Q: Milky residue at the oil cap

asked by on

I've found some milky residue at the oil cap. Is it normal or is it the head gasket blown?

That depends on a lot of things. If you don’t drive much, especially if you are one of those people like my wife who drives 3 miles to work and 3 miles back, you can get an oily residue.

This is because as gasoline burns into the atmosphere, one of the by-products is water vapor. You’ll always get a little bit of water vapor in the engine that’s mixed with oil and gets a creamy color because you don’t drive it hard enough. When you are going 65 on a highway, the engine is running and everything is hot but the water is just going to evaporate and go away. You don’t have to worry about it making a mess.

But, if you are still concerned, watch my video "how to tell if your head gasket is blown" and then you’ll see if the head gasket is blown or if it’s starting to blow. Know that it is a big deal replacing a blown head gasket. So you’ll want to pray that it is just normal residue from not driving the car long enough, or not changing the oil frequently enough.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Milky residue at the oil cap

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car quit and won't restart

The intake gasket on these engines are known to fail and you will get a large amount of unmetered air. A smoke test will reveal if the gaskets are leaking. If the intake gasket is leaking, the repair is extensive....

Q: driving and car cut off brakes lock and it want start even though it will turn over like it is going to start

The brakes need the engine to run to supply vacuum to the brake booster. This is why brakes are hard. The engine cut off can be from several reasons including a broken timing belt, bad fuel pump and loss of...

Q: The motor is sucking a lot of air from the plastic valve cover

The pcv valve may be stuck open or fell part inside causing excessive suction in the engine and high idles. Have the crankcase ventilation system checked for problems.

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.