White foam on oil dipstick
 

I noticed a bit of white bubbly foam on the oil dipstick last night. So I started reading about possible causes and a blown head gasket came up. I decided to check for other symptoms and this is what I found.

1. Slight amount of white foam on the dipstick, no change to the condition/appearance of the oil itself and no odd smell.

2. Checked the oil cap, no sign of anything.

3. Checked coolant level, no loss of coolant.

4. Checked for bubbles in the coolant when I throttle it up. Bubbles foamed up after about 30 seconds of running it.

5. Checked exhaust for white smoke or odd smell. Nothing.


Car runs great, smooth, does not overheat. I'm a bit lost here.

Does the car get used for a lot of short trips? If so, take her out for an hour long run on the highway and report back.

Condensation often forms on dipsticks, on the inside of oil filler caps, etc. It mixes with the oil to give a white or light brown color. A good long drive will allow the condensation to burn off and the oil will return to normal.

If the symptom persists, have a repair shop use their exhaust gas analyzer to 'sniff' the coolant for hydro-carbons

Or....buy a DIY "Block Test Kit" which used a dye to detect hydrocarbons in the coolant

Cheers
DD

Short trips are about all I drive, I work at home so 90% of it's driving is running the kid up to school (5 miles) and back. That being said, I was still concerned about the bubbles forming in the coolant tank when I increased the throttle. Is that not a sign of something gone wrong?

Thought I would add, the bubbles in the tank after hitting the throttle are very tiny, almost like the head of a beer.

The bubles MIGHT be caused by what you are afraid of, or by the increased water flow. Do as Doug suggests. If the white stuff is worse, you know you have a problem, if it is better, give the ol' girl a good run now and again.
Watch for loss of coolant, overhaeating or misfire.

Thanks much, I'll go driving. I just have a feeling it's not a big deal, the car runs great, plenty of power. Heat gauge stays just a bit left of center and doesn't move. Our weather here has been odd, 55-60 during the day and 20-30 at night with plenty of moisture in the air, don't know if that as anything to do with it...

Normal. It's what we call an 'idiot gauge'. It's designed to give a *fixed reading* over a very wide range of temperatures and only move to the right if the temp exceeds xxx-degrees


It might !

Cheers
DD

You have had some weird weather and cold spells. Will be noticeable more during cold weather. I never start and run my cars for short periods. I always drive and warm up everything I own until the gauge or heater blows hot, usually 3-4 miles at hwy speed.

Drove it and drove it pretty hard for about 35-45 miles. Came back, had a bit of foam, wiped it clean and stuck it in again, came out clean. I decided to test the coolant tank, zero signs of hydrocarbons, fluid stayed blue. I checked the oil again after running it for the coolant test and it had more white foam. It's only showing up on the dipstick, I see no sign of it on the oil cap.

Well, it will get worse or not, but there is nothing you should do at this point. Don't worry, be happy!

Got it running hot again, this time there was no sign of foam or anything except oil.

I'll keep an eye on it but I believe you guys were probably correct in the condensation diagnosis. Thanks to all of you for the good info.

I used to think that 3-4 miles or even 10 was sufficient. SWMBOs Beemer has an oil temp gauge instead of coolant. In cool weather it can take 20+ miles of driving to get the oil up to full temp.

I had some white foam a couple of weeks ago. Ran a wooden dowel down and back a few times to remove the residue. It's a winter, short trip effect.