Radiator, Overflow Reservoir - Want to Sell
 

So here's the deal...I'm having enough problems with my supra that I decided to sell it. But something funny is going on with the radiator. Sometimes it will just overheat temporarily. When I stop the car, the overfill reservoir for the radiator is completely full. The next day when everything has cooled down, it is empty. I replaced the radiator cap a couple weeks ago, but clearly that didn't fix the problem.

It sounds like (from the forum) that this could be a thermostat problem, or a blown head gasket. What kind of repair costs could that be for me at a mechanic and should I just try and sell it without bothering to fix that?

Well an overflow is supposed to fill up at least partially as it heats up, then as it cools, their is suction back into the radiator. Thats why there is a hot line and a cold line on the overflow reservoir. does it overflow and blow out steam and all that neet stuff? the radiator cap keeps the system at presure - which raises the boiling temp of the coolant.

I don't ever see steam coming out, but the temp gets close to the red on the gauge sometimes, and in those times it seems like all of the coolant is in the resovoir and not in the radiator.

Hi!
Sounds as though your system is working properly ( sucking water back into the radiater ) ,BUT! -- have you checked the timing lately , -sounds as though the engine is running a little retarded ,does it feel sluggish? -- this raises the engine temperature to run a little hot and blow the water into the reservoir , try advancing the ignition and see what effect that has .If your engine is a 7mgte , then undo the clamp nut and turn the cam position sensor ANTICLOCKWISE ( as viewed ) to ADVANCE the ignition , best done with the engine running -- this should increase the engine revs to peak ( ideal ) and then drop-off ( too far advanced ) . Turn CLOCKWISE to slightly RETARD the ignition to peak again ( ideal ) and lock up the clamp.

Do not just blindly adjust the timing. Use a timing light and follow the procedure in the service manual. Also check that the mechanical timing is spot on as well. A blown head gasket is a definite possibility but start out with the easy/cheap stuff first.