My 04 Civic EX started overheating last winter & continues to do so frequently. It is most common in traffic when it's stop & go conditions. In the past, I would blast my AC on high & it seemed to fix the problem, but lately it's been continuing despite my AC blasting efforts. I've checked the radiator fluid (filled to the brim), replaced the fan relay & radiator fan switch, but the problem persists. I took it to an Auto Repair Shop today & was quoted $215ish for the thermostat to be replaced & radiator to be flushed. My question is: is that a reasonable price to pay? And do I have to have the radiator flushed when changing the thermostat, like I was told? For reference: car is a 1.7 liter SOHC 16 valve VTEC 4 cylinder engine. Thanks for the help!

 

Overheating ONLY when the car is stopped is almost always because the radiator fans don't work. Turning the A/C on forces them to come on. There is also a switch (at the bottom of the radiator I think) that turns them on when the radiator gets too hot. When the switch is bad then you had to turn the A/C on. The problem now could be that the motors are worn out or the fuse is blown.

Bad thermostat or clogged radiator tends to be worse when the car is on the highway instead of idling.

 

Thank you for the reply- I'll see that those are checked. Thanks!

 

Replecement thermostat is about $15-20, and is easily accessible for you to change yourself. Radiator flush is not necessary when replacing t-stat, but after 10 years you might want to consider a flush and coolant replacement. Again, its easy to do yourself. Radiator shop would probably do it for $50.