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Pontiac Grand Prix Rattles, Clunks and other odd Noises



  • rmozolrmozol Posts: 124
    My hissing only lasts about 15 seconds or so. I think that it's tied into the courtesy light circuit or something. You now, the power stays on for a short while after you get in or out? When I get time, I'm going to mess with the timer duration and see if that changes anything.
  • chats1chats1 Posts: 158
    I have a 2006 GXP since last August with 10,600 miles on it. I am sending one message re all three topics being discussed. First, my sunroof seems just fine when it is open -- same as my other three GTP's with the sunroof. I haven't noticed any significant noise at all. Second, I have the hissing/humming noise too -- I'm probably the bigest complainer of this -- now I just ignore it. Anyway, it stays on about 15 seconds, goes off, does not interfere with my radio or cd's. Don't even waste your time calling Customer Assistance Center because they are not knowledgeable about the car; they only look up what you ask them in the manual and call the dealer. They told me that. They are useless. They know nothing about this car. They just want to get rid of problems; not solve them. So, don't waste your time. You will just get more aggravated. I have called them many times -- it was just a waste of my time and very frustrating. I even told them at one point "What good are you? I can certainly read a manual and call the dealer." I still think it is related to OnStar since OnStar is now digital in the new cars, not analog, as before, and the speaker probably has not shut off. OnStar monitors the car all the time and has a speaker. Do you think GM will admit this. Of course not. That's why they say "there is no remedy at this time, it is not harmful." What would they do, tear out the OnStar System. I doubt that and who would want that anyway. Third, I have no problem whatsoever when I use my automatic climate control -- ac or heat. It works as it should. I am very very happy with my car. It took me a while to get used to it. It's my first 8 cylinder. My other 3 GTP's were all supercharged and I thought they were fast. Now, I'm spoiled. I couldn't drive anything with less power!!! The car was worth the money.
  • dblducedblduce Posts: 58
    I own a 2005 GXP and interestingly, i have never heard the "hissing" sound some of you speak of. My model didnt come w/ the OnStar system, and im wondering if that could be the culprit. It would be interesting to see how many people have that problem, and also have Onstar installed. I do have the XM radio, but i only used it for the first 3 months when it was free, and didnt purchase the plan, hence i dont use it. Im just glad i dont have the hissing noise as described, because i am very particular also about little annoyances like that, and it would drive me crazy until i had found a solution to it.
  • chats1chats1 Posts: 158
    Are you sure that you don't have OnStar. I thought it came standard on all GXP's. I also had OnStar on my 2002 GTP which came standard and I had the Bose system but on that model OnStar was analog, now OnStar on the new cars is digital. My brother is an electrical engineer and insists that it is OnStar causing this problem. I did subscribe to XM because I figured if I bought the radio which, of course, was in one of the packages, I might as well get the plan so I subscribed for one year. I enjoy it, but also listen to my other AM/FM stations as well and my CD's.
  • ps: onstar is standard on all GXPs. (As is the stability control, Heads Up Display and big monster brakes and...)....
  • Hissing? None here whatsoever. I don't have a the monsoon radio upgrade. I stuck with stock and upgraded the speakers instead.

    My car is very quiet. No sunroof!

    I don't drive mine much. My wife always has it. The car is a complete joy to drive. Kids love the back seats, surprisingly. My wife is no racer, but she loves the incredible POW of power that happens when you touch the gas. She commutes through heavier traffic and if some dork won't let her merge she just zooms ahead of him in 0.25 seconds. Brakes are also awesome.

    Don't see many of these cars around, which is a bit odd. Everyone who drives ours scratches their chins and asks, "So how much did you pay for this?" When I tell 'em they kinda hint they may have to take one for a test drive.
  • sahoward1sahoward1 Posts: 19
    I agree the hissing is freaky, but it goes away in a few seconds. The AC comes on every time you start the car, which is nonsense nine months out of the year in New England. CAC is totally useless. They wasted a month of my time. My dealer and CAC say this is normal operation to help defog the windshield. Duh! If's it dry out, why do I need to defog my windshield? The AC should default to where the driver left it, and there does not seem to be a fix or reprogram for this problem. I should not have to press that snowflake every time I start my car. Neither should I have to drive around wasting gas with my AC on. This happens in manual as well as automatic climate control. And it happens in every mode. I'm thinking of installing a kill switch. Do you think that would void my warranty?
  • bob97bob97 Posts: 16
    With the auto-dual climate system, if you leave the vent control set to off, the AC and fan do not come on when you start the car.
  • chats1chats1 Posts: 158
    Exactly, so that is why we have no problem. when I'm not using my ac or heat I turn it off. when I want it on, I turn it on. The salesperson did tell me when I purchased the car to always leave it on. I had no idea why he said that, but I turn it off when I don't need it. Why leave it on. I do exactly what I did with my other GTP's. Chats1
  • chats1chats1 Posts: 158
    when I am not using my ac, I turn it off. When I want it on, I turn it on. I always use automatic climate control, but turn it off when I don't need it even though the salesman told me to always leave it on. I don't know if the remote starter has anything to do with any of this because even though I have the remote starter with my car I have no need to use it. My car is always parked inside -- in my garage, at work, at the mall, etc. I don't understand what this ac problem is. As far as a killer switch, I would be afraid of installing anything myself in this car because if you mess something up, your warranty would be void, unless the dealer does you a favor and just puts it under warranty. I have been going to the same dealer since 1992 and have bought five Pontiacs from them, so they know me very well and I never have any problems with them and I trust them. when I have a problem or think I have a problem, I go to the dealer.
  • sahoward1sahoward1 Posts: 19
    I know if you shut off the entire heat/AC system, it doesn't come on. But... then when you turn on the heat, the frigging snowflake light comes on. I used to leave my GTP set to where I wanted it, and it always defaulted to where I left it. This stupid system defaults to AC if the outdoor temp is greater than 40 degrees F. CAC and the dealer say that's to help defog the windshield. If it's dry and 41 degrees, I need heat not AC. My old dealer, where I bought four Pontiacs closed down, so I had to go thirty miles away for this.
  • chats1chats1 Posts: 158
    when I turn my ac/heat on, the snowflake comes on. I don't worry about it. When I don't want ac or heat, it's completely off because I turn it off. Where did you get the 40 degrees from. In the beginning when I got the car in August I read that manual 3 times and was looking for what degrees do I turn off the fan. I couldn't find anything so that's why I don't worry about it. My other car said 37 degrees. when my windows get foggy I just put it on defrost and then when they clear I turn it off. Isn't this fun. I decided I'm not worrying about anything on the car. It's under warranty for 3 years and after 3 years I either sell my car or trade it in and get a new one. Now, I'm thinking about what I want to buy next. I have 2 l/2 years to play with different ideas. Don't even call the CAC, they're stupid. I'm glad that I'm not the only complainer!!!
  • I have dual climate control. AC is off when system is off. I don't quite see what the fuss is about.

    Correct me out there if I'm wrong, but most new cars will run the ac unit if the driver chooses any defroster function, and that includes cold weather stuff. Remember, ac removes moisture from air, a good thing even if it is 10 degrees out and relative humity is very low. I think most people don't even realize their ac is on in most models.....
  • dblducedblduce Posts: 58
    chats1, you are correct. i was mistaken when i said my GXP didnt come with OnStar. What i meant to say was that it didnt come w/ the Navigation system. I forgot that Onstar was even installed because I have never used it, nor had any reason to. I have pretty much everything else you could order in it though, except for the Nav system. It even has the Monsoon speaker upgrade, so i dont think that would be causing the hissing. it sounds to me like there is something going on that is being amplified by the speakers, like an entry alert, door open, etc. since i dont have that noise, i guess ill never know.

    The best thing i love about my GXP, other than the POWER, is the fact that there arent many others on the road. i have seen only 1 other, and that was at the end of last summer. i havent seen any others on the road where i live. i love to know that i have a special car that not many have seen before. I really take notice too as to who else drives the kind of car i drive. I used to have a chevy blazer, and after i got it, i immediately started noticing all of the other drivers on the road driving blazers, and was always comparing mine to theirs, lol. im glad i dont have to do that w/ my GXP. even when i see the new mustang gt/cobras on the road, i dont have to lower my head in shame now because i finally drive a car that can def. give them a run for the money! :)
  • chats1chats1 Posts: 158
    I agree with you completely. when I want it on, I put it on, when I want it off, I turn it off. If it's still on, I'm not aware of it. I don't hear anything.
  • chats1chats1 Posts: 158
    I have everything also in my car except for the Navigation system. If I get lost, I use my mouth or get myself unlost!! I never had occasion to use OnStar for help but I do use the phone. You can also access the phone through the Mute button on the steering wheel by holding it down and it connects you to OnStar, besides the rearview mirror. I also love this car because you don't see yourself coming and going. I have only seen one in a parking lot since I got mine and last week a fellow stopped me in the garage where I park at work and asked me how I liked the car. He just ordered one. He said it's really really nice and he loved my color (Dark Red Cherry Metallic).
  • sahoward1sahoward1 Posts: 19
    This forum has been about as much help as CAC. Understand this concept, the fan/heat/AC system should not default to the snowflake. It should default to where the driver left it--or off. If it truly is meant to defog the windshield, then shouldn't it be programmed to come on only in defog mode? I could live with that. Personally I think this is a screw up. I think a foreign engineer programmed this and used 40 degrees thinking it was Celsius. That would make sense, the AC should come on automatically if it's over a 100 degrees. That would be a great safety feature. And I think the sensor and the programming mechanics are in a sealed unit, so it's not financially feasible for GM to offer buyers a re-program or a new sensor. And regarding the OnStar hissing, I am starting to get real paranoid. Do you realize the FBI, or someone stalking you would know exactly where you are with this car? Do you think Tony Soprano has OnStar in his Escalade?
  • gxpjoeypgxpjoeyp Posts: 38
    Well i found the hissing noise in my 06 gxp,its not onstar,it was my cat hissing at the rattlesnake that apparently came standard......ha ha ha. 588 miles n counting......o yea i managed to take off those unsightly GM badges on the front fenders,thanks zoomandyzoom and erichthecatt.
  • rayainswrayainsw Posts: 2,614
    “This forum has been about as much help as CAC. Understand this concept . . .”

    I think that:

    1. Several people here (including me) do understand that some series of design parameters and \ or judgment errors have resulted in the A/C compressor running at times we don’t think it ought to run. Now that I understand the behavior, I do simply turn the A/C off when I don’t want it running.

    2. No one here now has a huge problem with either the hiss or the overly aggressive A/C engagement programming.

    I have owned and driven so many cars I have lost count (in about 40 years with a driver’s license) and I cannot recall one that did not exhibit at least a couple of annoyances. Some small & some rather large. These 2 items (and again I will grant that if I ruled GM they would not have made it to production) fall into the annoyance category – for me. Heck, I am annoyed that my driver’s door often does not stay at the full open detent \ position by itself. Oh, well . . .

    The fact that no one here has a ‘remedy’ for the 2 issues you raise is apparently also an annoyance to you.


    If a solution existed, I believe that it would have been posted here or on another Board I follow closely. I don’t believe that anyone is intentionally withholding information.

    And perhaps Tony will now use his wife’s Porsche SUV (something I would have bet serious money 20 years ago would never exist) when he has a concern about OnStar surveillance.

    - Ray
    Feeling any annoyance fade far behind when I open the throttle . . .
  • chats1chats1 Posts: 158
    You are not being fair at all comparing this forum to the CAC. This forum is extremely helpful and has been very helpful to me. Everyone tries to help each other, and as Ray just stated, no one is withholding info. If we have it, we share it. Now to the CAC -- they are worthless, useless, stupid. They are not engineers but more like telemarketers. They look in the manual and call the dealer while you are on "Hold." Any idiot can do that!!! I don't even call them anymore. So, I think you are being very unfair with your statement critizing this forum. All we are trying to do is be helpful. We didn't manufacture this car. When I want heat, I use my automatic climate control or when I want a/c. Then I turn it off. So, I don't have any problem. If this forum bothers you, you shouldn't participate in it. And, I'm not being fresh either, just realistic. I enjoy this forum very very much and get lots of pointers.
  • chats1chats1 Posts: 158
    I don't see the problem with those GM badges, but I know others have criticized them also. Did the removal of the badges leave any mark on the paint?
  • dblducedblduce Posts: 58
    One of the main reasons I review this forum is to keep up on any information about my GXP. I dont rely on GM anymore for that information due to my last vehicle.

    I purchased a 2005 Chevy Equinox in July 2004. It was a great vehicle to start out, but they i quickly found problems with it. The main one being with the heating system. After only a few thousand miles on it, I was browsing the Equinox forums, and discovered that many drivers had issues with their coolant. So, i decided to check mine, and it looked literally like chocolate syrup! needless to say, i contacted dealer about it, and they said that "GM" hadnt issued any service bulletins about it, so dont worry about it. After a few months of studying the forums though, i found that it was a coolant hose problem; they were manufactured overseas somewhere, and they didnt use the proper preperation to treat the hoses, and it was reacting w/ the dexcool coolant. After many calls to my dealer, they finally contacted the right people and replaced my hoses (all 7 of them!) to fix the problem. Of course, i traded that vehicle in June 2005 for my GXP though, and i've never looked back!

    Forums like this are a great way to share information with actual owners, and keep the dealerships out of the loop. They are only as good as what GM lets them be.
  • sahoward1sahoward1 Posts: 19
    I too, have owned many cars and most have had minor annoyances. But... the GTP I traded in was my favorite car of all time...better than my previous Bonneville. That GTP was perfect and I loved it. The only thing that happened was it got up to 69K miles, so alas, I needed a new car. And I guess I thought I was going to like this blue-green crystal as much. And I guess I didn't think I was going to have to accept this stupid AC programming, especially since my salesman told me it could be re-programmed. I'm disappointed I didn't find a solution here, but satisfied that evidently none exists. One more question if you don't mind.... does anyone know how to get past CAC? Is there another level to take this?
  • rayainswrayainsw Posts: 2,614
    "especially since my salesman told me it could be re-programmed"

    You believe what a sales dweeb told you?
    - Ray
    Astonished . .
  • chats1chats1 Posts: 158
    Why don't you ask the Service Manager for the name of the representative for your dealership. Maybe he could help you. There is always the BBB (their number is in your manual). GM participates in the BBB. I didn't bother though when I was doing all my complaining about the hissing/humming because I figured I would get nowhere. My hissing/humming is so minor I just ignore it now since it goes off after 15 seconds and does not interfere with the performance of my radio/cd player. when my nephew listened to the hissing/humming sound he called it "static." But, my problem was I was fighting on "principle." GM was aware of the problem with the 2005 GXP's and yet put the same problem in the 2006 GXP's. I didn't even know I had this problem until someone on this forum told me I did. He said open your door and put your ear next to the speakers, you'll hear it. And he was absolutely right. I did! That's why I think this forum is great. Ray is very very helpful as is Robert Hammen, but we don't hear from him much. He helped me too alot re the tires. And he was correct. I have also written to two people at GM and received NO reply.
  • sahoward1sahoward1 Posts: 19
    I had been doing business with a small, country dealer since 1977, and yes I did trust them. I took my car in rarely and for small problems that were fixed promptly the first time. They even gave me a ride to work when I had to leave my car. Last fall they closed down; the father/owner became too ill and I don't think the kids wanted to work that hard. So the dealership was sold to Hundai. I miss their personal, friendly, honest service. Anyway, it's a lovely day here in New England and we're coming into AC season. Who knows what matters may concern us by September. I'm satisfied that if a solution existed for the AC (re-program or new sensor) someone here would have found it. I plan to write letters on this topic and if I get anywhere, I'll let everyone know. By the way, I think the snowflake default is far more annoying that the hiss or the GM badge.
  • billgxpbillgxp Posts: 13
    Sorry to hear the AC issue is ruining your GXP experience. I am not sure how carefully you read the owners manual or how much you have experimented with the system, so let me share these thoughts. I have a 2005 GXP with the manual climate control and the AC light did not come on all the time in the winter. A review of the owners manual for both the manual and auto climate control systems indicate that "the system will automatically turn off the recirculation and run the air conditioning compressor, unless the outside temperature is near or below freezing." when the selector is set for FLOOR/DEFOG or DEFROST. (In the case of the manual system it indicates 40F vs. freezing). Have you tried using the selector in the VENT, BI-LEVEL, or FLOOR positions and see if that continues to activate the AC compressor? The other important thing to understand is both climate control systems are very sophisticated pieces of equipment. If the compressor is activated it is by design and mostlikely serving its intended purpose. Maybe having the compressor on is more of a concern with higher fuel costs, but my guess is the effect is minimal (the car does have a V8). Also if you check further back in this forum there was a link posted that led us to more detailed info about the operation of the climate control system, specifically in regards to the parameters it follows during remote start. Hope this helps.

    For anyone who might care, I found that when listening to a CD, if you want to fast forward or reverse the song you are listening to you can press and HOLD the up or down button on the left side of the steering.

    No complaints about my GXP!!
  • gxpjoeypgxpjoeyp Posts: 38
    No but cuz im such a yutz sometimes,as i was removing the one on the drivers side,i managed to accidently put a nice 1" scratch on the fender,i feel like i wanna cry.....touchup time.
  • chats1chats1 Posts: 158
    Try Meguiar's Wax. You may be able to get the scratch out unless you took the paint off. See, that's why I wouldn't fool around with those badges. Actually, I know other people on this forum also don't like them. They don't bother me though. I'm too busy looking at the GXP badges to notice those little GM squares. I love them!!!
  • dblducedblduce Posts: 58
    i guess a good test would be have someone put their ear to the speaker, and have someone else push the Onstar button to activate it, and see if the hissing stops.

    another test one could try would be to remove the fuse for the interior lights and/or the onstar to see if that has any effect on the hissing as well.

    i would tend to believe it has something to do w/ the chime that plays when you leave the key in the ignition and open the door. doesnt that sound get produced thru the speakers as well? if so, isnt there a setting in the manual to turn this chime off? that could be another possibly of what is causing it.
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