I don't know why it would be a clogged radiator since I took it out and ran water through it and back flushed it and there was good flow through it, but the passenger side hose and cooling pipe stays cool. I did the proper burping procedure but i will check again and leave the t-stat out to make sure. It seems that the WP works if it is moving coolant around and my heater blows warm which I was told tells you the WP is ok.

quote Originally posted by FIER086: I don't know why it would be a clogged radiator since I took it out and ran water through it and back flushed it and there was good flow through it,,,,,,

Sorry, let me try this again please.

The cooling fins. The air must pass through the cooling fins on the radiator. If the cooling fins are clogged up with debris, the radiator will never cool the fluid inside.

From time to time, we pressure wash the radiators on our service trucks as they gather alot of debris on the cooling fins of the radiator from being on the road.

Don't forget, what you're looking at when looking under the front of the car is actually the condensor, not the radiator, and grass/debris can get between the two and reduce airflow.

JazzMan

I checked the fins, and they are fairly clean, as clean as my other Fiero which does not overheat. Also I took my condenser off b/c I hate A/C. I will burp it again (i lift the rear end up a bit as well) and maybe I need to flush the rad. and passenger side pipes AGAIN. I don't really want to do it again because it is messy and time consuming and the first time I did it everything flowed really well. $%#$%#$^

Both Jazz and I posted to raise the rear a little, burp the system and run without the thermostat, that'll help narrow down what is up with the overheating.

Thanks jetman and jazzman for watching this thread and helping me, I will keep you posted on my progress later this week.

The problem was only getting worse until I remove the air bulb. I removed it by opening the thermostat plug at the engine, squeezing the rubber pipe that leads to the rad with my hands and screwing the thermostat plug back on. Worked I will do this again tomorrow, in case there is still more left, but I still want to change the water pump since it may be old.

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1986 GT Fiero Owner & Enthusiast
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wow, after looking at some old bills, the water pump was replaced 40 000 km's ago! wha hoo, don't need to replace it anymore

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1986 GT Fiero Owner & Enthusiast
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LISTEN FIERO86, your waterpump is shot. I had the same EXACT issue and the mechanic said it is the waterpump. Get a new one and save yourself from burning your engine/tranny.

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1986 GT Fiero Owner & Enthusiast
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I had this problem on mine and it was a pinched coolant tube.

Water was still FLOWING through the tube, but not fast enough. I couldn't even tell it was pinched until I removed the tube from the car. The bottom of the tube was round and looked fine, the top was pinched against the frame. I removed the tubes after battling this issue for weeks, changing water pumps, thermostats, caps, and what do you know? The problem was the pinched tube.

Just an idea. You may want to drop them and check.

I have this problem. Discovered the belt was too lose, allowing both the water pump and alternator pulleys to slip

. Bought tensioner from R. Dickman. Should solve both my alternator and overheating problems.

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Let me tell you about about my recent expeareance.

My wife drives about 50 miles a day, round trip to work, the past few weeks she came home, the radiator fan was running. No problem its 90 deg. +/- , wasn't worried, but the wife thought it was running a little hot. Wednesday I was following her home and she shot off to the side of the road 5 miles from home. She said she smelt the sweet smell of trouble and started off the road as the temp light came on. I went home and got some water, got back and filled the system and took out the thermostat. It was only 30 minutes or so and the thermostat was fully shut. OK maybe it cooled faster than I thought it would, but I left it out anyway. Got the car home fine.

Thursday I checked everything out. With the thermostat out I ran the car for 20 minutes. I had to shut the rear deck to get the temp to go past 220. At about 235 the radiator fan came on and dropped the temp down past 220 in less than a minute! So I went ahead and put in a new thermostat. Wife drove to work and back with no problem. When she got home the radiator fan was not running. She said the temp was just barly at 220 and that was from sitting in the driveway.

I must note at this time that the cooling tube at the rear wheel on the drivers side is crushed somewhat. PO backing over a parking lot stop?? This has never caused problems before.

I also tested the thermostat after all this. I've never tested one before. Got the temp up to 250 and it never opened. Then I did something for fun, I used a propane torch! I heated it till it was glowing before it opened with a loud pop, evidently you can open a stuck thermostat with enough heat. I then cooled it and it never shut completely until I shut it by hand. I'd have to say it was sticking.

If I hadn't noticed the radiator fan running for the past few weeks I would have tought I had something really bad going on, but, the system had no leaks, and no waterpump noise. So I was perty sure it was the Thermostat. My unorthodox test proved it.

Nick

[This message has been edited by the reverend (edited 07-18-2008).]

It is either my radiator or my water pump. But the radiator lets water flow thru it when I unhooked the hoses and stuck a garden hose in it and water comes out the passenger side. I assume this means it is o.k. Soon the clutch is being replaced, so while the engine is down I will replace the water pump and belts. I will let you know if any thing changes.

I had the exact same problem and it is now solved ! My guage was redlining within a few minutes and at the shop they told me it was either a blown head gasket, cracked head, or cracked block. I took it to a neighbor who is a mechanic and not in it for the money (he does it part time) for a second opinion. He bled the system, which by all appearances was full, and purged out so much air that he had to add a gallon and a half of antifreeze to top it off ! I also had him add a manual guage because of the unreliability of the factory guage. So basically what the garage quoted me 17.5 hours to fix (if even fixable), my neighbor did in 5 hours and about 60 bucks. I'm not sure what procedure he used to bleed the system, but everything works now as it is supposed to. I will ask him how he did it tomorrow when I pick up the car.