versus driving it.
Beside we have salt on the roads in the winter....

I do it specifically to burn off the moisture.
I also change my oil each spring regardless just to get all the moisture out.

This is a 3.2

Someday I wanna replace your thermostat and see if this changes. It could be stuck open, or partially open.