Im pretty sure i have a 84 d50 in my 1987 mazda p/u. Im not getting heat to the heater core and not sure where to start. Im planning on running water through the heater core ports tomorrow to see if the core itself is plugged but im not sure if the guy who did it even hooked it up correctly. another question i have regards the thermostat, Ive replaced it twice thinking it was bad but the motor isnt coming up to temperature. I know i need to replace the radiator because it is tweeked so that could be part of my problem but its bubbling back up when filled all the way and comes to running temp. one more thing is im not getting the power i would expect from my motor. its a fairly fresh rebuild with a redline webber. im not sure if this guys swap skills are to par but i have a lot of questions and i would appreciate all the help i could get. ill post pictures on my profile if that will help. this truck still runs paid 700$ for it and i love it. thanks guys
OK so you changed the T stat and it won't come up to temp. Is the fan clutch stuck and not spinning free?
Also if you run it you should be able to feel the upper hose and it should be hot.
Once it's full of water and you start it, it should suck down a little water. Then as it heats up and expands it should spill out a little. Is that happening? But it could be that the core is plugged or the control valve is broken.
ok well i did a lot yesterday now its blowin warm air and the motor still isnt coming to temp.
Is the water temp not coming up or is your gauge not saying its at normal temp? Could be a problem there with the gauge. 2 what temp thermostat are you buying, they come in different temps for different applications. 3 if you did not bleed all the air out of the system that can cause your issues as well.
Ya, I agree...
sounds like a gauge to me too! Usually the trucks don't need a cooling system burp, but anything is possible.
Could open radiator cap as it returns the warm water after fresh start to make sure it pumps ok, if it is doing right, then gauge not working or it got disconnected on the plug at engine block under distributor area. Make sure that wire is connected to the block sensor plug for gauge to be activated
feel the radiator hose then feel the heater hose. If there not the same temp then the heater core is plugged up.
I have seen the pipe that goes to the back of the block get plugged.
If you can get hold of an infrared temp gun you could check to see what the actual temp of the motor is. I would think most service garages would have one now as they are not very expensive any more. Just point it at your thermostat housing and pull the trigger .If your getting 190 or so I would check that the control rod for the heat control is opening the valve all the way. If the dash has ever been removed, the control rod may have been put back in the clip a little too far forward. This would not allow the heat control to open the valve all the way. I made that mistake the first time I had the dash out.