# Cooling problems



## Hoofer814 (Apr 11, 2020)

Hello all. I am trying to get my 1970 455 QuadraJet engine to get below 200 degrees. I added an fan shroud and replaced a fan clutch with no luck. I was going to try a new water pump and I was thinking an aluminum radiator would be my final step if the water pump didn’t work. And if I get the radiator what brand? I wanted to spend less than $200. Any thoughts? Thanks!


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## Mine'sa66 (Oct 30, 2019)

Are you having any overheat issues? How confident are you in your gauge? Have watched a lot of folks chase a problem that wasn't a problem at all. 200 isn't all that high, particularly if that's as high as it goes under all conditions.
That being said, what are you running for a thermostat? How big is the current radiator? 3 or 4 core? Is the current radiator nice and clean on the inside? Fins all/mostly there?


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## PontiacJim (Dec 29, 2012)

Get a hand held laser temp gun. Gauges can often be inaccurate. Know that it is running at 200 and not that the guage is running at 200. Shoot several areas of the radiator and then top hose and bottom hose. Should be a noticeable difference in temps from top hose, water out, and bottom hose, water in. Do this before tossing any money into the cooling system. Then come back with the results and you can get additional advice as to what to do next.


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## O52 (Jan 27, 2019)

Check your thermostat. 195* was standard from 68 and up. But agree with the above, 200* is nothing to worry about especially with a 195 thermostat


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## Hoofer814 (Apr 11, 2020)

Mine'sa66 said:


> Are you having any overheat issues? How confident are you in your gauge? Have watched a lot of folks chase a problem that wasn't a problem at all. 200 isn't all that high, particularly if that's as high as it goes under all conditions.
> That being said, what are you running for a thermostat? How big is the current radiator? 3 or 4 core? Is the current radiator nice and clean on the inside? Fins all/mostly there?


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## Hoofer814 (Apr 11, 2020)

Thanks for your reply. I should have mentioned the temp hits 230 easily and mostly sits at 220 unless I’m on the highway. Then it’s at 200. I like the idea of a getting a digital thermometer and taking the temp. The gauges are brand new. The radiator is I believe original and appears to have been painted so that is a problem.


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## Hoofer814 (Apr 11, 2020)

PontiacJim said:


> Get a hand held laser temp gun. Gauges can often be inaccurate. Know that it is running at 200 and not that the guage is running at 200. Shoot several areas of the radiator and then top hose and bottom hose. Should be a noticeable difference in temps from top hose, water out, and bottom hose, water in. Do this before tossing any money into the cooling system. Then come back with the results and you can get additional advice as to what to do next.


I like the idea of taking the temp of the various components. The radiator could be the original and appears to have been painted which is a problem. Would it make a difference if it was the original for a 326 which is what the car was built with. Maybe not big enough for 455.


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## pontrc (Mar 18, 2020)

At least a 4 row radiator which came with big block cars especially with ac


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## PontiacJim (Dec 29, 2012)

pontrc said:


> At least a 4 row radiator which came with big block cars especially with ac


Unless you go with an aftermarket aluminum radiator. Depending on row count and tube size, sometimes 2 rows can be enough. So I would agree the radiator may be a bit small.

You mentioned new gauges. Factory? If the gauges are not calibrated with the sending units, or you don't have a matched pair, then they may not be corresponding in their values and give false readings. This is one reason for the hand held laser temp gun so you will know how accurate your gauges are.


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## Mine'sa66 (Oct 30, 2019)

Hoofer814 said:


> Thanks for your reply. I should have mentioned the temp hits 230 easily and mostly sits at 220 unless I’m on the highway. Then it’s at 200. I like the idea of a getting a digital thermometer and taking the temp. The gauges are brand new. *The radiator is I believe original and appears to have been painted so that is a problem.*


Bingo! I'll bet the fins are all nice and black...probably glossy too right? Can't paint those, sounds like you know this. Still, before you change anything, confirm the temps via another measuring device. As mentioned, infrared or laser themo are a good way to see what's going on. Warm at idle, cooler at cruise is usually flow or inefficient exchange and it sounds like we know which . A factory 4 core radiator should be all you need. Lot of people running around with 3 cores with good fans/shrouds too. Aftermarket aluminum setups are awesome, but it's overkill for most applications.


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## Hoofer814 (Apr 11, 2020)

Mine'sa66 said:


> Bingo! I'll bet the fins are all nice and black...probably glossy too right? Can't paint those, sounds like you know this. Still, before you change anything, confirm the temps via another measuring device. As mentioned, infrared or laser themo are a good way to see what's going on. Warm at idle, cooler at cruise is usually flow or inefficient exchange and it sounds like we know which . A factory 4 core radiator should be all you need. Lot of people running around with 3 cores with good fans/shrouds too. Aftermarket aluminum setups are awesome, but it's overkill for most applications.


It does look glossy so I think that's the issue. I will check the temps for sure to see how accurate the gauges are but I think they're good. Thanks for the great advice!


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## Mine'sa66 (Oct 30, 2019)

Hoofer814 said:


> It does look glossy so I think that's the issue. I will check the temps for sure to see how accurate the gauges are but I think they're good. Thanks for the great advice!


Seen it 1000 times. Paint is a good insulator, glossy paint even moreso. Your fins are not only coated with insulation now, the space between them has been reduced by 2x the paint thickness as well. Confirming gauge readings is always a good idea, but unless that radiator had an abundance of unused capacity, it's going to have to go if the core is painted. If it is a nice 4 core factory radiator, it might be worth it if you have an oldtime radiator shop in your area to have it re-cored.


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## Hoofer814 (Apr 11, 2020)

Mine'sa66 said:


> Seen it 1000 times. Paint is a good insulator, glossy paint even moreso. Your fins are not only coated with insulation now, the space between them has been reduced by 2x the paint thickness as well. Confirming gauge readings is always a good idea, but unless that radiator had an abundance of unused capacity, it's going to have to go if the core is painted. If it is a nice 4 core factory radiator, it might be worth it if you have an oldtime radiator shop in your area to have it re-cored.


It's really strange because the guy i bought it from was a real car guy. Took great care of it so i'm not sure why he painted it other than to look nice. I opted to order a 4 row aluminum radiator. I think that will do the trick. Thanks for the feeback!


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## JohnCarnell. (Aug 11, 2019)

Hoofer814 said:


> Thanks for your reply. I should have mentioned the temp hits 230 easily and mostly sits at 220 unless I’m on the highway. Then it’s at 200. I like the idea of a getting a digital thermometer and taking the temp. The gauges are brand new. The radiator is I believe original and appears to have been painted so that is a problem.


I have exact same issue with my 68 with a moderate cam. I have put in new aluminum radiator with fan, new water pump. Also replaced plates behind water pump with stainless plates. Reformed plates so that propellors are only 1/8th inch or so from plates so there is no chance of fluid bypassing being pushed thru to radiator. That lowered the temp by approx 10 degrees. Now runs at at 195 except on 80 + degree days or idling in traffic then it will also approach 220 and once in a while 230 but never boils over. Several top notch mechanics have told me to not worry about it. They feel it will always run at that temp with todays fuels and having electronic ignition. So.......highway crusin in hot weather seems to be part of my solution not idling around town. May not be a total solution for you but has so far worked for me.


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## Lemans guy (Oct 14, 2014)

Are you running a thermostatic fan clutch or electric fans. Cool operation while at highway speed and hot at idle is a classic sign of a weak or bad thermostatic fan clutch....if you have one


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## PontiacJim (Dec 29, 2012)

We have also seen where timing issues were the cause of a hot running car. Gotta have the vacuum advance working, initial timing set correctly (which means a little different than factory when using a bigger cam) and setting up the timing curve.

Running lean will also cause the engine to run hotter. The ethnol laced gas can run leaner and making a jet change could help. Here is where an O2 sensor or a shop that is able to monitor O2 can help. Hot underhood temps, from what I have read, can also lean out the A/F ratio.


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## Hoofer814 (Apr 11, 2020)

Hoofer814 said:


> Hello all. I am trying to get my 1970 455 QuadraJet engine to get below 200 degrees. I added an fan shroud and replaced a fan clutch with no luck. I was going to try a new water pump and I was thinking an aluminum radiator would be my final step if the water pump didn’t work. And if I get the radiator what brand? I wanted to spend less than $200. Any thoughts? Thanks!


Hello everyone. I purchased a 4 row aluminum radiator from Champion and installed it last weekend. The old radiator was definitely done. It runs at around 200 now around town but drops to 180 on the highway or speeds over 40 so it's better. I also installed a 165 tstat but realize that was a mistake. Going to switch out to 185. Also, I need to fill the gap between the shroud and the radiator. Any suggested material to use?


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## O52 (Jan 27, 2019)

Go to Home Depot or Lowes and get the peel and stick foam insulation that comes in a roll. Size it to fill your gap and place it between the shroud and radiator.


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## Hoofer814 (Apr 11, 2020)

O52 said:


> Go to Home Depot or Lowes and get the peel and stick foam insulation that comes in a roll. Size it to fill your gap and place it between the shroud and radiator.


I was thinking that was the way to go but wondered if it might melt. I’ll see how it works out. Thanks!


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## Mine'sa66 (Oct 30, 2019)

Hoofer814 said:


> I was thinking that was the way to go but wondered if it might melt. I’ll see how it works out. Thanks!


There's a few different kinds. You want the real stiff stuff. Almost has the strength of a shingle. None of them will melt, the softer stuff will not stay in place. Your fan is making a tornado in there!


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## PontiacJim (Dec 29, 2012)

Hoofer814 said:


> Hello everyone. I purchased a 4 row aluminum radiator from Champion and installed it last weekend. The old radiator was definitely done. It runs at around 200 now around town but drops to 180 on the highway or speeds over 40 so it's better. I also installed a 165 tstat but realize that was a mistake. Going to switch out to 185. Also, I need to fill the gap between the shroud and the radiator. Any suggested material to use?


200 degrees? Are you going by the gauge or did you shoot the radiator/cooling system with the laser gun you bought?


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## Jetzster (Jan 18, 2020)

Mine'sa66 said:


> Seen it 1000 times. Paint is a good insulator, glossy paint even moreso. Your fins are not only coated with insulation now, the space between them has been reduced by 2x the paint thickness as well. Confirming gauge readings is always a good idea, but unless that radiator had an abundance of unused capacity, it's going to have to go if the core is painted. If it is a nice 4 core factory radiator, it might be worth it if you have an oldtime radiator shop in your area to have it re-cored.


Mine’sa’66 ques hey what about this paint
It sez it’s special for radiators, would this be ok to use or no?thx


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## Mine'sa66 (Oct 30, 2019)

Jetzster said:


> Mine’sa’66 ques hey what about this paint
> It sez it’s special for radiators, would this be ok to use or no?thx
> View attachment 135985


Never used it, but it seems the folks that invented it are aware of the issues. If I had a need to paint a radiator and I discovered that product, I think I'd give it a go. Are you thinking of painting your new radiator? if so, be darn sure this stuff is ok on an aftermarket aluminum radiator.


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## Jetzster (Jan 18, 2020)

Roger that, Mine, I toyed with using this paint a few months back on the toptank when I ordered a 17” cold case, supposedly per their ‘specs’for a ‘64 ,but the rad didn’t fit the thickness in my mounts like thay said it would , and so when I called them to complain ,the cold case fix Was for me to swap my engine outlets sides and they would send a thicker one , so I said no ,and sent it back, instead I got a drop-in new hi-eff OEM desert cooler 4core from Ames. Which seems to have come with some paint on the fins, hopefully it’s correct paint, glad I went that way instead more$$$ but ,it looks eracorrect and works well ..


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