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Discussion Starter #1
I have a 67 GTO, with a 68 engine in it. It has the usual hot idle issues. Runs at 190-195 when driving, so its fine when moving. Just goes up when stopped. I have read most of the other threads on hot idle, so I understand some of the causes and the steps to take. I have a high flow thermostat on now. I've tested out a buddies fan that's much better than the one I had in, and still have the same thing. Haven't touched the water pump yet, but thats on the list eventually, but looking at radiator options for now.

I was just curious to get feedback on radiator brands that others have used that they are happy with. Any thoughts or feedback would be appreciated. Thanks!
 

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Not sure that I can help I also have a 67 but the radiator is stock. But make sure you measure out the one you have now there are 2 different sizes. Measure the radiator and the support


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I went back thru yr posts and looked at the photos. Nice engine room transformation. I have a '67 4sp with A/C. I bought an Ames regular 17 1/2 4 core desert cooler years ago. https://secure.amesperf.com/qilan/Detail_Web?part_num=P119AL&order_number_e=MzY5MDQzOQ== &web_access=Y Now it seems that they have a number of more expensive options. Unlike yours, my engine gets hotter as speed increases. A number of reasons for that. Anyway it looks like you have an aftermarket flex fan and you tried another but no help. If you scroll down the items in this link, you'll find fans, shrouds, and clutches. https://secure.amesperf.com/qilan/Search_Web?order_number_e=MzY5MDQ0Nw== &method_1=&method_2=Y&search_method=2&cat_rowid=1&search_year=1967&search_keyword=fan&sort=0
Buying all this could get expensive with no guarantee of success. I have the desert cooler, fan shroud, heavy duty clutch, and 19 in 7 blade fan. Even here in Houston, I have no problem idling. Though it might take some time, I would start with just a shroud. Allows for more air to pull thru the radiator and not that expensive. If you get some improvement and wants more, then I would add the fan and HD clutch. I would hesitate about investing in an aluminum radiator. My sense is that it might help my problem but not yours. Hopefully some more knowledgeable folks than me will chime in.
 

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OK, assume you read the "Sticky" in the Tech section on overheating. Several times on these forums it has turned out to be the water temp sensor as the "generic" ones from your local parts store seem to give a false reading when in fact your temp may be OK. Getting one from a Pontiac parts supplier will get you a good one. Simple checks are to make sure the fan is not to far from the radiator, use a good flex fan and fan shroud (this improved my cooling), and use a 160 T-stat (We have had a number of owners say the "new" T-stat was bad and when a good one was installed, temp was good). No doubt you read about the water pump and plates as being a problem as well.

Ever try throwing on your heater on high when it starts to climb? This may burn you out of the car, but can work as the heater core acts as another radiator in a pinch.

Getting a new radiator can't hurt, but it may or may not solve your cooling problem. I did some research on aluminum radiators and what I found is that the larger core tubes transfer heat (cool) better than smaller ones. Different manufacturers offer differing sizes. For example (this is not accurate, just off my head) you may see an ad for a 2 row radiator having 36 of the larger diameter tubes while another guy advertises a 2 row radiator having 48 of the smaller diameter tubes. You might think the 48 tubes are better and should cool more than 36 because there are more of them, but in fact, they may cool less because the 36 tubes have a larger diameter and throw off more heat, thus cool your engine better. Something to consider.

The factory had both a 3 row (2" upper & lower tank) and 4 row (2 7/8" upper & lower tank) radiator. Each radiator has different brackets. So if you were to move up from a 3 row to a 4 row radiator, you will have to install a new set of radiator brackets, rubber insulators, and for 1967, the upper radiator bracket that goes over the top of the radiator. These are all available aftermarket, so not a problem to get if you want to go with a factory type radiator. But whatever radiator you select, aluminum or factory type, keep in mind to know what size tanks you will get and if it will work with the available radiator brackets for an easy bolt in.:thumbsup:
 

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Griffin aluminum solved my overheating problems....pricey but it works great.
Took my 68 400 HO radiator to an old timey radiator place. They took it apart rodded it out and cleaned it completely. Said it was about 50% plugged up. Looks brand new since they finished it. Took the water pump apart ( not leaking ) and found one of the two plates in the back of the pump was missing. Replaced plates, new hoses, thermastat and cap. Runs between 170 - 180 here in Florida this summer. That is with the AC running. Had it out yesterday ---- sweet. All just basic maintenance God luck with yours.
 

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Discussion Starter #7
Thanks everyone for the input. I do have a shroud on it , though I hadn't put it on yet in that picture of my engine compartment you saw. Unfortunately I had a voltage regulator go bad and it boiled my optima battery and some of the liquid squirted out and screwed up some of my hard work. Nothing that can't be fixed, but a bummer after all the hours spent cleaning, and sanding and painting.

I know the Griffin and Be Cool type radiator brands seem to fix the problem easily but are pricey. Not sure there is a Griffin under 550. Ames carries the US Radiator Desert Cooler brands, and their aluminum radiator is 369. I'm thinking that route unless anyone thinks it absolutely worth the extra money to jump up to a Griffin. That plus putting in a clutch fan will hopefully do the trick...
 
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