I have a 1986 GL10. It sat for about 3 years with a broken timing belt, in extreme washington weather. I recently got the title signed over to me and had it fixed. It has been running great with one exception. It overheated once. I filled it up with coolant, and it runs great again. But now that its getting colder, I need the heater to work. It doesn't. It blows air, just medium temperature. Any ideas? I am thinking a sticky thermostat? Thanks
Get the engine up to operating temperature and then touch both heater hoses. If both are hot to the touch then this rules out an air pocket. The controls are vacuum operated. Check that white cannister under the hood over on the passenger side of the firewall.
Hi,
The fact it overheated once since you've gotten it back together tells me there may have been air in the system. Heater cores are generally higher than most of the rest of the engine, so there could still be air in there.
After doing the checks already suggested to see if the hoses are hot on both sides (if I'm not mistaken, you car has a "constant flow" heater core, w/ heat to the cabin controlled by the vacuum linkages mentioned), you can try this drill:
Disconnect both heater hoses. Run water at pretty good pressure both ways thru the core to make sure you ARE getting good flow. Then hook up ONE hose to the core. Make sure the end of the other one's close to its connector, but leave it disconnected for now. Take a small length of appropriate sized hose and hook to the other side. Remove the rad cap.
Now, get a funnel and put it in the open end of the disconnected hose, then begin to fill the system "backwards" while trying to keep the funnel at a point higher than anywhere else in the system. If you start getting coolant flowing out the radiator cap fitting, install the cap. Then, when you start seeing coolant coming out of the temporary hose, you can take it off and hook up the real one. Jack up the front of the car as high as you can, take the radiator cap back off if you had to install it, and run the engine at idle w/ the heater on full to finish burping the system. Turn it off, let it cool for a while, then refill the radiator as necessary and install the cap. Sometimes it takes a few "burp" cycles to get all the air out.
Sticky t-stat? Does the temp gauge register in the normal range? Does the upper rad hose get nice and hot? If yes on both, the t-stat is PROBABLY working ok, but since the car's been sitting so long, it wouldn't hurt to install a new one. OEM is best there!
Good luck!
Rick
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.