coolant problem sti import v4

[Subaru Sti v4]

well my mech fitted the new thermostat and I got a new header tank!.
but I went for a drive a few days later after I checked the coolant level,
and it was still pushing the new coolant out of the expansion tank the one
near the battery!.
the coolant goes down in the header tank to the expansion tank but does Not
go back to the engine or header tank! what is going on??.. .

should I put a old thermostat in with the stat part open so coolant flows
around the engine ect.. . and block the expansion tank over flow pipe on the
top off??.. .

is it a good idea to to do this??? .. .

help please......... .

 

[Rick Courtright]

the coolant goes down in the header tank to the expansion tank but does Not
go back to the engine or header tank! what is going on??.. .

Hi,

Any chance there's some foreign material in the overflow tank that is
acting like a one way valve, stopping the reverse flow into the radiator
when things cool?

I've seen leaves, bits of paper or plastic and all kinds of other crud
(including a dead mouse!) in overflow tanks over the years. You might
want to remove the tank, rinse and drain it, and remove the little hose
and make sure it's not blocked, too.

HTH,

Rick

 

[Viktor]

well my mech fitted the new thermostat and I got a new header tank!.
but I went for a drive a few days later after I checked the coolant level,
and it was still pushing the new coolant out of the expansion tank the one
near the battery!.
the coolant goes down in the header tank to the expansion tank but does Not
go back to the engine or header tank! what is going on??.. .

should I put a old thermostat in with the stat part open so coolant flows
around the engine ect.. . and block the expansion tank over flow pipe on the
top off??.. .

is it a good idea to to do this??? .. .

help please......... .

Hey,
I had a similar problem with my Forester, and new hose clamp fixed the
problem. What happens is that when the coolant expands it flows into
overflow bottle, and when it cools down it suppose to go back into the
radiator. But if you have a tiny air leak somewhere, air will get sucked
back in since it's much lighter then coolant, and coolant will remain in the
overflow tank. There are several things to check: radiator cap (doesn't
seal properly), hose clamps, and could be something related your thermostat
replacement where something wasn't sealed properly (that's what I would
check first if you didn't have the problem prior)....
Good luck!
Regards,
Viktor.