Hey! We have a 2002 Civic LX with 98,000+ miles. My boyfriend got it in March and around June it started to overheat. My boyfriend drove it to work everyday, about a 30 min drive, and when he was getting close to his job it would start to overheat. When we used the a/c it would heat up even faster.

I would use the car to drive into downtown to the hospital area, about a 30 min drive, and it never overheated for me. But in the past 2 months, we were only able to drive the car for about 20 minutes, without the A/C and 10 or less with the A/C. Now, it can barely drive 10 min without the A/C.

My boyfriend put the fan directly to the battery so when we need to drive a high distance we connect the fan so it won't over heat as fast. It lasts longer like this but it will eventually do the same thing. The transmission light will turn on, and then if i have to make a stop, the engine will turn off. I have to put the car in park, turn the key to off, wait a few seconds and then turn it on again. And when on, it'll runs at no more than 5mph. I have to let it sit, open the hood and let it cool off for about 30 min. (You have no idea how hard it is to push this car in heels all alone!)

We've taken it to many mechanics and they all say the same thing- "It's the catalyzer"...

The Catalyzer is NEW
Oxygen sensors are NEW
the fuse for the fan is NEW (cause it wasn't working so it wouldn't automatically turn on)
the thermometer is fine
AND IT STILL DOES THE SAME THING!!


A friend told me it may be a package in the motor that eats away when the car is ran up to red on the thermometer. Anyone know anything about this??

Any suggestions, ideas or advice will be greatly appreciated. Even if you know a mechanic here in Houston that can help, we're open to suggestions. Thanks!

 

coolant level? ever have to top it off? i'm willing to bet it's a headgasket issue, very common for these cars. i either put a funnel on the rad cap, let the car idle and watch for constant bubbles coming up, or i perform a cylinder leak down test with a funnel on the rad cap. did you try bringing it to the dealer? and if the problem is still there i would ask to be refunded for the repairs performed unnecessarily. i.e. the cat.

 

If by catalyzer you mean catylitic converter, that's probably not the cause. Oxygen sensors probably aren't a cause either.

The cooling system is very simple; there are only 4 main components:
1. Fan/radiator assembly
2. Thermostat
3. Waterpump
4. Fan switch

The coolant is pumped throughout the system by the waterpump which is mechanically driven by the timing belt. The coolant only flows when the thermostat opens at a specific temperature. Once the coolant reaches a certain temperature and the thermostat opens it is pumped out the radiator and cooled off while the already cooled coolant that was in the radiator sits in the motor. The fan is only useful when sitting still; the car should have no problem keeping cool when on the highway because there is a constant stream of air hitting the radiator. The fan only turns on when the thermostat opens and the heated coolant hits the fan switch triggering the fan. If you're overheating while doing 65mph you're most likely low on coolant. You just need to find out where it went.


1. Check the coolant level and top off if low. Take note if the coolant has oil in it or is discolored black.
2. Let the car idle with the radiator cap off. It's very easy to get an air bubble in the coolant system; doing this will let any air out.
3. Do a compression test, assuming the car doesn't eat oil if one cylinder has low compression that will be a good sign of a bad headgasket.
4. Do a leakdown test on that cylinder.

A bad headgasket does not cause overheating; the lack of coolant because it's been combusted due to a leaking headgasket causes overheating.

 

I will try these things because I think the coolant is fine and the water pump works properly and we do believe the thermostat is fine. and yes! Catalic converter... Sorry, I try my best to translate between spanish and english and vise versa

 

With the motor cool check the coolant in the overflow and the radiator. If both are fine I would lean towards the thermostat.

You said the thermometer was replaced, I assume you mean thermostat? Was it an OEM thermostat from the dealer or an aftermarket part from a parts store? There have been MANY MANY people that have had problems with aftermarket thermostats in 7th gens. If it's aftermarket I'd get it replaced with an OEM thermostat.

If the coolant is low and the car continues to loose coolant and there is no leak it's prob a bad head gasket.

 

This happened to me while on a road trip. I went through a hole bottle of coolant before pulling over on the highway and pulling out my thermostat. I ended up making it another sketchy 500kms home when I finally decided to swap in my new motor. I only went this route because I bought the new motor a few yrs ago

 

A few things, it overheats after driving 30 mins or so, driving and idleing right?

Ever do the timing belt yet? If not you should plus they do the water pump at the same time, sometimes the water pump goes bad and will not circulate the coolant.

As other said a cheap fix to try is the thermostat.

You can also pressure test the system to check for leaks, never know a small leak can creep up on you.

 

I will try all these things, once I figure out how to say them in spanish to my boyfriend lol

We want a quick fix because he has someone who wants to buy the car cash but as long as it doesn't overheat anymore. Thanks for the input, I will comeback and tell you what happened!

Oh and i don't think we changed the thermostat, if i said that, sorry. But the only thing I know of that was changed to new was the catalictic converter, the oxygen sensors and the fuses. and the water pump is working fine.

And yes! sometimes we forget to disconnect the fan since its direct to the battery and when our battery dies we have to keep it running for a while after recharging to keep it charged and we leave it idle sometimes and it overheats in about 20 min.

 

take a peek at the overflow hose. It should be directly to the right of the radiator cap. A lot of times when the headgasket blows and excessive pressure builds up the hose pops off. Now, as the coolant expands, instead of being pumped into the overflow tank, it is ejected into the engine bay, obviously with no way of getting it back into the coolant system. I had that hose constantly popping off and we found the head gasket to be the problem. As a note, you should not have a clamp on this hose, as no pressure should be building up in that hose

 

It was the camshaft sensor

 

^how does that cause overheating?

 

i was told the sensor regulates the amount of gasoline that is passed through the car and when it stopped working the gasoline got stuck and caused the catalizer to over heat because most of the time we had to keep driving the car for somewhat of a time to get to a parking lot.