Milky, foamy dipstick but coolant res and top end look okay???

[SonicAdventure]

I've got a real confusing problem. My oil was recently changed and about 250 miles later my dipstick is covered in frothy foamy residue. There is no inordinate fluid in the coolant res. When I take the oil filler cap off there is nothing but clean oil up top. No egregious oil leaks; just a little seepage from rear crank seal.

The car usually only gets driven for 4-5 miles a day and it's pretty much stop and go city driving 80% of the time. Today I took a long highway trip probably 1 hr, pulled the stick and this is what I saw.

I watch Roberts video and others on head gaskets. But I still don't know what to make of this. This didn't start happening until it got cold here.

[EstVolvo]

What is the temperature gauge doing when driving on a highway? Is it going down?
How many miles are on the thermostat?

[SonicAdventure]

Temp gauge slowly goes to midpoint from cold start up and pretty much stays at midpoint even when going 50 thru 70 mph. On a hot summer day sitting in traffic it might creep slightly past midpoint. I have no idea how many miles are on the thermostat.

[EstVolvo]

I would:
A. check if it has negative or positive crankcase pressure
B. replace the thermostat

[JeffHicks]

I don't know where you're located, but if you're in a cold climate, just driving a couple miles per day will draw a lot of condensation into the oil pain. And the engine doesn't get hot enough, for long enough, to work the moisture out.

It is at least "possible" that you have no problem at all.

[SonicAdventure]

I'm in philadelphia. We've had some crazy weather the past few weeks; going from the teens to the 60's with a snow storm last week. The car is parked in a parking garage at night where the temp is a pretty consistent 40-50 degrees regardless of outside temp. So the possibility of condensation is quite possible.

To me the presence of obvious moisture in the oil pan but no other symptoms of head gasket failure (no froth in top end, nothing wrong with coolant or coolant levels, no copious white exhaust, etc) seems to indicate some kind of moisture issue in the oil pan.

As far as crankcase pressure, I have to do the PCV job, planning to do it within the next month or so. Smoke from dipstick, not too much, but also fills the rubber glove over the oil fill hole, so yes that is an issue.

As far as driving, it usually gets driven no more than 10 miles round trip per day, with an occasional 20-30 min drive once a week. The car rarely gets over 60 mph.


Will replace the thermostat tomorrow. What is the best brand to buy?

[EstVolvo]

I don't know about different brands. Probably stay away from the cheapest ones. They are pretty cheap, even from a dealership.
There may be a different opening temperature for the thermostat depending on whether you have a turbo or an N/A engine.

[abscate]

That is too much froth for new oil with a few hundred miles on it.

I think you will have to look for a head gasket leak, an oil cooler leak, or something else.

[polskamafia mjl]

The car usually only gets driven for 4-5 miles a day...

This is the source of your problem. Moisture in the motor needs to boil off otherwise it creates that milky residue. Take a bike instead of the car.

[rspi]

Get a Volvo, Wahler, or Vernet. I have even seen Colorstat (I think). There are a rash of thermostats sold at auto parts stores that DON'T EVEN FIT. Causing the car to run on the hot side.