Frozen slush in oil/external leak

Our 2017 equinox had a puddle of oil underneath it and the dipstick looks dry. Sort of. There is crap on the dipstick as well as on the oil cap that looks like little chunks of frost/frozen sludge. Almost was like if you pulled a straw out of a slushy. The car has about 70k miles, we use full synthetic, and it’s been below zero the last couple of days (though the car is in the garage/not outside). Bottom of the oil cap for sure is iced up.

Is this frozen slush indicative of anything, especially when couple with an external leak? Blown head gasket. We haven’t used synthetic oil until recently and I didn’t know if it acted strangely in cold weather.

Synthetic oil looks like oil at low temps. Conventional oil might look like congealed fat.

So you have a leak. Add oil. Fix the leak.

The goop on the inside of the cap is liquid mixed with oil. Either condensation from lots of short trips and too infrequent oil changes… or a blown head gasket pushing coolant into the oil.


Ask your shop to double check the coolant freezing point is low enough for your climate. Sometimes plain water gets added to top off the coolant level in the summer, then forgotten about, dilutes the anti-freeze protection. Top off oil level first of course.

Check the PCV system for blockage.

ie: Ice in the PCV hose.



Yep. Probably PCV. I pulled the PCV hose and water/yellow goo gushed out for an amazingly long time. Subsequent to Tester’s post I was reading up on it, and this vehicle is famous for condensation in the pcv system freezing up, which builds up pressure, which blows out the rear seal. The yellow slime I was describing is a symptom of this, as is all that water gushing out the way it did.

The car needed three quarts of oil to top it off, so hopefully I didn’t damage the engine other than that seal.

When I turned on the engine with the oil cap off it was as through the oil fill was the exhaust pipe, there was such a strong pressure blowing out of the oil fill. I’m guessing that’s saying that the pcv system is still blocked. My understanding from watching a few youtube videos is that in these gm products the pcv orifice under the manifold is very small and gets clogged and must be cleaned out. If I were to clean the pcv orifice is there a potential that relieving the pressure would stop the rear seal from leaking? I was assuming that once the seal started leaking that was it, the thing was junk, but I wasn’t sure.