I drove my car this week (Houston, TX) and the outside temp was in the mid 40's. it was my first time to drive it where I needed the heater to keep the windows clear, unfortunately, the heater was not very hot only slightly warm. During the restoration I recored the copper/brass heater core and installed a new heater control valve (AC car). The heater hoses were warm to the touch (not hot) so it seems like the heater control valve and heater core are working.

So, here is my question; I currently have a 180-degree, high-flow thermostat from Mr. Gasket. Would I get more heat inside the car if I installed a 195-degree thermostat? Does the thermostat temp have any impact on cooling performance? South Texas summers are pretty hot, I don't want to create a cooling issue. Thanks,

Rodney

 

I would check the vacuum at the heater valve to ensure it is working correctly and matches the dash control position. The heater hoses should be as hot as the radiator hoses.

 

A180 should be more than enough to feal good heat. I would look else ware, heater valve, or blockage, cables something.

 

Yes thermostat temp rating affects heater air temperature. As stated 180° should be sufficient, With the engine fully warmed and the heater on, one of the heater hoses should be hot and the other a little cooler as heat is dissipated when coolant flows through the core.

 

Aftermarket vendors are usually incorrect with their listings for Olds heater control valves. Your car should have a valve that is normally closed and opens when vacuum is applied. Newer Oldsmobiles use a valve that is normally open and closes when vacuum is applied. If you have the later style valve, it will be closed with heat on, causing your problem. Verify that you have the correct valve and that you have vacuum on that hose when the heater is on.

 

Thank you to all for the comment and good suggestions.

Rodney

 

It's not uncommon for some coolant to flow even when the valve is closed, so don't rely on "warm vs cold" hose to determine if the coolant is flowing. I'd get the engine up to temp then hook a hand vacuum pump to the heater valve and see whether atmosphere or vacuum opens the valve then compare to what the valve is actually getting. That hose coming out the valve should be HOT.

 

Living in the land of -40+ temps, yes it does affect heater temps. As someone who drove Oldsmobile powered cars in trucks in severe cold, proper thermostat operation is key. For your temps, 180 should keep you toasty. Even with a 160, my 70 puts out plenty of heat in temperatures that cold. Honestly the leaky fresh air countering the heat is much more of an issue. My car is non A/C, so valve operation isn't a factor for me. Point a temp gun at all the points and double check the valve operation. It could be a failing thermostat, some do partially fail open or become weak. Good luck.

 

Thanks for the lesson on different heater control valves, Joe.

One thing not mentioned yet is the air mixer door, if it is not closing off the cool air completely and only passing warm air from the heater core, that would reduce the temp felt at the outlet vents. Its been too long since I've owned an A-body w/ AC, so I don't remember if these are controlled by cable or vacuum motor. Non-AC cars use cables.

 

AC cars use a cable as well.

 

Yup, you should feel and hear the rubber "thump" at each end of the cool/hot travel.