Opened Expansion Tank, It Burped, Normal?

[PeteB]

Car had been running for over an hour, parked it at home, off for 3 minutes or so
and I opened the cap on the expansion tank and it sort of burped, seemed to have
suction then splashed a bit of coolant out. Is this normal? Have not done this many
times so not sure?

We are losing about a cup of coolant per year and I don't notice any drips. Is there
a good way to check? Dye in the coolant?

Could it be the headgasket going?

[scot850]

Pete, I can't recall what work you have done on the car but I know it is a lot.

Worth checking this current thread:

https://www.matthewsvolvosite.com/forums ... =1&t=78257

Neil.

[PeteB]

Regarding the cooling system, I did replace the tank and the top hoses that
were easy to get to, did not do the lower or heater hoses. We drained the
coolant and switched to Zerex G05.

Thanks, I'll take a look at the other thread.

[abscate]

You opened it still under pressure. It takes more like 30 minutes to bleed off presssure.

A cup a year coolant use won't be easy to find nor diagnose...and you really shouldn't worry about it.

[Clemens]

As abscate says (remember, mods are always right): it is normal. I personally think the p80 cooling is somewhat strange as it easily fools people to think it is acting erratic, but a cup a year is no problem at all. I had an odyssey with water level and burping last fall and after a few months of checking daily i came to the conclusion that everything is fine.

[beigg]

Once had a heater core oring seeping just enough to not find the leak, yet lose coolant. Enough in a six month's time span that raised a brow and determine where/why.

The reservoir would pressurize and still burp once opened. How I found there was a problem worthy of finding is when I added just above the cold fill once the system has rested over night and then running the vehicle around town made that fluid push out from the cap.

I later added dye and pumped up the system with the test pump and went looking.