: Is this a radiator issue? (a bit long)

Mason H
10-02-10, 02:28 AM
If i am cruizing around town the temp gauge in my '75 will stay at about 190-205 degrees but if i take it on the highway it just keeps climbing.

I tried to take it to Prescott AZ, about 100ish miles away, last weekend and when i got about 40 miles away on I 17 it was at about 245 degrees. So i got it towed home, replaced the thermostat and the lower radiator hose because that was REALLY swollen. Someone didnt replace it when it happened before i owned the car obviously. I tried a second time to go to Prescott but ended up pulling over about 5 miles from where i first did. Temp was at 235. I let it cool and drove back home.

I am thinking i need to get my radiator rotted. There is coolant flowing but maybe not enough? When i take the radiator cap off i an see some hard water/calcium deposits.

Anyone had this problem before, if so what fixed it?

10-02-10, 02:55 AM
The temp light wont come on til 260ish but good call on towing it home, overheating would have been the last thing you want happen. With the radiator, might as well do the water pump and a flush just so you know its all done.

Mason H
10-02-10, 11:18 AM
Well i dont think it is the water pump because it is flowing coolant. Just maybe not cooling it enough do to all the hard water deposits in the radiator. And i planned on flushing and replacing all the coolant.

10-02-10, 08:46 PM
If your radiator is corroded, you should replace it to keep the rest of your cooling system healthy. But usually, if it's not leaking, the radiator shouldn't cause problems with overheating. If the water pump is still circulating the coolant, and there are no leaks coming from the pump housing, then that's probably not your problem either. The first parts I would replace would be the radiator cap and the thermostat; start there fist and keep your eye on it.

10-02-10, 10:31 PM
I had the same problem on my '68 cdv. Stayed cool around town, but kept running hotter and hotter on the freeway, especially going uphill. Your radiator is more than likely plugged and if its original, will need to be replaced.

10-03-10, 08:35 AM
If your radiator is corroded and you flush it, it will probably end up leaking. Start with the cap though.