(SORRY ABOUT THE INCOMING ESSAY, JUST WANT TO MAKE SURE I'M NOT FORGETTING ANYTHING IMPORTANT)

Hey all, so I have a 2003 Civic EX sedan with 66,000 miles that's had zero problems until yesterday.

After driving through stop-and-go street traffic for over half an hour, I pulled up and waited at a drive-thru. After a couple minutes I realized steam was coming from under the hood and the temperature gauge was passed the maximum line. I pulled over and heard a bubbling/sizzling noise from under the hood, sounded like the coolant. I also saw some coolant leaking underneath. After a couple minutes I popped open the hood but didn't notice anything out of the ordinary. I slowly limped the 1/4-mile home but the engine had cooled and remained around the temperature midpoint.

Today I drove normally for 1/4 mile to a mechanics shop. There was no issue on the way there. The guy checked some stuff out for ten minutes. He confirmed that the coolant level was normal (I had already checked). He put the car in Park and pushed the accelerator down for a couple minutes but the temperature remained normal. He also said the fan came on normally (I hadn't checked). He pretty much shrugged and said he couldn't tell what the problem was, but thought it MIGHT be a bad thermostat or a faulty fan switch. He told me to make sure the temperature didn't go past 1/2 and bring it in for those repairs (I think he said it would cost $200ish) if it happened again.

Lo and behold, as soon as I pulled away after five minutes I noticed the temperature was rising. I realized it would get to 2/3 and even higher at the red light, but would drop to around 1/2 when I started moving. The gauge would go up and down pretty rapidly in front of me as I stopped and accelerated. By the time I parked, it was almost at the max temperature line again.

So I'm guessing it could be a faulty fan switch, but that doesn't explain why the mechanic told me the fan turned on normally while he was revving and testing. Also, based on what I've read on forums, the worst-case (and most expensive) scenario is a blown head gasket.

My trusted and reliable mechanic that I used to go to (before I moved to LA) is about 45 miles away, and I don't think I should risk the drive so I'll have to take a chance with a local mechanic off of Yelp.

I also am short on both time and money, so I want to try and get it right the first time tomorrow or Friday.

So based on the symptoms, and the fact that the car only has 66k miles on it, which repair should I look at first, with the best chance of getting it right quickly and cheaply? (Fan, thermostat, radiator, coolant system, head gasket, etc).

Also, some more info:
- About 2 years ago, I hit some debris on the freeway and got a very tiny dent on the front of the radiator behind the fog lights/grille. But never any problems til now.
- No engine warning lights on.

Thanks guys!


Also posted in:
<http://www.clubcivic.com/board/showthread.php?t=223817>
<http://www.civicforums.com/forums/36-mechanical-problems-vehicle-issues-fix-forum/357268-idling-overheating-problem-came-out-nowhere-afraid-its-head-gasket.html>

 

You need to check if the fans are running when they should be.

Turning on the air conditioner will force the fans on. Conventional advice is to turn off the air conditioner when a car starts to overheat, but if the overheating is because the coolant temperature switch didn't turn the fans on, forcing them on through the air conditioner will actually help.

 

K. Gonna have fan switch and thermostat replaced today, plus coolant drained and replaced. Hopefully that works...