Quick review, car got hot, spewed coolant everywhere, couldn't figure out why.

I've since discovered that the coolant is filling in the overflow and coming out of the cap. I installed a new thermostat (195*)and filled the system, same problem. Within 3 miles of driving it begins to get hot and start overflowing the resovoir. Could it be the radiator cap? I checked the fan and it is working. Surely not just a bad cap would cause this. I removed the hoses up front and they check out just fine.

Help please! I'm relegated to driving the in-laws '84 DeVille.

------------------
1987 Silver GT Automatic

A bad/weak radiator cap can do this.

I'm liking this answer!

yes, if the spring in the cap is soft, it will not hold the pressure in the cooling system, and let it all burble into the overflow tank. If the overflow tank is full, it will flow out the lid on that, and make a steamy stinky mess. Lucky you! easy fix!

Thanks guys. This place is like an interactive Haynes manual without the corny, unhelpful pictures taken from obscure angles.

Just don't forget, its also possible you have a blockage somewhere in the system. Hopefully its the cap though; easy fix.

Oh, and the stant catalog is WRONG. DO NOT buy a vented cap. You want a 16lb non-vented cap. Disregard the catalog, and just shop by looking at the caps, thats how I do it.

[This message has been edited by Rainman (edited 06-10-2003).]

The Stant radiator chart at AutoZone specifies a vented cap. Fieros need a Non-Vented cap. Otherwise when the car sits and cools off with the nose slightly down, coolant will siphon out through the cap through the overflow bottle onto the ground. This will then cause an air bubble in the cooling system with subsequent overheating.

Great, that info will save me some hassle. One more question: How do I properly refill the system? From another post I learned to fill the radiator first and then fill at the thermostat housing. Should I raise the rear up to burp out any air in the system or is there another way?

thanks again!

Edit: Stant part # is 11230 for 16lb non-vented. $5.03 with tax to be exact.

[This message has been edited by TennesseeGT (edited 06-10-2003).]

Here is what I do based on the Helm's manual. It works for me.

Start this procedure with a cold engine.
Coolant is 50/50 mix antifreeze/water.
Park with the nose slightly down.
Remove the T-stat housing cap and remove the T-stat.
Remove the radiator cap.
Start to fill from the T-stat housing until coolant starts to run out of the radiator filler neck.
Install radiator cap.
Continue to fill at the T-stat housing until full.
Install T-stat housing cap without T-stat.
Start engine and run for a minute to get circulation.
Remove T-stat housing cap and top off coolant.
Install T-stat.
Fill overflow bottle with 3 quarts coolant.
Start engine and bring it up to operating temperature.
Shut down engine and let it cool. It will draw in coolant from the overflow bottle as it cools.

[This message has been edited by Carrolles (edited 06-10-2003).]

Thanks. That's close to what I did last night after I "thought" the thermostat fixed the problem. I did pretty much exactly that except for not putting the T stat in and running for a minute. I will try that tonight after adding my spanking new radiator cap.