Mechanics

ENGINE OVERHEATING

1997 Honda Accord

Engine Cooling problem
1997 Honda Accord 4 cyl Wheel Drive Type unknown Automatic 65000 miles

Recently, my honda accord 1997 VTEC model with automatic transmission had an overheating problem. When I was driving, I noticed that the temperature is rising and going to the red zone. So I stopped and opened the hood while the engine is still running. I noticed that the radiator fan is not running even when the engine is so hot at that time. I turned the AC on and both the AC fan and radiator fan turned on. But making the fans turn on at that time could no longer lower down the temperature which was already above the middle mark of the gauge. Turning the AC off also turned both fans off. So I shut off the engine to let it cool down. When it was cooled down, I opened the radiator cap and found the level of coolant ok, so I discounted any possible leaks. I called a friend and was advised to check for the thermostat. But I dont know where the thermostat is located. Is it the one connected to the upper radiator hose or the one connected to the lower radiator hose at the engine side? I also noticed that the upper radiator hose is too hot while the lower radiator hose is not hot or is just warm maybe. Is it possible that the water is not circulating? What could be the problem why the fan is not automatically turning on when the engine is hot? Please advise. Thanks.
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Goldentrail
March 20, 2008.



Mounted on the thermostat housing, wich is at the end of the upper radiator hose, find the fan switch, test it and the relay in the underhood fuse box. If the fans work when a/c comes on it will most likley be the switch on tstat housing!

Merlin2021
Mar 20, 2008.
I tested the switch located in the upper radiator hose and shorted the terminals using a paper clip, but the fan didnt work. but when i detached and shorted the switch located at the lower radiator hose which is at the engine side, both the fans (AC and radiator fans) turned on. So what is that switch that made both the AC and radiator fans turn on? I am really confused if which is really the thermostat housing, is it the one on the lower radiator hose or the one on the upper radiator hose? I would also like to know how to test if the water/coolant in the cooling system is circulating or not. This is because i noticed that the upper radiator hose is too hot while the lower radiator hose is cold, so i presumed that the water is not circulating in the system. Inserted a picture here showing the connections. The lower portion of the picture with the green switch is the upper radiator hose connection, while the upper portion of the picture with another green switch is the lower radiator hose connection to the engine. Thanks.


http://www.2carpros.com/forum/automotive_pictures/170607_055_1.jpg


Tiny
Goldentrail
Mar 20, 2008.
My mistake the one on the lower hose has the thermostat! In your case you may have a stuck thermostat, that will be the firest thing to change. If the water is cold at that lower hose, the switch will not turn on the fans! Flush and fill the cooling system while your at it. If after replacing the tstat, the fans don't work, replace the switch.

Merlin2021
Mar 21, 2008.
Thank you. I will try that. My problem now is how to remove the thermostat housing considering the many wirings and the big hose that are blocking it. Thanks again.

Tiny
Goldentrail
Mar 21, 2008.