Hi! New here, long time Mazda enthusiast. My first (and still have it) was a 1986 RX-7.

I recently bought a 2005 Tribute, V6. The rad was leaking a bit, so I put Bars Leaks in it (the engine was running at the proper temp-no overheating, just leakage).

That didn't help so I got a new rad. New rad is installed and now coolant is coming out of the overflow. I have changed a few rads and never had this problem. Should I get a new thermostat?

Any ideas would be appreciated, thanks!

 

Coming out when running? What happens when engine off? Running temp normal?

Last time I had variations in level it was as air was purged from the system, this engine sometime seems to need a while to get all the air out. Until that is done air expansion in the system can cause the level to rise and overflow, then the air bubble will move to the coolant tank and the level will drop again...YMMV but I'd ensure she is purged first.

Can't see any reason to change the thermostat. Generally I don't use any stop-leak product as I have seen pipes blocked with the resulting gunge rather than it sealing a leak as intended.

 

Rule of thumb is always change the thermostat when swapping a radiator or water pump. Is it possible the system was overfilled and is finding equilibrium with the run off?

 

Do you have heat from the vents when commanded?

You could always check upper hose temp vs lower hose temp to verify thermostat is opening.

 

sounds like it what nickndfl mentioned ,
check coolant for overfill

 

Thank you all for your replies! I did check and try those things, and did swap out the thermostat.
And...it was two hoses at the bottom switched by mistake...!

I am admitting it as it might help someone else LMAO (insert embarrassed smiley face here)