Coolant residue around overflow tank...
 

Merry New Year!

I've been noticing coolant residue around the cap of the overflow tank and continues to grow. The cap is tight. I was told that the overflow tank wasn't pressurized so I'm curious how this is happening. Anyone else experience this?

Thanks!

Lew

overflow tank may have a hair line crack and the dried coolant will dry up near where it is has seeped out as the radiator warms or cools.

Post a good pic with a flash. That may expose any visible cracks.

I took a few pics this morning and will post them later. The residue is around the fill cap. However, I noticed that the dealer overfilled the coolant when I had a flush done at 60k. Car has been sitting for two days and the coolant level is past the MAX line in the tank. That could be the problem. I will have them drain some out when I go in for service next week.

i would not assume that is overfill. when the car is at operating temp the cooling sys would suck some of coolant back into the radiator.

Well,

I just called the dealer for an appointment and explained to the service writer what the issue was. He has seen this before and could be an air pocket somehere. He did confirm that the coolant was flushed at 60k, and they have ALWAYS overfilled the coolant (even when I took delivery 3.5 years ago). It won't be going in until next week, so stay tuned!

Lew

Car is at the dealer. The interesting thing is that the temp needle has never moved past the default setting and no signs of leaks.

Welp,

The dealer couldn't figure it out. No leaks, T-Stat seems OK, and hoses are in good shape. They flushed the system again (free) and didn't overfill it this time. I'll peek under the hood in about a week to see if there is any new residue.