quote Originally posted by 82-T/A [At Work]: Haha... yes, for sure. I'm just curious if anyone has seen anything similar... such as a similar issue.

haha ha....yeah I have. it's the ground under the dash usually. it's stealing the ground for the temp gauge or it's having a poor connection and drawing a little too much power which is also a thing (the gt does alot of things like this).
I would reground the decklid and body and see what happens

quote Originally posted by 82-T/A [At Work]: Also... can you guys confirm that the coolant comes in FROM the drivers side (thermostat side). I would hope so, since that coolant appears to be much cooler... while the passenger side (exit at the water pump) appears to be hotter. I don't even know what to think if you guys tell me it's the other way around...

You have it backwards. The coolant supply to the engine is on the passenger side and goes to the inlet of the water pump.
The thermostat housing on the drivers side of the engine is the coolant exit from the engine, down the driver side, and to the radiator up front.

Everything looks fine...

If the engine was really overheating, the coolant hose on the driver side of the radiator would be 220+ degrees. My guess your is in the 180-190 degree range.

quote Originally posted by cartercarbaficionado: you are describing the formula to a T. the waterpump is not flowing coolant properly and is recirculating inside the block due to excess clearance. some pumps are litterally 5 mm too short and it causes nightmares but only with the Stat installed.

Interesting... I'm not really having any overheating issues from what I've been able to determine... but I bought a new waterpump and waterpump housing, because I do have a slight leak... which I think is the fault of using the wrong thread sealer on the block for the thermostat housing. So just in case that IS an issue, that'll be rectified anyway.

quote Originally posted by cartercarbaficionado: haha ha....yeah I have. it's the ground under the dash usually. it's stealing the ground for the temp gauge or it's having a poor connection and drawing a little too much power which is also a thing (the gt does alot of things like this). I would reground the decklid and body and see what happens

Oh man, I don't think I even saw a ground for the dash... I'm definitely going to have to look at that. The decklid and block are both ground pretty well. I have a ground strap to the engine block on both decklid hinges... so that's good. But I definitely never saw a ground for the dash. I'm going to have to see where ground is on the dash, and maybe add an extra lead to the frame. Thanks!!!

quote Originally posted by fieroguru: You have it backwards. The coolant supply to the engine is on the passenger side and goes to the inlet of the water pump. The thermostat housing on the drivers side of the engine is the coolant exit from the engine, down the driver side, and to the radiator up front. Everything looks fine... If the engine was really overheating, the coolant hose on the driver side of the radiator would be 220+ degrees. My guess your is in the 180-190 degree range.

Thanks, I don't remember where I was referring to it... but I've got that straight now. I've verified that it is in fact going that way. With the new radiator I have... it comes in hot on the passenger side (of the radiator), and the passsenger side of the radiator (where it exits) is like super cool...

Just going to bump this so I can add a few things to it. As I probably mentioned above... I determined that in fact the car is NOT overheating... but that the gauge is not reading properly.

Two points that I've considered:

1 - It could be something with the wiring harness (not the gauge cluster).

2 - It could be the sensor. I posted about this on Reddit a couple of months ago. Someone had a similar problem and said they had a sensor that was doing the exact same thing. When they replaced it, it fixed the problem. So I just swapped it out.


We've redone the front of the car (which we're still finishing up), just got everything back together and installed a 4 or 5-core radiator. I can't remember which... it was totally overkill for the Iron Duke, but at the time I was trying to do anything i could to mitigate what I thought was an overheating issue. The radiator barely fits under the factory brackets. We had to basically modify them using pliers, an anvil and a mallet to re-shape it.




We also installed a new condenser in front...




She sanded and repainted everything up front... this is after she re-installed the front bumper...




Anyway, it'll be a couple of weeks (we're going on a trip), but once we fill it back up with coolant, I'll report back if the sensor fixed the problem (for the sake of thread closure). I am not sure if I mentioned it above, but I took the opportunity to completely remove the waterpump, replaced the gasket, and checked everything... no blockages or anything like that.

quote Originally posted by 82-T/A [At Work]: Just going to bump this so I can add a few things to it. As I probably mentioned above... I determined that in fact the car is NOT overheating... but that the gauge is not reading properly. Two points that I've considered: 1 - It could be something with the wiring harness (not the gauge cluster). 2 - It could be the sensor. I posted about this on Reddit a couple of months ago. Someone had a similar problem and said they had a sensor that was doing the exact same thing. When they replaced it, it fixed the problem. So I just swapped it out. We've redone the front of the car (which we're still finishing up), just got everything back together and installed a 4 or 5-core radiator. I can't remember which... it was totally overkill for the Iron Duke, but at the time I was trying to do anything i could to mitigate what I thought was an overheating issue. The radiator barely fits under the factory brackets. We had to basically modify them using pliers, an anvil and a mallet to re-shape it. We also installed a new condenser in front... She sanded and repainted everything up front... this is after she re-installed the front bumper... Anyway, it'll be a couple of weeks (we're going on a trip), but once we fill it back up with coolant, I'll report back if the sensor fixed the problem (for the sake of thread closure). I am not sure if I mentioned it above, but I took the opportunity to completely remove the waterpump, replaced the gasket, and checked everything... no blockages or anything like that.

some of us only have overheating on our early dukes because the 2 speed we spent a month finding caught on fire (car is fine more a mild annoyance than anything)
also you just gotta flex that pretty paint that wasnt done at 3 am after a case lol. in all seriousness i havent had the time or money to fix this ones body enough to then spend 1k painting it black or blue after finding all the correct cooling system parts that were 84 specific it might get done this year or at least get primer

[This message has been edited by cartercarbaficionado (edited 03-30-2025).]

quote Originally posted by cartercarbaficionado: some of us only have overheating on our early dukes because the 2 speed we spent a month finding caught on fire (car is fine more a mild annoyance than anything) also you just gotta flex that pretty paint that wasnt done at 3 am after a case lol. in all seriousness i havent had the time or money to fix this ones body enough to then spend 1k painting it black or blue after finding all the correct cooling system parts that were 84 specific it might get done this year or at least get primer

Yeah, it can be a pain in the butt. This car has been a fairly solid car, but the level of detail that we've committed to is absurdly financially unfeasible. We're definitely not going to do this with the Corvette. I'm going to "make" gaskets rather than source ultra-rare gaskets from wherever, and re-use bolts from my bucket of bolts, rather than buy specialty bagged bolts remade to OEM specifications, etc.

For us, the exterior of the car already had a decent paint job. It's a re-spray, which is probably not the greatest, but we've been able to sand and buff it out at the edges. Having removed all the panels too makes it easier for us to properly clean-up overspray and things that the re-spray had. We bought it like this... the paint is good quality, but they didn't remove anything, just taped stuff off when they repainted it. There were many parts we had to remove, remove overspray, and then touch-up with a rattle can (sprayed into a cap) with a small brush. If I had to give it a score... 10 being what the car was like brand new, and 0 being the fiberglass is literaly rotting, I'd have to say it's a solid 7. There's no areas where the paint is fading at all. And it looks quite good a few feet away. It just doesn't have the "luster" that factory paint would have. But totally not worth repainting the entire car at this point since the paint is still good.

But yeah, I get it... restoring a car never makes financial sense. It has to be an action done purely out of sheer love of car, or insanity.

quote Originally posted by 82-T/A [At Work]: Yeah, it can be a pain in the butt. This car has been a fairly solid car, but the level of detail that we've committed to is absurdly financially unfeasible. We're definitely not going to do this with the Corvette. I'm going to "make" gaskets rather than source ultra-rare gaskets from wherever, and re-use bolts from my bucket of bolts, rather than buy specialty bagged bolts remade to OEM specifications, etc. For us, the exterior of the car already had a decent paint job. It's a re-spray, which is probably not the greatest, but we've been able to sand and buff it out at the edges. Having removed all the panels too makes it easier for us to properly clean-up overspray and things that the re-spray had. We bought it like this... the paint is good quality, but they didn't remove anything, just taped stuff off when they repainted it. There were many parts we had to remove, remove overspray, and then touch-up with a rattle can (sprayed into a cap) with a small brush. If I had to give it a score... 10 being what the car was like brand new, and 0 being the fiberglass is literaly rotting, I'd have to say it's a solid 7. There's no areas where the paint is fading at all. And it looks quite good a few feet away. It just doesn't have the "luster" that factory paint would have. But totally not worth repainting the entire car at this point since the paint is still good. But yeah, I get it... restoring a car never makes financial sense. It has to be an action done purely out of sheer love of car, or insanity.

its still going to be very pretty and reliable which is more than can be said for all 3 of the ones that are in "my" fleet

quote Originally posted by cartercarbaficionado: its still going to be very pretty and reliable which is more than can be said for all 3 of the ones that are in "my" fleet

Man, you should see the next car she's working on.

If it was going by at 100 miles an hour, it would look awesome. But looking at it from 10 feet away, you can tell it had a fire. Haha...

It's not a Fiero, but she's going to start on it in the next few weeks.

quote Originally posted by 82-T/A [At Work]: Man, you should see the next car she's working on. If it was going by at 100 miles an hour, it would look awesome. But looking at it from 10 feet away, you can tell it had a fire. Haha... It's not a Fiero, but she's going to start on it in the next few weeks.

is it the vette? the 86 i bought for 300 was also briefly on fire lol. i love gm wiring

quote Originally posted by cartercarbaficionado: is it the vette? the 86 i bought for 300 was also briefly on fire lol. i love gm wiring

Yes... hah... here's a quick video of one of the current problems:




The fire, from what I can tell, had nothing to do with that problem... but the guy apparently wired up a bunch of accessories, like a 12-disc CD changer, an accelerometer that measures G-forces on some kind of gauge, and a bunch of other weird things.

The guy had no concept of fixing things... and merely "added." There are two positive and negative power cables... and there are two "sets" of horns... I don't even know why...

quote Originally posted by 82-T/A [At Work]: Yes... hah... here's a quick video of one of the current problems: The fire, from what I can tell, had nothing to do with that problem... but the guy apparently wired up a bunch of accessories, like a 12-disc CD changer, an accelerometer that measures G-forces on some kind of gauge, and a bunch of other weird things. The guy had no concept of fixing things... and merely "added." There are two positive and negative power cables... and there are two "sets" of horns... I don't even know why...

typical tpi behavior lol.(forgot its the twin tbi setup) never had one that ran right out of...oh 8 now.. jeez im almost 22.. how time flys amiright?
yeah that sounds about right. you either get stock but rotting, high mileage hero/track car, or you get....that

quote Originally posted by cartercarbaficionado: typical tpi behavior lol.(forgot its the twin tbi setup) never had one that ran right out of...oh 8 now.. jeez im almost 22.. how time flys amiright? yeah that sounds about right. you either get stock but rotting, high mileage hero/track car, or you get....that

Yeah, it's Cross-Fire Injection, which should work fine once the TBI units are rebuilt. Biggest problem is all the vacuum lines from that time frame. So she's going to go through and eliminate all the vacuum lines and work backwards. We already bought a new catalytic converter, and we're going to be eliminating the smog pump since it's wildly ineffective and isn't even needed with the newer catalytic converters.

I did already replace the fuel pump and fuel pickup... just because I was getting tired of waiting and I needed to be able to move it around and stuff. The engine has only 50k miles on it (verified), but man... the thing sat a long time with the previous owner.

i bought a WVE sender from rockauto for my 1987 2.5.it read very high too.i replaced it with one from my parts car and the guage seems right now.

Hey guys, I wanted to update this post... it's finally been solved.

It was the sensor!!!

I'm kind of pissed, it was a brand new sensor... I think it was also WVE from Rock Auto... I can't remember the replacement I ended up getting... but while we had the cooling system drained (since we were installing the new radiator, and doing everything else), I went ahead and swapped out the sensor.

We hooked everything back up, filled and burped the system, and drove around without a thermostat (to properly burp the car). j

We drove EVERYWHERE... the car ran so amazing, I can't even tell you. The rear-end was totally tight, and totally solid. The front-end is a little bit floaty... it's the only thing we haven't re-done... so the front suspension needs to be rebuilt, and that's the next thing.

But the temperature gauge... it never went over the 150-160 mark once... (the little tack mark between the 100 and 220 mark). The car ran so cool, and absolutely perfect. So that was the problem the entire time... it was the damned sensor...

Wanted to post a quick update.

We've been driving the car the past couple of weeks. It's especially hot out today, but the temperature on the sensor never got above the 1/4 mark. But... I don't have a thermostat in it right now since we just got it going two weeks ago, and haven't gotten around to installing a new one in it.

Question though. As I was pulling in (picking my daughter up from school in her car)... we saw a little puddle of coolant, just a little bit when we moved the car.

It's definitely NOT from the previous location where we were having all our problems, that's for sure been solved. But it LOOKS like it's coming from the water neck... specifically, I think I may not have tightened the hose clamp down far enough (as it barely looks like it's even depressing the hose on the neck).

Question I have though... I couldn't get it to leak while I was watching it. I let it idle for like 15-20 minutes... not a drop. It's only after a lot of spirited driving. I'm PRETTY SURE it's coming from that hose because we replaced it, since the old one had a gouge in it (from Rock Auto)... and I guess I didn't tighten it enough.

Question though... is it normal for coolant to leak (when there is a slight leak) only during spirited driving, even if the car never overheats? Is it possibly as a result of higher pressure from the water pump since it's spinning at higher RPMs? Just curious. My concern of course is that maybe I have a head gasket leak, but I seriously doubt that... just overthinking things. I just find it odd that it would only leak when we're driving around in high rpms, and when it's idling... not a drop, especially when the temperature on the gauge doesn't show a hair over 1/4.

Thanks!

quote Originally posted by 82-T/A [At Work]: Son of a ***** ... I tightened the hose on the thermostat neck... and drove the car around. it was sitting at 220 for quite a bit, but then all of a sudden it jumped to about 180 on the gauge... and stayed there almost indefinitely... only going to MAYBE 190 when I would be stopped at traffic. Car ran much better and smoother with a thermostat in it (since now it's actually running with proper temperature) and even my gas consumption decreased. I pull into the garage, and the front radiator is just gushing coolant... this is a BRAND NEW aftermarket radiator. I can't even begin to understand what possibly happened here, but I am pissed. I put a pan under it, and it lost about a gallon or so of coolant. This is so frustrating... I don't know if maybe a bolt penetrated it and put a hole in the radiator, or if somehow it just sprung a leak from poor welds... I don't know... but I am pissed. Now I have to take the fan, radiator and everything back out again.

heyyy im not the only one cursed with fiero radiators anymore. welcome to the club so far ive had 8 fiero radiators explode on me 👍
in all seriousness theres 0 quality control on anything anymore so you can try again but i would be prepared for issues again with either it being clogged with manufacturering debris and inspeft welds throughly. there could also be a plug in the side thats leaking since ive had a few rads that used a oringed bolt where the fan bolted in (i do NOT like any 2001 gtp radiators from the aftermarket because they all pull this crap)

quote Originally posted by cartercarbaficionado: heyyy im not the only one cursed with fiero radiators anymore. welcome to the club so far ive had 8 fiero radiators explode on me 👍 in all seriousness theres 0 quality control on anything anymore so you can try again but i would be prepared for issues again with either it being clogged with manufacturering debris and inspeft welds throughly. there could also be a plug in the side thats leaking since ive had a few rads that used a oringed bolt where the fan bolted in (i do NOT like any 2001 gtp radiators from the aftermarket because they all pull this crap)

Yeah... I'm not pleased. Not happy to be in your shitty radiator club! Hahaha... but thanks for making me feel welcome. Haha...

I'm a little nervous too... I'm still getting puffs of white smoke, and I'm thinking there's no beating around the bush... I'm convinced there's possibly a head gasket leak somewhere... possibly where combustion is getting into the coolant passages. If I let the car sit and idle... and I rev it up... it'll get a huge puff of white smoke. But I can go drive it around everywhere, and there will be no smoke. But I let it sit and cool off a little... and magically, a puff of smoke.

I'm going to have to figure this out... but the car runs / drives absolutely amazingly... and no chocolate milk in the oil.

I think the next step is to figure out where it's leaking from the radiator... get the radiator patched (I found an aluminum welding guy who I just dropped off the Solstice intercooler with), and then put on a radiator compression tester to see what's happening. I have to assume that if it spikes like crazy, I have my answer... and then I need to go looking for a new cyl head.

quote Originally posted by 82-T/A [At Work]: Yeah... I'm not pleased. Not happy to be in your shitty radiator club! Hahaha... but thanks for making me feel welcome. Haha... I'm a little nervous too... I'm still getting puffs of white smoke, and I'm thinking there's no beating around the bush... I'm convinced there's possibly a head gasket leak somewhere... possibly where combustion is getting into the coolant passages. If I let the car sit and idle... and I rev it up... it'll get a huge puff of white smoke. But I can go drive it around everywhere, and there will be no smoke. But I let it sit and cool off a little... and magically, a puff of smoke. I'm going to have to figure this out... but the car runs / drives absolutely amazingly... and no chocolate milk in the oil. I think the next step is to figure out where it's leaking from the radiator... get the radiator patched (I found an aluminum welding guy who I just dropped off the Solstice intercooler with), and then put on a radiator compression tester to see what's happening. I have to assume that if it spikes like crazy, I have my answer... and then I need to go looking for a new cyl head.

worst comes to worse i have a fiero duke head sitting on a shelf from the built Duke, i don't think its cracked but theres 0 good machine shops with 150 miles. i can also find you one im sure since im drowning in duke stuff atm

quote Originally posted by cartercarbaficionado: worst comes to worse i have a fiero duke head sitting on a shelf from the built Duke, i don't think its cracked but theres 0 good machine shops with 150 miles. i can also find you one im sure since im drowning in duke stuff atm

Thanks CarterCarbs... I may have to take you up on that. Do you have a need for a perfect 88 cyl head? It's just sitting on the floor of my garage taking up space.

But yeah... I don't think it's the head, but could be the gasket. It could ALSO be the intake manifold... it was pitted a lot by the coolant passage, so it's possible that's happening. I could remove the plugs and check to see if one of them is SUPER clean, that would basically answer my question if I have a head gasket leak, among other things.

It has lots of power though, really runs amazing.

Is it bad to re-torque the head bolts? Just curious... they're already on the car of course... but if I take a torque wrench to them again (90 foot pounds I think?)... will I destroy anything?

quote Originally posted by 82-T/A [At Work]: Thanks CarterCarbs... I may have to take you up on that. Do you have a need for a perfect 88 cyl head? It's just sitting on the floor of my garage taking up space. But yeah... I don't think it's the head, but could be the gasket. It could ALSO be the intake manifold... it was pitted a lot by the coolant passage, so it's possible that's happening. I could remove the plugs and check to see if one of them is SUPER clean, that would basically answer my question if I have a head gasket leak, among other things. It has lots of power though, really runs amazing. Is it bad to re-torque the head bolts? Just curious... they're already on the car of course... but if I take a torque wrench to them again (90 foot pounds I think?)... will I destroy anything?

i retorqued my 289 ford a few times and it was ok? if you need another 84 manifold i got that too. the tb is going in the parts stash since it needs a full rebuild but the intake wasnt bad but we were not spending another dime on dukes for our 84 (if you really want i will trade a 3800 for our entire freshly broken in duke and its automatic and maybe a spare automatic as well if i can find ANNNY 4 or 5 speeds for a decent amount which is like 100 bucks)
as for the 88 head? yeah i could probably put it to good use for the upcoming camaro or 3400 swap we are doing since i have a broken 2.8l head, if its a duke head i know somebody who probably wants a spare