Ok, so... my car has a lot of symptoms and I'm not sure if they're all related or not. Here goes:
1. First of all, when started cold and for the first 10-15 minutes that the car is running, the revs will jump and drop and the lights (both headlights and the dash lights) will dim and brighten. When the revs jump the lights dim, and when the revs drop the lights brighten. As you can imagine, this is quite annoying when driving at night. It also creates a noticeable loss of power when the revs drop/lights brighten.
2. Sometimes, when the revs drop and the lights brighten, the temperature gauge will climb even though the car is clearly not overheating. As soon as the revs jump back up and the lights dim, the gauge drops (instantly) back to normal.
3. When the lights brighten/revs drop, the radio will sometimes cut out with a sudden pop, and then come back in when the lights dim/revs jump.
4. At idle and low speeds, there is a noticeable growling sort of noise coming from the engine/exhaust, particularly while the engine is in its lights bright/revs low part of the cycle.
5. Over the last six months I've had two batteries die, including a brand new one I got to replace the first one that died. Both followed the same pattern--slowly losing oomph when starting the car until they were just dead. I've also replaced two distributors over the last two years.
As I've said, the majority of these issues disappear after the car has been running for 10-15 minutes. It seems clear that there's some kind of voltage regulation issue going on. I've been told it might be a hard-to-track-down grounding issue, or it might be the ECM/ECU, or it might be a bad alternator (though the alternator, when I had it tested about three months ago, checked out ok).
Anyone got an opinion?
1. First of all, when started cold and for the first 10-15 minutes that the car is running, the revs will jump and drop and the lights (both headlights and the dash lights) will dim and brighten. When the revs jump the lights dim, and when the revs drop the lights brighten. As you can imagine, this is quite annoying when driving at night. It also creates a noticeable loss of power when the revs drop/lights brighten.
2. Sometimes, when the revs drop and the lights brighten, the temperature gauge will climb even though the car is clearly not overheating. As soon as the revs jump back up and the lights dim, the gauge drops (instantly) back to normal.
3. When the lights brighten/revs drop, the radio will sometimes cut out with a sudden pop, and then come back in when the lights dim/revs jump.
4. At idle and low speeds, there is a noticeable growling sort of noise coming from the engine/exhaust, particularly while the engine is in its lights bright/revs low part of the cycle.
5. Over the last six months I've had two batteries die, including a brand new one I got to replace the first one that died. Both followed the same pattern--slowly losing oomph when starting the car until they were just dead. I've also replaced two distributors over the last two years.
As I've said, the majority of these issues disappear after the car has been running for 10-15 minutes. It seems clear that there's some kind of voltage regulation issue going on. I've been told it might be a hard-to-track-down grounding issue, or it might be the ECM/ECU, or it might be a bad alternator (though the alternator, when I had it tested about three months ago, checked out ok).
Anyone got an opinion?