I agree... no way to have that much pressure in the coolant system without a blown coolant seal, but normally it wouldn't hold pressure then. Again... use an emission's sniffer on the radiator filler neck.



Good luck.

You said you replaced the coolant cap, did you pressure test the cap? It's one in a million but ever once in awhile I get a brand new part that doesn't work. That's about the only thing I can think of :/

I pressure tested my cap and it's good. I hooked up my pressure tester to the system and started the car. The first 30 to 45 seconds the engine already built 7 lbs psi. I'm afraid to say it, it looks like a rebuild is in my near future. This just sucks!!! https://www.nopistons.com/forums/pub...1047683358.gif

Unless I'm mistaken it should build some pressure on startup because the thermostat is closed. When the thermostat opens pressure will drop lower and the coolant will flow freely. If the thermostat doesn't open it can overpresurize and over heat causing it to boil over into the overflow.



I'm grabbing at straws here, I know it's not cheap to do a rebuild, best of luck

Re: Losing coolant through the overflow tank
 

Hey guys, Sorry to bring this back from the dead but how was the issue resolved?

I have the same problem; Fresh rebuild- Add Coolant Buzzer comes on at startup in the morning after driving it prior night.

Leaks coolant from expansion tank area but then stops.

Top off the system and everything is ok and then problem restarts.

Can't be the coolant seals as the car was not overheated during or after rebuild but will try to diagnose to rule out coolant seals.

Re: Losing coolant through the overflow tank
 

Go drive your car and get it really hot
then park it and check your overflow tank
do you hear gurgles and bubbles? or is it pushing out coolant

Re: Losing coolant through the overflow tank
 

K went for a nice drive and listened by the expansion tank.

Heard some normal sounding heat ticks but no bubbling without popping the hood and I put my ear to the crease (cause im at work) No coolant on the ground either.

How loud would these gurgles and bubbles be Potato?