Overheats when driving?

Hi,

Thanks for the update. I'm glad you got it figured out and it isn't overheating.

Take care and feel free to come back anytime in the future.

Joe

Hi guys. One thing I haven't seen mentioned yet is the cooling fins on the radiator. They became badly corroded on my '88 Grand Caravan causing the engine to run hotter than normal, but only above 60 mph and only when outside air temperature was over 60 degrees. I went from Wisconsin to Colorado, to Missouri, then back home like that. It never was hotter than 40 degrees outside, so the engine never ran hot until next spring. The cooling fins on the lower quarter of the radiator were either gone or would crumble away with the slightest touch. They acted like a rotten chocolate chip cookie.

Bar's Leak isn't going to help. No mention has been made of losing coolant. That product is meant to stop leaks, most commonly from radiators and water pumps.

While I've never run into this myself, I've been told there are some cooling system designs that, to work properly, require flow through the heater core. I suspect it has something to do with directing the flow of coolant to the thermostat. Regardless, if the heater core is leaking, I would connect the hoses together, not cap them off.

I'm anxious to learn the solution.

Fin corrosion can cause this, but I've seldom seen it on the trucks, lots of it on the vans though. The sealer was because of the chemical test he did showing some combustion gases in the coolant. If it is a minor leak, it might be caught in time. I don't use bars leak these days, unless it's an emergency type fix, I have seen far too many cooling systems trashed because of the leak stop fillers they use. The Blue Devil is strictly water glass. (Same stuff they used to wipe out the cash for clunkers cars) I've never had it plug up a system because it only reacts to heat and air contact.

If it isn't running hot, I would probably swap the radiator out but not run the sealer unless it starts acting up again.