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Yellow stuff on the dipstick - 2007 Chevrolet Malibu

I have some yellow stuff on my oil dipstick. What is it and what do I need to do? The car does not overheat, so it makes me wonder.

That is a typical sign of water in the oil. Have your mechanic check for a head gasket leak. If you catch this early you can prevent damage to the engine. Water in the oil does bad things to the engine


+1 to SteveCBT’s comment.
However, I want to add that this is also a phenomenon that can take place when oil is not changed often enough–especially if somebody does a lot of short-trip local driving.
What can the OP tell us about his driving patterns and about how often the oil is changed, in terms of both odometer mileage and elapsed time?


I agree this could be a sign of frequent short trips. One of my friends was about to have his engine torn down when he noticed “mayonnaise” in his oil during a change. The mechanic wasn’t 100% sure there was a head or gasket problem and asked him about his driving habits. He drove maybe two miles to work and shut the car off. The same was true for the drive home and all his stops such as Wal-Mart and the grocery store were along that same stretch of road so he didn’t have to go out of the way for his routine shopping.

After the oil change he started making a point to take the car on slightly longer trips a couple times per week and wasn’t seeing any contamination. He took it out of town over the weekend once he trusted the engine. There were no signs of contamination after that several hundred mile trip.

This is why they suggest changing the oil more often if you never get the engine up to temp.

Do you do a lot of short trips? If so I wouldn’t be too worried.


But in that case, the OP should get into the habit of changing his oil more often–as well as taking one drive per week of at least 40 minutes, in order to “cook” accumulated water out of the oil.


Actually, I drive about 500 miles a week… almost all highway.

But, I probably could step up the oil changes to be every 3000 miles… a lot of oil changes in a short period of time.

Would that help?

You did not say how many miles between oil changes but 3000 might not hurt once . With highway driving 5000 or 6 months should be sufficient. I think having it checked for a head gasket leak like Steve said is a good idea.

You have all been a great help. I hope it is an easy fix, but the car has 212000 miles on it, so I can’t complain if it’s a bit more serious.

Thanks much

Does the oil appear clean? Has there been any coolant loss?

Some engines develop condensation high in the dipstick tube, if you see the contaminated oil high on the dipstick it is probably not a concern. Check the under side of the oil cap for the same condition.

The oil cap is clean. The bottom of the dipstick (where the oil level marks are) has the gunk on it

The oil is clean (other than the yellow stuff). Haven’t checked coolant levels for awhile.

The oil is clean (ther than the yellow stuff). Haven’t checked coolant levels for awhile.