01 Honda Civic mystery problems (overheating/running rough)

Hang in with me here. I need to give some background on the issue(s). I’ve taken it to 5 different shops, and have gotten conflicting reports, and no solutions. The car has 170k miles.

The first problem I experienced with this car was overheating while not moving at 40mph or above. When I would stop at a light, or in traffic, the car would get hot. If I was moving at a decent speed, the temperature would come back under control.

The first time I brought it in, NTB couldn’t really see any problem, so they reccommended a coolant flush, thermostat and radiator cap replacement. I did that, and it seemed to deal with the issue for a few weeks. After that, it slowly started acting the same way.

At that point, I brought the car to a Honda dealer, and was told that the head gasket needed to be replaced. Looking for a second opinion, I brought it to a small shop run by a buddy I trust to tell me the truth, and he could not find any problem with the head gasket, and said the symptoms I described (even though he didn’t see them) were inconsistent with a head gasket problem, so he replaced the thermostat again with an OEM part, and again, that dealt with the overheating for a while.

The problem started slowly coming back, and it also started running slightly rough when I would first start it up. After 5 seconds of idling, the car would run smooth. All of a sudden one morning, the car ran so rough at startup that it would not stay running so I had it towed to another NTB. That shop also told me that the head gasket needed to be replaced, so again, I brought it to my buddy, and as soon as he tried to start it, it behaved nomally. It started normally, and it would not overheat, even after hours of operation.

I left the country for a few weeks at that point, and had my Buddy keep an eye on it. He ran more tests, and found an error code indicating that the Electronic Load Detector was faulty. He replaced it, and didn’t have any problems with the car while I was gone. I picked the car up two days ago, and it ran fine, with the exception of again running slightly rough when I would start it, but again it was for only 5 seconds.

This morning, the car would not start. I towed it to a Goodyear, and upon arrival, it started and ran just fine. They don’t see any issues with the head gasket, and are going to keep it overnight to see if they can duplicate the problem tomorrow.

So at this point, I’ve had 5 shops look at it. Two of them replaced the thermostat. Two of them said the head gasket needed to be replaced. Two of them said they don’t see any problem. That seems like fuzzy math, but my Buddy replaced the thermostat even though he didn’t see any problems first-hand.

Any ideas?

NTB and Goodyear are good places to go for batteries and tires. Where does your buddy work?

There are tests to verify a leaking head gasket. There’s no need to guess. Did your buddy do any of these tests? Did anyone?

Overheating at low speeds does not sound like a head gasket problem, but the overheating seems to have been solved.

When you say “the car would not start,” what does that mean? What, exactly, happens when you turn the key?

Thanks for your response.

He has his own shop. He ran a “Combustion Leak Test”, which it passed. So either I’m being lied to by someone, or the test results are changing.

The overheating is not solved. The problem with overheating was coming back when the problem with running rough started. What I mean is, after the thermostat was replaced, the car was fine for a short period of time. After a few weeks, I would notice that the temp would get a little higher that usual, but would come back to normal. Eventually, it would completely overheat if I didn’t prevent it by turning off the engine.

This morning, when I tried to start the car, it would turn over, and the pistons would fire intermittently, but would do so so eratically and rough that it would not stay running. It would basically cough and sputter so badly that it could not stay running.

The overheating symptoms you described don’t match a leaking head gasket, and since the car has been leak tested I’m going to assume the head gasket is not leaking.

If your buddy has his own shop and you trust him, why are you going to NTB and Goodyear?

When the engine overheats, does it boil over and push coolant out of the radiator, or are you just watching the temperature gauge climb? Has anyone measured the actual temperature of the coolant?

Has the fuel filter been changed lately? How’s the fuel pressure? If you turn the key to “ON,” wait five seconds, then turn it to “START,” does the engine start or run any better?

Does the CEL ever come on?

If the car passed a “HC in coolant test” that is one thing, but…

If a leaking head gasket allows coolant to trickle into one or more cylinders when the engine is stopped, the engine will run rough when first started.

My car is an '04 Civic EX (same generation). Before starting the car after sitting overnight (cold engine-max trickle time) remove the radiator cap. You should be able to add just a very small amount of coolant, maybe 2-3 tablespoons max. If you can add more, there is a leak somewhere, and with the other symptoms, a head hasket leak rises to the top of the list of suspects.

While the hood is open, check the coolant level in the reservoir.

Can a 3rd person observe (sniff) the exhaust when the first start is attempted? The coolant smell will carry thru the cold cat and there may be a white mist for a short time when the engine first runs.

One last question, is the oil clear? Milky oil is another sign of a leaky head gasket.

Can you think of any reason why the repairs that were performed “seemed” to fix the problem?

What is a “electronic load detector” and what does it do? When it fails what are the symptons? is one of them overheating?

Tell them to lok into your temp controls…whatever they call them…coolant temp sensor…coolant relay sensor…it’s amazint the trouble these little components can cause. I’ve got a GM…but what you describe is what I’ve been dealing with over a year.

The overheating sounds like the fan isn’t always running when it should, but I have trouble believing that 5 shops would fail to notice that. So let’s set that aside for the time being. Keep in mind that a balky fan or a defect in the stuff that is supposed to turn it on could cause the overheating, but not the hesitation on starting. Other things could cause a cylinder not to fire for a few seconds when the car is first started.

The hesitation on starting does sound like a head gasket leaking coolant into a cylinder. Let’s assume that for some reason, the normal pressure test isn’t detecting the leak but it is there. Why not get your buddy to pull and examine your spark plugs? If coolant has been leaking into a cylinder, the cylinder that has been leaking will probably have a shiny clean plug whereas the other plugs will be somewhat discolored by combustion products. If, on the other hand, a cylinder hasn’t been firing on start up, its plug probably have carbon deposits that other plugs won’t. Your buddy can take things from there.

I’m having the exact same problem with my '99 Civic DX. I only took it to one shop so far, and I’ve tried flushing the cooling system many times and changed the thermostat. My car is overheating intermittently even at high speeds, and when it does, I don’t get heat in the cabin. The gauge goes up almost to the red, and then suddenly drops to normal, and at the same time I start to get heat in the cabin.
The rough starting is also a relatively new development for me. It seems to happen only when the car is cold, and only for about 5 seconds every time…after that, it runs perfectly. Did you ever figure out what the problem was?

If it is only overheating under 40, your fan is not running when it should or the water pump is going bad, Worn out impellers or whatever drives it is slipping. You may not have had a bad head gasket,but any overheating could cause one, also some head gaskets leak only when hot and under load. A chemical test of the coolant for exhaust residue will show those. Fan controls can fail in an erratic fashion.

I’m pretty sure the rad fan is not an issue here, because the overheating continues even at highway speeds, and the key thing is that there is no heat coming in the cabin. This tells me that hot water is not circulating to the heater core. Again, I tried flushing the block, heater core, and radiator separately, with no sign of any obstruction or clogging. Keep in mind, the whole overheating issue happens only once in a while: maybe once or twice a week after a cold start.
The rough starting issue is happening consistently on cold starts. Sometimes I have to start it 3 or 4 times before it stays running. It sounds like the car is running on 2 or 3 cylinders for about the first 5 or 10 seconds, and then it suddenly starts running smoothly, and continues to run perfectly smoothly until the next cold start. I did a compression test today after warming up the car, and all of the cylinders show pressures of about 140.
Anybody have any suggestions on what else I can try? I’m thinking maybe a sensor somewhere is malfunctioning, but I don’t know where to start. I’m worried that come winter, I will have even more trouble starting the car on frigid mornings.

I have experienced similar issues (minus the rough running) with my 01 Civic for the past several years. Did you ever resolve your problems?

IT’S THE FAN!!! I went through close to 2 grand tracing the overheating problem in my '04 Civic. Several new thermos, a new radiator, a head gasket job, and the thing still overheated!!! My return trip to the dealership, where the head gasket was replaced, and guess what: the fan contacts were crappy and just needed a cleaning and everything was ok. I recommend that we Civic owners band together and start a class action suit, 'cause Honda had to know about this issue for years, issued no recall or repair alert, just so they could string us along for max bucks and then clean the fan contacts. Occupy Wall Street!!!