I have myself a 1988 iron duke Fiero. As long as I have had it it overheats if I sit in one spot for a few minutes in drive.Otherwise it runs great. The fan works fine and kicks on as well. I have already put a new water pump on it, and I have burped it many times. I checked the cooling lines and they seemed nice and clean and smooth on the inside. So at this point I think it may be a partially plugged radiator. I want to buy a new drop in replacement, but all I can find are these crazy 3 row oversized ones. The Fiero store says "This part is not currently available. Our supplier is not able to provide an ETA at this time". I just want it to be an easy drop in fit. I am nervous about buying an old used radiator, but at this point I am running out of options. Anyone got some advice? Or maybe want to sell a known good working spare?
Anyone else have this issue? Could it be something else other then the radiator? I think the exhaust manifold gasket is fine, so I doubt it is that. Or did the 3 speed auto Fieros just overheat if they sit still to long in drive? I just don't want to be stuck in traffic and start overheating this summer. (It has happened before.) And yes, it still will overheat even without the thermostat,
Have you carefully checked the metal coolant pipes that run down each side of the car. They often get crushed when a Fiero is lifted improperly. Crushed coolant pipes don't flow well... and can lead to overheating.
So at this point I think it may be a partially plugged radiator. I want to buy a new drop in replacement..... The Fiero store says "This part is not currently available. Our supplier is not able to provide an ETA at this time".
Can you get one at a local parts store? I'd rather buy one over the counter than have one get damaged in shipping.
I bought mine at Advance, which curiously no longer lists one in stock. Autozone has one though, part number A828.
Rock Auto has three different part numbers listed, but all are out of stock. Most likely the one Fiero Store sells is one of those three and if they're all out of stock both places there probably won't be any more until they run a new batch.
230°F is hot but not overheating. Coolant w/ 50/50 mix won't "boil over" until ~ 265°F w/ 15psi cap. But w/ 87+ l4 engine ECM should command Rad Fan On at 221°F.
If coolant pipes under car is bent even a little you have Crushed Pipe. Remove/loosen support hardware to look at rear of pipes at minimum. Many Fiero have broken rocker panels and body damage too because morons jack the car wrong.
Temp Gauge on dash often lies, Even when doesn't most T-stant can make big temp swings more so at idle or low speeds. Replace T-stant w/ Stant superstant. Even tho may look same as others, is not and stops wide temp swings.
See my Cave, Thermostat and most of rest of section.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
I went ahead and bought a 45818 Stant thermostat. When I had the gas tank out I remember carefully looking at the coolant lines, they seemed fin to me. Maybe that is not enough after all and I need to take a close look. I know the coolant tank says check when hot? Is it possible I am overfilling it? What is the a average resting level of the coolant before the car is warmed up? I always make sure the coolant is at least at the low marker before I go anywhere. I know I have past 230 before when I was stuck still for a long time, due to the fact that I started spitting out coolant on the ground. So I know my temp gauge is not that far off anyway.
Check coolant Overflow tank when Hot because heat makes coolant expand and push out coolant, and air if still there, to tank. If cold only fill to ~ add mark or ~ 1/3 between marks. Not Full.
I went ahead and bought a 45818 Stant thermostat. When I had the gas tank out I remember carefully looking at the coolant lines, they seemed fin to me. Maybe that is not enough after all and I need to take a close look. I know the coolant tank says check when hot? Is it possible I am overfilling it? What is the a average resting level of the coolant before the car is warmed up? I always make sure the coolant is at least at the low marker before I go anywhere. I know I have past 230 before when I was stuck still for a long time, due to the fact that I started spitting out coolant on the ground. So I know my temp gauge is not that far off anyway.
Have you stopped by a radiator shop? A good shop can re-core a radiator in some cases or flush a radiator. Or you could do what I did and get an aftermarket aluminum radiator. Again, a good radiator shop could hook upu up.
Champion has a three core radiator that is basically a direct fit. I have this radiator on three Meras and have had no heat related issues since I replaced the original radiators.
Every Duke I owned got hot until I burped the system of ALL air bubbles. Takes some doing, there is a procedure somewhere....been a long time since I've done it, but an air bubble free system is key.
I just purchased a radiator for my 84. (one week ago)The same one fits a 88 . Try Summit Racing # OSC 828 $195 with free shipping. This radiator is 2" thick and will cool 450 hp. It is all alum., no plastic tanks! Ps, it also fits a Corvette!
I first filled the radiator at the front. Then I filled at the engine. I started it for a minute and shut it off. Then I filled it again at the engine and restarted it. Did this 3 or 4 times and it was then full. Drove it for a while and let it completely cool, then checked again. Make sure your overflow tank has fluid in it before you start the process.
[This message has been edited by Roger Walling (edited 04-09-2021).]
Firezappy, I did this after doing the 3800sc swap but I used plain water rather than antifreeze just in case I had some leaks. No mess to clean up plus hot water on the floor surface will evaporate real fast.
I unplugged the fan connector for safety reasons and started with a completely cooled engine. As the thermostat begins to open the coolant tube inside the driver side rear wheel well will begin to get warm 1st. I wrapped my hand around it as it warmed up.
From there I went to the other end of that coolant tube at the radiator inlet and felt for a warm hose. Next point I checked was the hose at the radiator outlet and then back to the coolant pipe at the passenger rear wheel well. Once everything got warm or hot I went back to check that the radiator fins were equally warm over the entire surface. If there were any cool areas on the radiator that would indicate a partial blockage. I then plugged the fan connector back in.
Results may vary.....
Spoon
------------------ "Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut
Also take a look at the water pump. If you got a crappy plastic impeller, they can start dissintigrating making the water circulation less than ideal and causing overheating issues.
Also take a look at the water pump. If you got a crappy plastic impeller, they can start disintigrating making the water circulation less than ideal and causing overheating issues.
If you have to water pump off to check for that, you may as well install a new one either way.
Sometimes you can get an air bubble at the thermostat. This can prevent it from opening correctly.
Drill a 1/8" hole near the edge of the thermostat to allow any air to escape (make sure you install it so the hole is on the high side). This was an old thread on here that talked about doing this.
Any rad shop should be able to steam clean it or recore if it is a problem.
[This message has been edited by Mickey_Moose (edited 04-11-2021).]
Thanks for all the replies, I think I fixed it. My radiator fan strait up quit working, so I replaced it. I never knew how much air it was suppose to move, but this new radiator fan pushes much more air. So I re burped it again, and added a Stant thermostat. I need to drive it more to be 100% sure, but even the a/c has gotten colder when I am sitting still. So I have a good feeling. I just don't like leaving post without the 'solved' solution. Thanks again all!
