Hey all. I have a cooling system issue, and it's not making much sense to me. So here goes...

The car is an 88 GT. The guy that I bought it from had just replaced the water pump, and we joked about the complicated burp procedure.
Joke was on me...30 miles down the road the car began overheating. While hot, it sucked the overflow tank dry. When released the pressure it refilled and overflowed the tank all over the parking lot. Ended up paying 3 bills to have it towed home.

"OK, this is easy" you say. "Improper burp left big air bubbles inside." That's what i thought, and others more car savvy than I seconded that notion.

So, bought some coolant and a new thermostat for good measure. Here comes the weekend...

Popped the thermostat cap and removed thermostat. Popped the radiator cap. Overflow bottle was empty again.
Filled coolant at thermostat housing. Immediately began to overflow at radiator cap, so it wasn't that low to begin with.
Reinstalled radiator cap and topped of fluid to top of thermostat housing.

When I started the engine to circulate the fluid, it immediately began spilling out of the thermostat housing. (thermostat and cap still out) It wasn't like air bubbles splashing the fluid out, it was a pretty steady pour.
After about a minute of this I got nervous and cut the engine. Coolant in housing immediately dropped low enough so that I could no longer see it.

I'm knowledgeable with liquid cooling on motorcycles, but this one confused me completely. I can't imagine this being a normal part of a Fiero coolant burp.

Any thoughts on what might be going on here? I have no desire to pay a flatbed to tow it back into town.

Thanks in advance.

Welcome to the Forum! How good a mechanic was your previous owner?

Thanks...good to meet you all...

It was a little indie body shop. The guys seemed very knowledgeable in general, but i know the Fiero coolant system is kind of quirky, so if he didn't burp quite right
I don't hold it against him.

You may have blockage in the heater loop...I suppose the heater has never been on in Phoenix...

...but it's a dry heat....(er)

from Orgre's cave "The correct caps for Fiero are Stant part numbers 10230 or 10330 non-vented caps.".

The front radiator cap may be incorrect.

Also check Orgre's cave for the coolant system burp procedure.

You will get coolant surging out of the open thermostat housing with the engine running. Any car with the thermostat housing / water neck removed / opened to atmosphere will expel the coolant through that big hole......

Fiero is the easiest car in the world to purge the air from the cooling system.

Engine off
Remove thermostat cap and thermostat
Remove radiator cap
Fill coolant at thermostat housing untill it starts to run out of the radiator at the front.
Install radiator cap
Continue filling at thermostat housing untill it is full
Install thermostat housing cap without the thermostat installed
Start engine and run for ~ 10 seconds and shut off
Open thermostat cap, top up and repeat the 10 second run time without thermostat and thermostat cap on.
Once the thermostat housing stays full THEN reinstall thermostat and cap. Should only take 2 sometimes 3 goes at it.

quote Originally posted by jelly2m8: You will get coolant surging out of the open thermostat housing with the engine running. Any car with the thermostat housing / water neck removed / opened to atmosphere will expel the coolant through that big hole...... Fiero is the easiest car in the world to purge the air from the cooling system. Engine off Remove thermostat cap and thermostat Remove radiator cap Fill coolant at thermostat housing untill it starts to run out of the radiator at the front. Install radiator cap Continue filling at thermostat housing untill it is full Install thermostat housing cap without the thermostat installed Start engine and run for ~ 10 seconds and shut off Open thermostat cap, top up and repeat the 10 second run time without thermostat and thermostat cap on. Once the thermostat housing stays full THEN reinstall thermostat and cap. Should only take 2 sometimes 3 goes at it.

Ahah...that might be the difference. None of the procedures I came across specified housing cap back on. They just said run with thermostat out and add coolant to keep topped until air purged.


Going outside to give this a shot.