aluminum rad and heater core cooked by overheating?

[350Rocket]

Just wondering if anyone has thoughts on this, I have a nice Griffin Aluminum rad in my 84 Cutlass that was put in 6 years ago when I put the car together. It was a few years old at that time, but anyways, it's never seen salt, had regular coolant changes, a couple years ago it started leaking intermittently. It took me a while to track down the leak as it usually occured only in colder weather, start and end of the driving season. Now it leaks all the time. I also had to replace the heater core last year cause it started leaking, even though it was only about 6 or 7 years old too. Both of these happened maybe a year after I accidentally overheated the engine by forgetting to switch on the electric fans.

The temp gauge was wrapped back around almost to 0 when I realized it (probably 280* plus). I turned the fans on and cranked the heat and popped the hood and let it idle until it was down to normal temperature. It never boiled over. The engine was completely unharmed even with I'm assuming the factory head gaskets from 1975-1976 ish. Do you think the overheat could have damaged an expensive aluminum rad and a heater core, but not cooked the 35 year old never rebuilt 350 Olds?

I'm finally pulling the rad this fall as soon as I park the car for winter, to take it and see if it can be repaired. It sure kept the engine nice and cool as long as I didn't forget the fans. This winter its getting a proper coolant temperature control for the rads too, so no need to lecture me on that 🙂

 

[DRIVEN]

I doubt the heat hurt them. I would suspect a pressure problem. Test the cap to be sure it's actually releasing pressure at the correct spec. You may also have a head gasket beginning to let go. A CO2 tester used in the cooling system can be useful.

 

[350Rocket]

Originally I was concerned about a headgasket issue but its been over 2 years and about 40000kms since the rad leak started and there are no other symptoms. Temperature always runs perfect and I drive it two hours a day round trip to school most of it at 120kmh. I might try the emissions test machine at work but it seems like a waste if time everyone else says if it did have a head gasket going bad it would have done something by now.

 

[pontiacgp]

your temp guage may be off a bit since it did not boil over and 280º shouldn't cause any damage. We've run a SBC with an aluminium rad around the track over 260º with a 28 lbs cap and no problems. Your rad and heater core would not have been damaged. The heater cores have issues with leaking around the tubes, they cheap out on the solder and I've had to fix mine after it was in 2 years. Aluminium may not rust but it does corrode and if your rad is around 8 years old it's lasted pretty good. I'd bring it into a shop and see if it can be repaired

 

[Bonnewagon]

I guess it's a possibility but in all the many catastrophic overheats I've seen, never did a heater core or radiator let go, but they of course were copper/brass. It's more likely a corrosion issue, did you use distilled water in the system when you switched to the aluminum radiator? Was the heater core copper/brass or aluminum, and was it new also? I'm wondering because I too run an aluminum radiator and all my new stuff is aluminum also, but I only use distilled water in those systems. FWIW I just changed out the aluminum heater core on my 80,000 mile '99 Sunfire and it looked good as new, but again, only distilled water and Dexcool was used.

 

[350Rocket]

Yeah, I only used distilled water, as my dad told me about major issues he had once from minerals in the tap water. The gauge maybe off at higher temps but it seems pretty close at normal operating temp, I have a 180 tstat and it runs very close to that all the time. The heater core was a new one in my previous Cutlass a couple years before I started driving this one, so I used it since I had the car almost completely apart. I have a hard time believing the rad corroded that quickly with no winter driving and regular coolant changes. The factory rads last a lot longer than that under worse conditions.

The heater core I can understand it failing early as they don't make the replacements as well as the original. It was not copper/brass, just cheap aluminum I guess.

Either way I'm hoping the rad is fixable, otherwise it will be getting an OEM type, recored rad that was in one of my parts cars, looks to be at least 10 years old.