Quick question: my engine is overheating, and I'm sure it's either a blown/cracked head gasket or a bad thermostat. I say this because the coolant looks bad; not sure if the coolant has oil deposits or gases, but it is brownish.

In any event, when I started the car with the expansion tank opened, I suddenly seen water shoot in the expansion tank from the skinny hose that is attached to the expansion tank. is this normal?

another thing: when the heater is on, the engine doesn't overheat, and the upper radiator hose doesn't feel terribly hot when the engine is overheating. Thanks for any info!

 

What kind of car do you have?

I have a 2006 530xi. The coolant has never been flushed. I just changed my water pump, because my car was overheating. I had the iDrive yellow overheating warning and the water pump had thrown a couple of codes. My old coolant was brownish looking.

Blown head gasket or other water intrusion problems yields coolant that looks like chocolate milkshake goo. So, unless you see the gooey stuff, you may just have old coolant rather than a more serious problem.

 

Thanks for the reply. I have an '07 530i. After looking at the coolant again, it is green, no signs of oil. Doesn't smell like oil or gas. I think it's the thermostat. Everything else is fine. heater,AC,,water pump, fan working...I havent changed the coolant in 18 months so I think that may be the culprit, or my cooalant temp sensor is bad again, and my hoses need changing. As long it's not a head gasket, I would be good....

 

Water shooting coming in from that small hole is totally normal BTW. The thermostat should throw some type of code if its stuck open or closed, had mine stuck open twice.

 

Hi all,
In regard to the coolant squirting into the expansion tank.
Is it always a solid stream?
I notice that sometimes it is spraying hard into the expansion tank and at other times it's like a trickle.

Thanks,
Bud