Engine Cooling problem
1995 Honda Civic 4 cyl Front Wheel Drive Manual 246000 miles
I have a 95 civic with 246000 miles on it. It's the EX wit the 1.6 liter SOHC VTEC motor. Around Thanksgiving I changed the head gasket on it because it was leaking. After putting it back together I've been having problems with it running hot. Initially it wanted to overheat all the time and I thought there might be an air bubble in it so I bled it many times and drove it through a few warm up and cool down cycles. The weird part was that when I revved it up the temp would drop but then immediately clime when the engine speed dropped. It still kept wanting to overheat so I tried jamming a bolt in the thermostat to keep it wedged open. It ran cool like this but of course didn't have good heat. Around Christmas time I tried installing a brand new thermostat. This seemed to work a little better but it still didn't run at a consistent temperature. It ran hotter than normal but not too hot. Still the temp would vary with the engine speed as in it would cool down when the engine was revved above about 3000 rpms. A few weeks after the new thermostat I got a check engine light and it would run poorly after leaving cold run mode and before it was completely warmed up. It ran fine when initially started and after being run for at least 15 minutes but in between these stages it would run rough and often stall. The check engine light was for the water temp sensor. There are two sensors in the head near the upper radiator hose one with two wires and one with one wire. I had broken off the one wire sensor when replacing the head gasket and replaced with one from auto-zone that didn't look quite the same so I thought this was the problem. I tired replacing it with one form carquest but it seems to have made no difference. I am now fairly certain that the code is referring to the two wire sensor but don't know if this is related to the engine running hot. Now once it warms up it runs with the temp gauge right at the bottom of the red unless revved at above 3500 rpms. The weird thing is that it never climbs into the red it just stays right there. After a decent drive the radiator feels cold all over even though the temp gauge says the engine was warm. I live in Houghton MI so the outside air temp is cold and I don't know how much the radiator would heat up. The heat works fine but does not feel excessively warm. The upper radiator hose gets hot but not super hot. It seems like either the engine is not getting as hot as the gauge says it is or that there is not enough coolant flowing through. I haven't lost a drop of coolant since the head-gasket change in November. I'm confused as to how the thermostat works being on the bottom side of the engine of this car because it doesn't seem it would get hot there. I would really like to figure this out and am thoroughly confused.
have the same problem?
Friday, March 20th, 2009 AT 11:04 AM