Coolant Geyser out overflow tank cap. Anyone else?
 

About a month and a half ago, I had coolant coming out of the overflow tank cap area like a geyser. I got worried. But, filled it back up with coolant 50/50 mix and watched it. Until today, it has been fine. But, after picking up dinner, it again. But. I am almost positive it is a weak cap seal. It is not coming from the radiator itself.

So I called and left a message for Ford parts for a new cap. I pick it up tomorrow morning. I'm hoping that's all it is!

I know the car is ten years old. Is this normal for the seal to fail? Anyone else have this problem?

mine only ever puked once- out in colorado, just went over a mountain pass, (was running in third, sounded nice) pulled int my Dads- first drive off the highway coming in town- shut it off got out, knocked on his door and poof, car sarts blowing water out...

never did it before or after, thinking it just heat soaked from shutting it off so quickly after a hard climb... in retrospect, shoulda let it idle a few minutes to cool down a bit...

Ohhh hmm. Yeah, it wasn't too hot today, but maybe it was enough to do that.

Thermostat going?

That crossed my mind, too. But, it's not overheating just the coolant is overflowing.

coolants only overflowing because its boiling in the motor- if it wasnt pretty major steam expansion, it would just flow into the expansion reservoir...pretty much only way its boiling is low pressure(like you mentioned the cap might be weak?) or its actually getting that hot in there- slow water pump/clogged radiator tubes/clogged radiator fins, or a lean issue- bad o2 sensor/bad injector/too much alcohol in the gas- or a bad head gasket blowing combustion gasses into the coolant...

or, what was hopefully the culprit in my case- just a really hot motor getting shut off...if you have a temp gage, they normally get hotter immediately after shutting off, as the water quits flowing, but the iron/aluminum is still at the temperature that flowing coolant holds under control...

my old 396 ran a 180 thermostat, always shot to 215-220 after shutting off even in winter...and these cars run hotter thermostats.

My guess would be thermostat sticks. Trans cooler leak into rad could also cause overflow. Head gasket can also cause coolant overflow.

Hmm, interesting! Thank you Tim. I hope it isn't something serious. But, I think I'll call and have my shop look at it this week. My radiator has some small dents in it I noticed as I was moving the horns for the grille install I did.

ARGH! It puked again only after driving a little bit (though some was on the highway). My guess is you guys are right about the stuck thermostat. It spilled all over the driveway. I called the shop to give them a heads up on the message machine. But, I really hope they can take me in tomorrow. :explode::shakefist:

https://cimg4.ibsrv.net/gimg/themust...99f62da3f3.jpg

I hope the fix is a simple one. Nice car you have.

I have a really good friend who came to the rescue. He diagnosed what was wrong! The fool who last did the cooling flush, didn't bleed it. Tons of air bubbles. It wasn't boiling the coolant. We purged it and voila, she drives smoother than I have ever felt and no more overflow issues! My mind is at ease! :salute:

Sweet! Glad it was an easy fix.

Thank you so much! Me too!!

Well. The story doesn't end here. Earlier today, after some highway driving, it bubbled up again. My friend said it could still have some air bubbles in it that are trying to make their way out. The overflow was not as prolonged as last time. And, I went for another drive tonight and it is fine. He told me to keep driving tomorrow and call him tomorrow afternoon and we may do a thermostat replacement and a coolant flush. But, we shall see. This whole thing is like a nightmare that won't end.

:devil:

:banghead: Ok I succumb to the mechanics. I cannot handle the stress this has created. I made an appointment with my shop but they can't get to me until Tuesday. It bubbled a ton today! Something is totally wrong.'

Having to have to buy a "new" used car after the rear ending was hassle enough. But, this redfire car has been a HUGE disappointment.

Sorry it's still having a problem. Hopefully they fix it easily.

Thank you David! Me too!

:banghead: More drama!
It looks like Sarah could have a more serious issue. They tested the coolant overflow cap for pressure, it wasn't holding any (16 lbs is normal) and he said it has been running for an hour without any bubbling over. I get ready to go pick the car up and then they call back saying it overflowed and right at closing time. So now I have to wait until tomorrow to know more about what the issue is. :doh:

Finally, resolution to this frustrating month.
It was the thermostat that was sticking. I hope this thread gives someone else help in the future. I know I would appreciate seeing others' stories in times of confusion and frustration.

So a new thermostat has everything fixed? Good news.