So I couple days ago I decided after 350-400 easy miles I would give the engine a little get up and go. So about 50-75% pedal nothing to extreme on the rpms and after that I had a few things happen. A belt starting squeaking which was caused by the alt belt loosing *tightened*, master cylinder started leaking *part on order*, and started overheating if I run anything higher then 65mph. Even after I fixed the alt belt today it still over heated on a quick 5-10 min run of holding 80mph. The gauge jumps around a little it seems and if it is running a little hot and I turn everything off then put the key onto the on possition it will jump to 1/4 temp and sometimes slowly start ticking its way to the heat it was displaying before I turned the car off. Also the little ac fan or what ever it is hardly ever turns on. Has a new 180 degree therm stat. Sorry for the rambling just listing anything that might be relevent.
How is the rad cap? Have you had to add coolant? How is the rad/water pump? Fan clutch in good condition? how is the wiring to the sensor on the t-stat housing (you mentioned it jumped around...that's unusual...it could be a simple wiring problem)
The cap seems ok. I have no way of testing most of anything or I know of no ways. The fan had good tension and I am not sure about the water pump. I sometimes can hear water flowing in the hose I had to route over the engine but I dont always hear it. The hose goes into the firewall and usually connects on the driver side but I didnt see that the driver side was capped via metal prior to dropping the motor. Is there anyway to test the water pump? If I take the rad cap off and turn the car on I can see the fluid flowing is that an accurate way of telling anything? I know the wiring is a little schetch it seems but that wouldnt cause it to over heat with actuall signs of over heating would it? I have a green with red line wire hooked direct to t-stat and a yellow with green if I recall correctly to the other area under the green pigtail connector.
Depending on engine load and conditions the fan will engage at some times to cool the radiator. In the front of the clutch fan there is a coil loaded thermostatic bimetal coil that will engage the fan based on air temperature passing by the fan blade. On many older Supras after many miles the seals around the temp coil will start to seep the viscous oil from the fan clutch assay, after the loss of the oil over time the clutch fan goes on holidays and your motor gets the added benefit of about 4 hp and no fresh air intake. One of the symptoms of this problem is a floating temperature gage.
Now, they can also leak and seize up which will cause it to spin at full speed all the time, meaning it'll sound like a hurricane. Probably not the issue you're having.
Yeah I know the fan I have on there now had more resistance but also had some black crud on it as well. Should the fan engage when on the freeway? It says not on that site. Because I know it does kick on when I start the car or if driving in town. I just have to get to the bottom of this soon because I am supposed to be moving on Saturday.
Well I seem to be spiraling backwards! Granted I havnt driven it at all so I dont know if anything is working the same but.. I now overheat running at idle. I went to flush the system and after around 15 mins of running or 10ish after reaching running temp I started to overheat. Same thing on the rinse part of the flush, after filling it back up with coolent, and today after replacing the thermostat again and putting on a new rad cap. I would like to think that its the wiring because it doesnt gradually increse in temp it sits at 1/3 temp and after some time it decides it wants to start over heating and then goes up decently fast for just idleing. The only other thing I kind of thought about would be that maybe the flush caused it to gunk up somehow and now my radiator is clogged. I checked the top hose and it was decently warm/hot but the bottom hose was dead cold and I dont think that the radiator works that well. Any ideas? Thanks!
Feel the radiator, or use a thermometer. Remove the shroud and start testing. I use an infrared one myself, but I don't like burning my fingers on a hot radiator or sticking my hands in the fan. Testing various spots all over, it should be hotter at the top than the bottom, and at a given height, should have a uniform temperature across the face of it. If you see a sudden cold spot where everything above and beside it is hot, you found the problem. If the temperature gradually cools from top to bottom, it is likely doing it's job. Reinstall the shroud and move on to the next potential problem. Given what you say here, it might be the sensor, but you should also start looking at a test of the coolant for the presence of exhaust gasses...
Well I put the new radiator in and still nothing! Waiting on the water pump gasket to get here and we will see if the old motors water pump changes anything considering I can turn the inside unit with my fingers and on the old one I can not.
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