Mechanics

THERMOSTAT CHANGE?

1995 Honda Civic

Engine Cooling problem
1995 Honda Civic 4 cyl Two Wheel Drive Manual 206000 miles

After starting my car on a very cold morning, it started idling erratically while warming up. I started driving and noticed that I wasn't getting any heat at all from the blower. After about 5 miles the car started to overheat. I immediately pulled over and let the engine cool down. I've checked the oil for coolant mixture but it still looks fine. I can still drive the car for short distances (still idles erratically) without overheating. If I change the thermostat, will this fix the problem or is there something else I need to worry about?
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Jfuzz521
February 9, 2009.




You need to test the thermostat first.

With the vehicle at operating temperature both rad hoses should be around the same temperature. If the lower one is significantly cooler than the top hose that will indicate that the thermostat is stuck closed when it should be open.

F4I_guy
Feb 10, 2009.
F41-guy,

Thanks for your response. The temps were significantly different. I changed the thermostat today and topped off the coolant level. After driving for a while the temp gauge fluctuates between the 2 and 3 o'clock position. Also, I still don't get any heat from the blower. Just cool to warm air in all positions and levels. Any thoughts?
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Tiny
Jfuzz521
Feb 10, 2009.
It sounds like you did not bleed the coolant system properly.

With the engine cool, remove the rad cap and top up the coolant. Leave the cap off and start the vehicle with the heat on full. Let the vehicle idle until the thermostat opens up (so until both hoses are the same temperature) and you get heat coming out of the vents. Once this happens, usually all the coolant is bled out of the system.

Keep in mind as the vehicle is running the coolant level will get lower and lower since the air pockets are escaping, keep on refilling the radiator to the top.

F4I_guy
Feb 10, 2009.

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