OHSEVENLTZ

I bought an '07 Impala LTZ in October. I noticed right away when driving at night that the instrument panel lights and the headlights would dim down and then go back to normal as I was driving. This happens all the time. Have had the car into the dealer and they have seen the problem, but have now way to fix. GM engineering has said there is no fix at this time. Has anyone else had this problem.

chevy038

I too have a 2007 LTZ and am having the same problem. This is due to the 3.9L shutting down 3 cylinders. When this happens, the belt tension is reduced. To maintain proper belt tension, chevy installed a clutch coupling device on the alternator pulley. Now, the alternator couples/decouples from the drivebelt resulting in varying output, and an increase/decrease in voltage. I was just going to take mine to the dealer to see if they have a fix. On a long trip, however I decided to forgo the cruise control and use my foot to keep it in 3 cyl mode. At higher speeds, 75mph, everything is spinning fast enough that the alternator stays engaged and my lights didnt flicker. Once you go back to v6 mode, this problem doesnt occur. let me know if you have any luck getting this problem fixed!!

indyLTZ

I, too, have an 07LTZ. This problem happens all the time and I was hoping it was not just my car. I am at least glad to see there are others with this problem. I do quite a bit of highway driving in the evening with the lights on, obviously, and it is usually in the three cylinder mode while doing so. Why would the lights constantly flicker? Is the clutch engaging and dis-engaging all the time? It does seem to happen at shift points, so that would make sense. However, the car should have enough power, regardless, to maintain a steady beam with the headlights and the dash lights. I will pay attention to it and see if it happens only in the 3cylinder mode, or if it does it in both modes and get back to everyone. I am taking mine in for its first service this weekend: lube, tighten the bolts, etc..and I will ask them to take a look and see what they think.

art

Just as info, I have a 06 SS with the V-8 that goes to 4 cyl. when all 8 are not needed and have not had the problem you mentioned and have not heard of anybody else with the SS having the problem. I appears there is something wrong with the V-6 to 3 cyl. application. I wonder if there is something in the electronics that when the system goes to 3 cyl. mode there is a parasitic electrical draw on the system causing the dim lights. Could be a short in one of the relays.

SILVERLTZ

I have a 2007 LTZ as well, I have the same problem as described by chevy038.....

Anyone have any updates as what their dealers says in regards to the problem? It truly is a abnormal issue.... You think after making cars for 100 years we would have headlights that wouldn't flicker....

OHSEVENLTZ

I hadn't made a payment on my car when I took it in for this problem. They had it a week and a half and finally seen the problem. The service manager told me that they were told that there was no fix at this time and to give me the car back. Their tac people told the service techs to say that it's normal for this to happen. The service manager drives an 07 LTZ and didn't notice his doing the same thing till he drove mine. Whenever this happens to mine, the compass locks up also. So far on this car I've had to have the tires balanced the day after I picked it up new, trouble with the lights flickering, the day I picked it up after they had it a week and a half for the light problem, I got home and there was a letter informing me that there was a recall on the gas tank. Also, when the weather gets colder, the remote start doesn't work like it should, you have to be on top the car for it to work. They told me that there is to be a recall on the remote start antenna, they should have announced it already, but don't have the parts yet. Now the auto lights won't go out when it's bright outside. They know about the light problem and some of the others. The service manager took me in the back and showed me the web site that the techs go to and there were two messages that morning about the problem. Even the service techs said that the problem wasn't right. The last three out of four cars I bought were new GM products, 1 Oldsmobile, 1 Pontiac Grand Prix, 1 Chevy LTZ and I've had major problems with all three. I have told them at the dealership that I will give them a reasonable amount of time to fix the problems and if not fixed correctly, I am going to get rid of the vehicle and go right to the Nissan dealership. Maybe they can make a vehicle that works right some of the time.

chevy038

I know there is a lot of frustration here, and heck, I am too! I just bought this puppy and this flickering thing is really annoying. But I've been doing my research on this issue, and I've got a master's degree in mechanical engineering and I still got my 2007 LTZ. If i felt it was a bad car, I wouldnt have put my hard earned money on it. The whole issue just started for the 2007 model year, which, is only a couple of monthes old. My 2007 was one of the first ones and I got it in October. This all just started with '07 because of the new active feul management for the 3.9L v6. Last year's 3.9L didnt have this feature, so no alternator clutch issues. currently, the 2007 Impala 3LT and LTZ are the only 2 trims that have this...and the 3.9L only comprises 25% of all Impalas. GM is JUST starting to get a trickle of word on this problem, because there are just so few of this specific cars/models/engines/year on the road just yet. Everyone should talk to GM about this. Going to a dealer, even if they replace the alternator, it's not gonna fix the problem. They need a revised alternator clutch assembly and/or belt tensioner. As far as for now...the clutch deal only works when the engine is in 3 cyl mode, and is below 2000 rpms. Like I said before, when i'm cruising at 75 mph its spinning at 2300 rpm and the clutch is totally locked up and my lights are steady. Also, I found that if I run with my fog lights on too, it seems to improve the situation. Maybe the added electrical load of the fog lights keeps the alternator engaged more. Everyone should post any other info/websites are dealer resposes on this page. Hopefully I can get this fixed, and i too have the remote start antenna prob, then my LTZ will be PERFECT. By the way, the gas tank recall only affected all of 14 cars total...

OHSEVENLTZ

I hadn't made a payment on my car when I took it in for this problem. They had it a week and a half and finally seen the problem. The service manager told me that they were told that there was no fix at this time and to give me the car back. Their tac people told the service techs to say that it's normal for this to happen. The service manager drives an 07 LTZ and didn't notice his doing the same thing till he drove mine. Whenever this happens to mine, the compass locks up also. So far on this car I've had to have the tires balanced the day after I picked it up new, trouble with the lights flickering, the day I picked it up after they had it a week and a half for the light problem, I got home and there was a letter informing me that there was a recall on the gas tank. Also, when the weather gets colder, the remote start doesn't work like it should, you have to be on top the car for it to work. They told me that there is to be a recall on the remote start antenna, they should have announced it already, but don't have the parts yet. Now the auto lights won't go out when it's bright outside. They know about the light problem and some of the others. The service manager took me in the back and showed me the web site that the techs go to and there were two messages that morning about the problem. Even the service techs said that the problem wasn't right. The last three out of four cars I bought were new GM products, 1 Oldsmobile, 1 Pontiac Grand Prix, 1 Chevy LTZ and I've had major problems with all three. I have told them at the dealership that I will give them a reasonable amount of time to fix the problems and if not fixed correctly, I am going to get rid of the vehicle and go right to the Nissan dealership. Maybe they can make a vehicle that works right some of the time.
If you haven't called the GM hotline on this problem, call them. The more complaints the better and they will have to find a fix quicker. My service manager told me to call and complain and that they will call him and he can tell them also.

chevy038

whats the number?

OHSEVENLTZ

The phone number is on page 428 of your owners manual, but here it is also- Chevrolet Customer Assistance Center- 1-800-222-1020. Another phone number for the assistance center that was on my recall notice is 1-800-630-2438. My dealership service department has done everything they can, but they can't fix something they don't know what's causing the problem. I blame GM for this.