Gunk in the oil dipstick tube

Dave in Maine · Post by **Dave in Maine** » 21 Nov 2018, 11:00

Here's a new one - at least to me.

I stopped to check the oil in my 96 850 turbo sedan (~205k) this morning. When I pulled the dipstick I was horrified, because it looked like pancake batter. Knowing this was a sign of Serious Trouble, I called my mechanic to discuss and ask him to start working up the price for doing a head gasket. Before going there, though, the car was about 400 miles short of oil change time and I had some time, so I told him I'd get the oil changed and have the tech report on what, if anything, he might see that was out of the ordinary. I had changed over to synthetic this past summer.

The oil change tech reported nothing out of the ordinary other than the oil being "dark", consistent with 5600 miles out of a recommended interval of 6000. So I decided to drive around and called the mechanic to report what the tech had found and see when he'd be available for a couple minutes so he could look for himself.

An hour or so and 20 or so miles, mixed about 50-50 between surface streets and freeway, I was at the mechanic's.

We pulled the dipstick and saw the same pancake batter but also clear new oil at the correct level. On closer inspection, the thick goo was only on one side of the dipstick, AND it was all the way up the dipstick.

Looking down the dipstick tube we noted pancake batter-looking goo hanging onto the inside of the dipstick tube. It was getting scraped onto the dipstick as it went in and out.

Our conclusion was that "no, there probably isn't a coolant-oil mix going on" but other than that we're mystified.

Ideas on the cause? On how to clean it out of there?

Post by **Rattnalle** » 21 Nov 2018, 11:27

Sounds like a mix of oil and water vapor being pushed up the dipstick tube by excessive crankcase pressure. A little bit of water in the oil from condensation and such is normal but as long as it stays in the oil it usually boils away.

Sommerfeldt · Post by **Sommerfeldt** » 21 Nov 2018, 11:53

The "pancake batter" is EXTREMELY common. Like Rattnalle says, it's a mix of oil and condensation, forming as a result of the oil not getting hot enough to boil it off. This most often occurs when you take short trips only, not letting the engine heat up for long enough before shutting down. Take the car on a spirited drive for an hour or so, and like you saw, it clears up.

You can't clean it out, but should treat the symptoms just like you did. Do it at least once a week if all the car sees is short trips on most other days. Let it loose a bit as well, so you get it nice and hot.

(within legal limits, of course). Check your oil often, and a PCV overhaul might be a good idea if you haven't done that the last few years.

- S

Post by **June** » 21 Nov 2018, 11:57

If there is any water/ coolant in the oil it will also show up on the underside of the oil cap as a off white crud. Your mechanic could do a combustion gas test to the cooling system to properly rule out a head gasket leak. Because if it has a slight problem now it may avoid a all out failure potentially ruining the engine much less leaving you stuck with a tow bill on top of a replacement engine or car.

Post by **jimmy57** » 21 Nov 2018, 12:08

Did you let the engine run at idle for more than 15 minutes from cold start before the pancake batter was noticed?

Post by **misha** » 21 Nov 2018, 12:29

It's just condensation from frequent short trips in cold weather...don't worry about it.

Post by **abscate** » 21 Nov 2018, 12:58

Just add syrup and butter and you are ready to go.

Post by **misha** » 21 Nov 2018, 13:03

Teddy1975 · Post by **Teddy1975** » 21 Nov 2018, 13:31

Sommerfeldt wrote: ↑21 Nov 2018, 11:53 You can't clean it out, but should treat the symptoms just like you did.

Actually, you can. The dipstick tube is removable and can be flushed

Whether it's needed or not, that's a different matter.

I've cut a length of pipe foam insulation and wrapped it around the dipstick tube. It seems to be working rather well in preventing condensation inside the tube, even with my many less than 10 miles per trip.

Sommerfeldt · Post by **Sommerfeldt** » 22 Nov 2018, 06:19

Teddy1975 wrote: ↑21 Nov 2018, 13:31 Actually, you can. The dipstick tube is removable and can be flushed
Whether it's needed or not, that's a different matter.

I've cut a length of pipe foam insulation and wrapped it around the dipstick tube. It seems to be working rather well in preventing condensation inside the tube, even with my many less than 10 miles per trip.

Well... yes. You can clean the tube and prevent just that spot from having condensation (mostly), but that’s not the only or probably even main place it occurs. As someone said above, you’ll also find it on the inside of the oil cap, signifying that it comes from and originated from somewhere else.

It’s generally better to boil it off once or twice a week, so it doesn’t accumulate, at least.

- S