I am new to the forum. I actually bought my first Fiero a couple of weeks ago. Sorted out a few problem already(Thanks in part by you guys THANK YOU), now I finally got to drive it this morning. Off to work I go and 20 miles later as I pull in the parking lot my temp shoots up from 110ish to 240 and then shoots back and forth. I hop out and there is fluid coming out the top of my overflow container. I parked on an incline with the back of the car higher than the front. Let the engine cool for a couple hours. When I opened the cap on the thermostat the engine was empty of fluid. No leaks under car anywhere except where it came out the cap on the overflow container. Container by the way is now at normal level. So i filled the chamber in Thernostat housing, started car for 5 seconds and refilled. Repeated 3 times. Levels stayed where they were. So i decided to drive it home. 20 miles later as i make my first stop near my house it does the exact same thing. So I backed in my driveway, so back of car was higher than front. Same things as arrival at work. Fluid pouring out of overflow. This time I didnt wait but 10 min and opened the cap on the Thermostat and sure enough the block was empty of fluid. Air in system? I dont think head gaskets are blown. It runs good. No Coolant in the oil. What could be couasing this??????? HELP??????

Air in the system. Check the Ogre's cave link at the top of the page for the way to burp all the air from the system. The gauge is moving rapidly most likely because there is a steam pocket in the cylinder head that the sender is touching. It is also a good idea to replace the thermostat now as well to make sure it is functioning.

For some reason when I try to enter the Cave my internet explorer crashes. Whats the deal?

Put on a new radiator cap.
Good Luck
Gary

I use Firefox and don't have a problem with Ogre's cave. The idea about the radiator is a good one too, is the cap on correctly? It could be bad too causing the coolant to go to the overflow. Do you have a pressure tester? You can test the cap(s) and the system with a pressure tester.

I will have a new radiator cap when I get home, but why would that cause these symptoms? How do I burp the system as well? After reading a few posts on here I remembered that I also turned on my heater for a few seconds right before this happened. Not sure if thats relevant or not but just wanted to give all the information.

Hi,
I am in the process of diagnosing my cooling system as well and think i have it all figured out but havent gotten to test yet. Anyway, what motor do you have? 2.4 or 2.8? It would be a good idea to start with the simple, general stuff:

1) burp system to get rid of air
2) replace thermostat, theremostat cover (if gasket is cracked), radiator cap (if gasket is cracked or spring is corroded)
3) check that the steel pipes that carry coolant along the sides of the car are not crushed. (if they have any dents on the bottom, there is a good chance the tops are kinked as well...even the small dents can be a problem)
4) check the fan for operation (it should come one when the AC is turned on, and also at 235F)
5) check/clean radiator fins with degreaser and a hose (grime can cause it to cool less efficiently)

If none of this works you have to look into your specific situation. If you do have the 2.8 this could be a slipping plastic impeller in your waterpump. I just changed mine and will post some pictures of old versus new when i get a chance. I dont know if they were oem or aftermarket, but some waterpumps have a plastic impeller pressed into a steel hub. This hub gets pressed onto the shaft. The problem is that the steel expands almost 4 times faster than the plastic due to heat and eventually the plastic impeller cracks and slips on its hub.

Anyway, try the simple things first for the sake of money and time, then there is a lot more fun to come!

Good luck

what year and size engine do you have?

I do have the 2.8 and there are no dents or crushed pipe that i can see. Is there a way to check if the water pump is working without taking it out? One other thing. I pulled out my brand new thermostat because the car shot up to 240 in a couple minutes just idling in the driveway.

If/when you buy a new radiator cap be sure to get a NON-VENTED cap. All parts manuels are wrong and that may cure your problem.

You can check the waterpump without removing it by removing the pipe from the top of the wp, snake a metal hanger into it and jam the impeller. Then remove the belt and try to turn the pulley while the impeller remains jammed. I was not able to remove the pipe so i just planned on replacing the pump whether it was plastic impeller or not (it was plastic).
wp was $35 from national parts (with closed metal impeller)

good luck

I did not have the Thermostat in when I drove it and it stayed around 110 the whole 20 miles until I slowed down and turned. Then it Jumped to 240 and back down to 110 then back up to 240. As stated before, when I opened the Thermostat cap it was empty of fluid in the engine.

you should make sure the fan is coming on via the temp sending unit, if it is not, when you come off the highway to slower speeds/stops, the radiator is useless with no airflow. The block was empty because the coolant was expelled through the overflow tank. Have you checked your compression? or your oil for coolant?
Does the overflow tank overflow when the car is cool/warm? Or only when it's hot?

I have not checked for compression, but seems to be running good. There is no coolant in the oil. It has not overflowed except for the two times today.

i had this situation a couple of years ago and met the unfortunate demise of my crank ripping in 1/2 inside my engine. but i dont know still to this day why it happened.
--matt

Well I got home and tried to do do that test where you start the car and open the thermostat cap to watch the coolant flow. Started the car cold and went to open the thermostat cap and it started shooting out fluid as I was turning it. Blown head gasket?

not necessarily, it will gush out if the thermostat is installed, if the lines are clogged, or if there is air in the system. You also have to let the car run for a few seconds so the coolant starts to circulate, then open it. Some people have reported it gushing no matter what.. Do you have smoke/steam from the exhaust?

No smoke or steam. Installed new radiator cap. Put thermostat back in and took it for a ride. Temp reached 230 without opening thermostat. Shut off car. Thermostat opened and temp dropped to 180. That to me means after startup air is blocking thermostat from reaching opening temp.. Any thoughts. How do I find the burp procedure on the cave?

[This message has been edited by mykkal (edited 09-16-2010).]

well if your not burping it properly all bets are off. I think in the ogres cave you read terms and cond, then click on drivetrain on the left, then coolant fill, but not positive. How do you know the thermo is opening? If you drill a 1/16" hole in the flange of the t-stat, it will let trapped air out and prevent vapor lock.

I know the Thermostat wasnt opening because my coolant lines to the radiator were not getting warm while the engine reached 240. as soon as i shut off the car they got warm. Therefore, that is when the thermostat finally opened. A friend of mine suggested that it could be possible that the guy I bought it from may have put the belt on wrong and the water pump might be running backwards. Is this possible?

Not really.

Take the thermostat out, take the radiator cap off. Fill the engine with coolant till the coolant comes out of the radiator cap. Then replace the radiator cap. Continue filling till the coolant is up to the neck of the thermostat housing. Replace the thermostat housing cap. Start the car and see if you can get the thermostat cap off without it gushing fluid. If not have someone up front releave the pressure by turning the radiator cap back and releasing the pressure into the overflow tank. Do this till you can get the tstat cap off without gushing fluid all over. Then let the engine idle a bit refilling the tstat housing. You may need to cap the tstat housing and releave pressure at the radiator a bit more as the caught gasses expand. Don't let the cooling system pressurize. Finally you should be able to see the coolant flowing at the tstat housing and have the air out. Leave the tstat out but cap both front and back and take it for a drive. After the drive, and after letting the engine cool so there is no pressure in the system pull the tstat cap, fill to the top, insert the tstat and cap and you should be good.

Follow phonedawgz instructions for filling and get the air out first...Also, make sure you have the overflow filled to the mark on the side of the bottle, this will prevent the car from sucking in air as it cools.
When i filled mine, i had the t-stat installed (with a 1/16" hole in it) so that it forced the coolant to flow in one direction and force the air out the other way. You will see bubbles coming out of the 1/16" hole while you are filling. Once the bubbles stop you have filled most of the cooling system and block. pull the thermostat and top off the housing...then do the running burping procedure (without the t-stat)
That is what worked for me.

It would be a good idea to buy one of those infrared thermometers ($50 at harbor freight). it is a very usefull tool and you can see changes in temp everywhere...it makes it very evident when the T-stat opens, when the coolant is circulating, where hot spots are, how efficient the radiator is working...and much much more. You can use it to check for equal temps at your exhaust/intake manifolds...very usefull tool

btw, when the engine warms up, does the heater blow hot air?

Hope this helps!

Thank you guys! I will give it a shot, and post the results.

Well guys I tried all your suggestions. I burped the system. Had good solid temp with it idling. Nice hot heat from the heater. Took off down the road for a tes drive and got 2 blocks from home and the water pump/ alternator belt snapped. Turn around and got back home. It got pretty hot. Just above the red on the temp guage. Replaced the belt and attempted to reburp the system. I burped it for over an hour with a funnel burping system. The kind you attach directly to the radiator cap. I kept getting bubbles and it now overheats every time I take a hard left turn. Weird I know!!! I tried to burp it the way you discribed but I cant get the thermostat cap off without it blowing fluid everywhere. The funnel burping kit doesn't come with a big enough cap to attach it to the Thermostat housing. What do I do? I feel like the burping kit isn't working while connected to the radiator.

We are still assuming the radiator is not blocked and the water pump is the metal version and is working.... Has to be a hose or blockage somewhere I would think... A left turn crimp. Trans Cable ..Clutch?.(grasping I Know!)... have any of the hoses been replaced.... turn wheel to the left and see if anything up front or back is pinched. Pull all the hoses.... do the water pump impeller test , run a snake through the stainless lines......looking for a blockage or a tennis ball/coke bottle (LOL) and then the only thing left is the radiator.... at this point don't assume! .... was the broken belt torn or burned?

------------------
Mark
In the Great Northwest!

[This message has been edited by NW-Fiero (edited 09-20-2010).]

A few suggestions:
1) burp the system with straight water instead of a coolant mix, so when it gushes out of t he t-stat housing it doesnt make a huge mess. and remember, no t-stat installed for this.
2) the burping procedure...do not remove the thermostat housing until the car has run for a few seconds (maybe 15 seconds, but not when the engine is hot), this give it some time to equilize the pressure and get the fluid flowing
3) if you open the t-stat housing and the water gushes/sprays out, this is when you buddy cracks the radiator cap open. it is gushing because you have air in the system. i found that with mine i had it running with the radiator cap off more than on while i was filling the t-stat housing. if the level of water in the housing started to get low my buddy capped the radiator for a second while i caught up. eventually the water will run smoothly through the t-stat housing and only water will come out of the radiator cap (no air)

If water gushes sprays out of your t-stat housing while the radiator cap is off adn the t-stat is not installed, i think its safe to say you have some serious blockage in the system. I could be wrong, just my $.02

Good luck

I have not replaced the water pump, so I am not sure if it is the metal type or not. Should I just replace it? Could this be the problem?

I think I can say with certainty...... if it is not the metal version it will fail in time. and if it is and has failed ... it needs to be replaced. Have you done the water pump test

quote You can check the water pump without removing it by removing the pipe from the top of the wp, snake a metal hanger into it and jam the impeller. Then remove the belt and try to turn the pulley while the impeller remains jammed.

------------------
Mark
In the Great Northwest!

I have not tried the pump test. I will give it a shot.

quote Originally posted by phonedawgz: 2.8? This is how the 2.8 belt runs, execpt without the extra idler pully. The belt just makes a big triangle.

Just wanted to add here that this extra idler pully is available from Rodney Dickman and is totally awesome...

Totally worth whatever it was that I paid... (don't remember).

------------------
Todd,
2008 Jeep Patriot Limited 4x2
2002 Ford Explorer Sport 2dr 4x2
2002 Ford Crown Victoria LX
1987 Pontiac Fiero SE / V6
1973 Volkswagen Type-2 Transporter

I had the same problem with my '85 2.8, It turned out to be the water pump. Even though it had a metal impeller, when it got warm the impeller slipped on the shaft and coolant did not flow. I replaced the pump and drove the car another 50K miles until the frame rotted out so badly i had to cannibalize it.

I am going to replace the water pump. I will post the results. I appreciate all your help.