Coolant rushes out of overflow when rad cap openned???

[CanuckQx4]

Hey guys, I recenty came across a problem with my car I think. I openned the rad cap with the car flow yesterday just to check the level and look of the fluid, and fluid RUSHED up my overflow tank out sprouted out of the overflow cap threads. I closed the rad cap and the flow stopped.

Tried again today, same thing with the car cold, and again fluid rushed up the overflow.

WHat would cause this?? I dont wanna cause a big mess on my driveway but Id love to know why its doing this as I know Im now a bit low on coolant.

Thanks

[Dittoz7]

Did you let the car cool down? If not, thank Infiniti for not having a facefull of burning coolant.

[Dattebayo]

You checked your coolant on a hill.

[CanuckQx4]

Yes the car was completely cold obviously

And I did both cap removals in my driveway, which has a 10% grade at most, would that make a difference??

[Dattebayo]

Only in Canada.

[Dattebayo]

Your car ran just fine before you opened the cap, right?

Are you saying that the coolant rushed out of the overflow tank top or rushed out of the radiator cap hole?

[CanuckQx4]

Ya car ran fine just wanted to check all fluids.

I'll go try it again since I havent driven it today and see what it does.

[Dattebayo]

NO, i'd leave it be.

It's probably just siphon action going on.

[PapaSmurf2k3]

"RUSHED" out of the overflow tank?!
I am intrigued... wanna make a video of it?

[Jesda]

Its probably due for a coolant flush anyway. Pay a shop $100 or less and leave it alone until its due again in a couple years.