Coolant pressurised when cold

Coolant pressurised when cold

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dr_gn

Original Poster:

16,380 posts

191 months

Saturday 17th August
quotequote all
Update in case anyone’s interested:

Because the car is a shed, I left it and drove 350 miles home from holiday without issue. Wife drove it to work for the past 2 months with no issue. Whenever I checked the cap it gurgled like mad when stone cold (apart from a couple of times when it was fine).

Anyway, long story short, we’ve now got an identical 2001 Civic with 70,000 miles on it as well as my wife’s at 130,000 miles. The new Civic doesn’t gurgle. Ever. I swapped the radiator cap, and the new Civic’s cap cured the issue. So bought a brand new Honda cap, and the problem is gone.

I’ve still not figured out how the cap allows the expanded coolant to re-enter the system on cooling. The expansion tank isn’t sealed to atmosphere I don’t think.

Anyway, it is what it is.