I bought a used 2003 Honda Civic Hybrid with a little under 60K miles on it recently. I took it to a mechanic, ran CARFAX and everything checked out ok. The car drives absolutely beautifully.

I've noticed that sometimes, when I turn the car off, something is still running under the hood--it sounds like a fan. I'd say this only happens about 1 in 4 times I stop the car. If I restart the car, and then turn it off, the noise always stops. I've waited for 10 minutes and it has not shut off by itself. I read the driver's manual cover to cover and it doesn't mention anything about this so I don't have any reference point of how to tell if it's normal or not. I've talked to a couple other owners of the same model and they all have the same experience. One person told me that the noise will turn off after 20 minutes on its own; another person told me it's a fan.

Does anyone know what this is? Does anyone know how I can get some sort of "official" statement about what this is? I want to know what is going on...if it's something I should let run...or if it's something I should continue to turn the car on and off to stop? Or if it's a sign something is wrong? I don't want to just go on word of mouth here.

Thanks!

cazort:

I can't give you any "official" explanation, but my 03' has always done this in the 5.5 years that I've had it.

It's normal. Don't worry about it.

I'm not 100% sure, but I have always assumed the fan is cooling the electric motor after the car stops, and there is no air flow from the moving car, to avoid damage to the motor windings. I would let it run and shut off on its own.

Hope you like the car. I know I've been VERY happy, even though my IMA light is starting to come on at 172K.

One of the best investments I ever made...

Wow...I'd be happy if that or another light didn't start coming on until 172K miles. :-)

Thanks for the response. What kind of miles per gallon are you getting now that your car has seen some heavy use?

I'm still getting pretty much what I always did; right around 50MPG. I've always thought the trip meter avg mpg was a little high, but right now it's reading 52.6MPG after 14,000. (I don't reset it much, like I used too)

Yes, I have been very happy with the vehicle and actually since I started this post the light has stopped coming on. For now.

The weather has cooled a lot since the light first came on, so it's looking like it is heat related. I'll see.

Good luck with yours. I don't baby mine, but I don't really beat it either. Just keep your foot as light as possible and you'll be happy with the mileage.

That's impressive. I haven't been able to get over 50mpg except on certain short trips. My car did not come with the original tires, however...they had been replaced by standard tires.

When you replaced your tires, what did you get?

Thanks. When I first got the car I kind of made a game of keeping that instantaneous mileage slider display on the bottom around 60mpg as much as possible. My best tank was 57.3mpg/703 miles. Of course I literally had to run it out of gas to get that. I did it on purpose, I wanted to see the max so I was carrying a gallon of gas in anticipation.

Slow down. Avoid jackrabbit starts, without overdoing it and being a nuisance to the car behind you. Slow down. Keep it in the highest gear possible while keeping that lower slider display high, it takes a little practice. Did I say slow down yet?

As for the tires, yeah I replaced them with something besides the B381's at about 70K and my mileage dropped. To about 47-48mpg if I recall correctly.

I went back to the Bridgestones on the third set. Mileage went back up, but not as high as when the car was new. I recommend the Bridgestone's but they were up to $93 per tire at tirerack.com last time I checked.

I actually just bought a couple cheapies for the front to get me through the summer, let's see if my mileage drops.

Cheers.

The fan running after you shut off the car is completely normal. Mine does it all the time (desert heat probably makes mine run more than yours). Every small car I've owned has done that, since my 78 VW Rabbit. Many modern cars use electric cooling fans now instead of linking them to the engine anymore. This is one of the reasons they insist that you disconnect the battery before doing any work on the car! That fan can come on unexpectedly at any time.

As for tires, I replaced my OEM Dunlops with Michelin Harmony from Discount Tire. I took a definite hit in MPG, between 5-10%. It's extremely difficult to choose tires for these cars. I could have gotten the Dunlops again, many people hate them but they worked great for me and lasted 50% longer than their warranty to 60k miles. But they were a special order tire and the same price as the Michelins. I really wanted a standard stock tire so I wouldn't get stranded somewhere with a broken freakish irreplaceable tire. I tried to research rolling resistance and such, but there's very little data out there. The Green Seal report everybody totes is so old that hardly any of those tires are available anymore, and consumer reports claims to have rated tires on that criteria but reading their ratings didn't really help much either. If you're getting good mileage and performance out of your tires now, I strongly recommend leaving them on there until you have to replace them. No sense spoiling a good thing, keep it going while you can.