Hi all, over the last year or so, I have been doing a bunch of preventative maintenance on my 80 (cooling system refresh/replace, exhaust, few other thing).
Ever since replacing the radiator, thermostat, water pump, and all cooling hoses, it's been weird about the thermostat opening when it should/heat coming on. At first, the thermostat was definitely broken. Replaced that and other parts and it still did it. Replaced the thermostat twice, determined it wasn't that. Had it back to the shop for weeks to diagnose. Finally came back that it was a hose that had gotten sludge in it -- toward the back, hard to see, etc.
Anyway, finally got it back after doing the rear main and a few other things and I'm getting ready to sell it on Bring a Trailer. Today, as I'm out snapping pictures and letting it run to charge the battery (not my daily driver at this point), I notice the heater/thermostat/etc. is STILL doing the same thing by not opening. Here's the weird part...
I revved the engine up to about 2-3k RPM (from idle) and heat began coming through. Needless to say, I was pissed. But what I noticed was that after I let my foot off the accelerator pedal and the engine went back down to idle, the heat STOPPED. Press on the pedal, heat comes back.
Obviously now I'm pretty confused, but what's worse is I'm trying to sell it and I won't sell it if it's got an issue like this because I don't know what it is. Is it coolant system hardware or leaks? Could it be the head gasket??? Any other ideas?
Any help would be *greatly* appreciated!
Ever since replacing the radiator, thermostat, water pump, and all cooling hoses, it's been weird about the thermostat opening when it should/heat coming on. At first, the thermostat was definitely broken. Replaced that and other parts and it still did it. Replaced the thermostat twice, determined it wasn't that. Had it back to the shop for weeks to diagnose. Finally came back that it was a hose that had gotten sludge in it -- toward the back, hard to see, etc.
Anyway, finally got it back after doing the rear main and a few other things and I'm getting ready to sell it on Bring a Trailer. Today, as I'm out snapping pictures and letting it run to charge the battery (not my daily driver at this point), I notice the heater/thermostat/etc. is STILL doing the same thing by not opening. Here's the weird part...
I revved the engine up to about 2-3k RPM (from idle) and heat began coming through. Needless to say, I was pissed. But what I noticed was that after I let my foot off the accelerator pedal and the engine went back down to idle, the heat STOPPED. Press on the pedal, heat comes back.
Obviously now I'm pretty confused, but what's worse is I'm trying to sell it and I won't sell it if it's got an issue like this because I don't know what it is. Is it coolant system hardware or leaks? Could it be the head gasket??? Any other ideas?
Any help would be *greatly* appreciated!