I've got a 2001 ZX3. I bought it used with 55K miles on it. It now has 167K.
About a month ago, I saw a Check Engine light one morning. It was running fine, and I didn't have time to look into it, but eventually (a few days later) the light went out. A week later, the car started one morning but ran rough, like a cylinder was misfiring. This was especially apparent at low speeds. Once on the highway, it was fine. The Check Engine light came back.
At first, I started with something simple - the spark plugs. I had never replaced them since I owned the car. I put in new plugs, properly gapped, and new plug wires. It was during this process that I discovered a leaky valve cover gasket. New plugs did not improve the situation. I took the car to my mechanic for a new gasket, and telling him about the misfiring, we decided it was fuel system related. He suggested starting simple (and cheap) with a new fuel filter. I figured it needed one anyway.
No improvement. At this point the car's been running like a dog for a few weeks. I decided computer diagnostics were the next step. My mechanic wasn't able to get me in soon enough, so I took it to another that I've dealt with.
This mechanic reported that the misfire was happening on random cylinders, not just one. He also reported some alternator codes, but was not convinced they were to be believed. He cleared the codes and reset the computer. He claimed the car ran as new after this.
I went to pick up the car yesterday, and it wouldn't start. It cranked a few times, VERY slowly, and basically behaved as if the battery were going dead. He jumped it and it ran well enough to get it home, but with the same symptoms as before.
When I spoke to him, he revealed that when he was test driving it, the instrument cluster went haywire on him at one point.
He's convinced it's NOT the alternator, but rather a possible computer problem. He also suggested a problem with the wiring, saying that there are up to 50 ground points in the system and any one of them could be bad.
I've suspected a bad alternator for some time, owing to the horrible noise my AM radio makes, especially when braking or using the turn signals. (In my past experiences with other vehicles, an excessively noisy AM radio means the alternator is dumping RF junk into the system, usually a sign that it's dying.) But then, this car has had that symptom for a couple years.
I'm not sure how old the battery is, but I've never replaced it.
Apologies for the lengthy post, especially for a first timer.
Any thoughts?
About a month ago, I saw a Check Engine light one morning. It was running fine, and I didn't have time to look into it, but eventually (a few days later) the light went out. A week later, the car started one morning but ran rough, like a cylinder was misfiring. This was especially apparent at low speeds. Once on the highway, it was fine. The Check Engine light came back.
At first, I started with something simple - the spark plugs. I had never replaced them since I owned the car. I put in new plugs, properly gapped, and new plug wires. It was during this process that I discovered a leaky valve cover gasket. New plugs did not improve the situation. I took the car to my mechanic for a new gasket, and telling him about the misfiring, we decided it was fuel system related. He suggested starting simple (and cheap) with a new fuel filter. I figured it needed one anyway.
No improvement. At this point the car's been running like a dog for a few weeks. I decided computer diagnostics were the next step. My mechanic wasn't able to get me in soon enough, so I took it to another that I've dealt with.
This mechanic reported that the misfire was happening on random cylinders, not just one. He also reported some alternator codes, but was not convinced they were to be believed. He cleared the codes and reset the computer. He claimed the car ran as new after this.
I went to pick up the car yesterday, and it wouldn't start. It cranked a few times, VERY slowly, and basically behaved as if the battery were going dead. He jumped it and it ran well enough to get it home, but with the same symptoms as before.
When I spoke to him, he revealed that when he was test driving it, the instrument cluster went haywire on him at one point.
He's convinced it's NOT the alternator, but rather a possible computer problem. He also suggested a problem with the wiring, saying that there are up to 50 ground points in the system and any one of them could be bad.
I've suspected a bad alternator for some time, owing to the horrible noise my AM radio makes, especially when braking or using the turn signals. (In my past experiences with other vehicles, an excessively noisy AM radio means the alternator is dumping RF junk into the system, usually a sign that it's dying.) But then, this car has had that symptom for a couple years.
I'm not sure how old the battery is, but I've never replaced it.
Apologies for the lengthy post, especially for a first timer.
Any thoughts?
