Need some help, just had car serviced

[D TR41N]

So my heat stopped working the other day and my car overheated. It got about 3/4ths up and I shut the engine off and had it towed to a service shop. They said they replaced the thermostat because it wasn't opening and that they also wanted to check out the radiator and water pump but I said no because they said it would take 5 hours and at $90 an hour its not worth it to me since the car is going into storage. Anyway I picked the car up today and started to drive it home and my heat didn't work again and the car was beginning to overheat. I started taking back roads at 25mph and the car was fine, staying in a decent temp range. Then about halfway home of the 20 mile drive, my heat started working and my overheating stopped I could go as fast as I wanted no issues. My question is, do you think the guy at the shop is just bullshitting and didn't really replace anything even though he said he replaced the thermostat? Shouldn't the heat have been working after a thermostat replacement? Plus the bolts on the thermostat don't look like they have any wrench marks on them and considering the car is 20 years old the chances of those bolts being removed recently are slim so you'd think that marks would be present. Is there a way to check for sure to see if he replaced it or something? Or could my heat be working intermittently for another reason?

 

[MadNad]

The fact that heat starting working at some point and the car quit running hot seems that either the thermostat actually finally opened, or something came loose that was clogging the cooling system...like maybe a clogged heater core. Would be a good idea to flush the system if you haven't in a while. I doubt your water pump has failed, unless the blades have corroded away and/or the bearing has failed.

My heat quit working because of the heater vsv had failed ( http://www.rclambert.com/supra/vsv.htm ). This seems to be common on supras. You can replace it or bypass it. That being said... eventually I found out that my overheating issues were because my headgasket was on its way out.

 

[D TR41N]

Thanks for the info. No one around here seems to flush radiator systems. Everyone just drains and fills. What exactly is a radiator flush anyway? Its when they hook it up to a pressurized tool and try to flush out all the gunk that may be stuck in the rad?

 

[BlackDynamite]

You could pay someone to do it. I just unhook the bottom hose from the radiator and the top one also. Run a water hose into the top of the radiator and let it run for a few minutes. Then i would take the thermostat housing off(check your thermostat while you're here :] ). Turn on engine and run a water hose down neck into the engine.

But that's how i do it. There prolly is a better, more professional, way to do it.

 

[Nomad707]

i do it almost the same.. kinda. i just drain all fluids, fill it with water, and run for 5 minutes open loop, drain, repeat 3 times total, then refill with proper coolant/water amount, and reinsert thermostat