Before any one begins to complain, I have searched far and wide and have come up with nothing.


I have a 94 Civic VX with the stock VTEC-E engine. The car was running fine for a while when I first bought it with the exception of disapearing coolent, although there was never a puddle under the car. I finally found out that the head gasket was shot so I went ahead and changed that for a brand new one. That fixed the disapearing coolent but now my car began to overheat. I went ahead and changed the water pump thinking that would solve the problem, no luck. I then changed the thermostat and the radiator cap and it still overheats. The fan turns on but I can't tell whether or not it is turning on at the correct time. The temp gauge fluxuates between normal temperture and almost RED whenever it pleases, doesn't matter whether I'm on the freeway or the city driving.

Any help would be great, I can't afford to keep buying random parts assuming I will eventually fix this problem. Thanks for the help.

 

You've mentioned you searched and such, and have done a head gasket swap which definitely shows commitment and know-how. I'm just curious if the cooling system was fully bled when re-filling radiator and such. Does it go near the red even while on the freeway? Happen more while idling?

 

It has been over heating while heavy acceleration and 70 to 80mph freeway driving. Randomly overheating at red lights as well. Thats why it has been so dificult to fix.

 

how is the condition of the radiator.?

 

The radiator doesn't seem to be leaking fluid and the small fins within it seem to be well. But I wouldn't know whether it might be clogged or not. Are there any ways to tell if it is cooling sufficiently?

 

what about the temperature sending unit

 

open your radiator, is it full of fluid? if not, then top it off then your problem should be fixed. It fluctuates because your fan is turning on when it overheats, so there has to be some fluid in there.

 

buddy of mine had the same exact problem. Check your CTS.

 

just wondering, whats a cts???

 

im guessing Coolant Tempature Sensor

 

yup. Coolant Temp. Sensor.

 

Ok I'll check it out. Any other ideas?

 

I havn't gotten around to checking the coolent temp switch but I decided to take out the thermostat for a day and see how it would react to that. I drove it on the freeway and the needle still reaches 3/4 of the way up on the gauge. On the street, when I come to a complete stop at a red light, the car will also begin to heat up to about 3/4 of the way up and then I hear the fan turn on. The car then begins to cool down to its normal operating temperature.

If the car is heating up on the freeway at about 70mph without the thermostat in it wouldn't that indicate that the radiator is not cooling the coolent well enough????

 

I'm having the same problem. Changing the hg this weekend, but my motor's got to the point where you can hear it boiling/bubbling in the resevior tank while in the car.

 

My car never got that bad, now I'm wondering whether or not it was ever overheating.

 

check the fan relay?

 

Fan relay seems fine, the fan turns on and off. But should the fan turn on after the car was being used once I turn the car off?

 

it depends how hot your motor is at that time. Did you check your coolant temp sensor yet?

 

If itls the one that controls the temprature needle on the dash then yes, that was the first thing I replaced.

 

no not the sending unit. Check the one that goes to the ecu. From the way your describing, that's how my buddies car was running. Then we replaced the sensor and that solved
It.

 

Is that the one thats screws directly into the engine block, right underneath the top radiator hose? Doesn't that one control idle rpm?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rad_Teg &raquo;</TD></TR><TR><TD CLASS="quote">Is that the one thats screws directly into the engine block, right underneath the top radiator hose? Doesn't that one control idle rpm?</TD></TR></TABLE>

I assume the sensor we are talking about replacing is the thermoswitch which is located on the thermostat housing. very simple to replace. its aggravating trying to understand which sensors people refer to because they use so many different names sometimes.

my car has this unusal idle problem as well and has been this way since i got the car over a year ago. i've bled the coolent, changed the rad cap, checked the fan relay, fan does kick on but late, and some more things that right now i can't think of.. but i just recently purchased a new thermoswitch and i plan on putting it in soon so i'll be back with my results.

 

does the temp gauge go up and down uncontrollably? like its going crazy??

 

try bleeding i had same symptoms, jus had air in system

 

yo bud, seems to me like you already done everything except one thing. just change out that old radiator. buy one off ebay. cheap and it should be okay.

http://cgi.ebay.com/92-99-00-H...0.m14

theres the link to one on ebay. why not get rid of the old one and come back stronger. you already went through all the trouble of changing the head gasket n all. this would do the trick. I'd garantee it.

oh and you can check you old radiator if it still flows water. it'll require you to remove the radiator and just stick a water whose in the top and see how much what flows out the bottom.