Ok, I recently reconnected my heater core on my 83 GSL and I get plenty of heat until I drive for too long, then it cools down on me to about half as warm as it was while sitting still. The hoses are routed correctly as far as I know, so it shouldn't be a flow problem.

I just can't remember where/what the restrictor looks like, but I know there used to be one somewhere. And I can't remember what the cut off year was for the water control valve/flapper door or if you can tell which one you have without digging too far into it.

Any ideas?

~T.J.

 

Nothing? Really? You're all stumped? Haha

~T.J.

 

I'm watching this as well, I need to learn about this restrictor. I have a problem with my heat control. I cannot seem to regulate the heat so to get warm air. I get either cold or hot but never warm. So it sounds like I may be missing the restrictor. So I'm waiting for someone to chime in along with you.

 

I believe the restrictor is on the 84-85 with the bee hive oil cooler.
I thought all 1st gens had the coolant valve behind the heater core? I replaced the one in my 81 recently.

This is the suction line from the water pump/rad to the heater core from an 84, the restrictor leads to the oil cooler.

 

Thats correct, the valve is under the dash, on the left side of the heater core. I don't know about the restrictor, I'm not even sure that my 79 ever had one, don't know about a 84 or 85, never had one.

 

Thanks, a picture is worth a thousand words! It seems the restrictors job was to divert the majority of the coolant through the heater core, and/or to slow the flow through the cooler to give the water more time to absorb more heat from the oil.

If this is the case, it being missing from mine isn't going to be my problem since I have that pipe going straight to the heater core (without the tee), then out of the heater core into the block where the beehive would have dumped into. I was thinking I needed the restrictor on the line feeding the heater core to slow down the flow through it and allow it to regulate the temp better...

As for the heater valve, I was under the impression there was a cut off at some point where there was no longer a physical water valve and it was simply a flapper door for either hot air or cool air? Maybe I'm remembering wrong. I have worked on a lot of cars over the years.

I just don't understand why the car's temperature fluctuates so much while driving and it cools down so much to nearly blowing cold air when cruising on the highway. The thermostat is new, and I tested it and the old one in water on the stove, both worked perfectly. Granted it's been 10 years since I regularly drove this car, but I seem to remember the temperature being more steady like a "normal" car once it warms up.

~T.J.

 

there is no separate part, the restrictor is built into the pipe between the body and the radiator.

i'd check your thermostat

 

SA's do not have this restriction - the right-side coolant transfer pipe has full-diameter openings at both ends.