dhouston Posted October 5, 2008 Report Share Posted October 5, 2008 Hello All - I have a quick question. I have an '08 Shelby GT500 coupe - Currently has 1900 miles. Since new, about every 200 miles or so, I am hearing a thud or thump noise coming from the front end area. It seems to occur when the car is first started and not moving. It is a rather loud noise, lasting about 1-2 seconds and quits. It doesnt do it everytime I drive it, just about once a month maybe. It seems to be coming from the drivers side front. I dont know if it is a suspension part in a bind, a motor mount or something else? Anyone have this issue come up yet? I guess I will take to a Ford dealer and see, but I have no clue what is causing this. So, I wanted to get some opinions to direct the tech prior to taking it in. Any help is greatly appreciated. Dave Link to comment Share on other sites More sharing options...
enormous Posted October 5, 2008 Report Share Posted October 5, 2008 A little rust on the brake rotor and pads will cause a slight freeze. Not driving it or washing it and letting it sit will case this momentarily. I wash mine requently. If it sits overnight I get some rust build up on the rotor. As soon as I start it I get the same noise you describe. Hope that helps. Nothing to worry about. Link to comment Share on other sites More sharing options...
DDT Posted October 5, 2008 Report Share Posted October 5, 2008 I have heard the same noise and wonder if it is a strut noise as it sounded the same on my 05 GT before they changed the shock struts............ Link to comment Share on other sites More sharing options...
daveh70 Posted October 6, 2008 Report Share Posted October 6, 2008 Maybe it's the noise that occurs during idle. It's supposed to have that sound due to the high performance nature of the drive train. Dave Link to comment Share on other sites More sharing options...
ingram4868 Posted October 6, 2008 Report Share Posted October 6, 2008 I can't imagine that to be a normal condition. While I do not read every post on every website I don't recall others bringing this up. Link to comment Share on other sites More sharing options...
daveh70 Posted October 6, 2008 Report Share Posted October 6, 2008 In the manual for the GT500 in the glove box, I recall there's mention of a slight rattle sound when the car is at idle. Dave Link to comment Share on other sites More sharing options...
DDT Posted October 6, 2008 Report Share Posted October 6, 2008 In the manual for the GT500 in the glove box, I recall there's mention of a slight rattle sound when the car is at idle. Dave I believe the noise is described as a "THUMP" sound from front floor area????????? Link to comment Share on other sites More sharing options...
ingram4868 Posted October 6, 2008 Report Share Posted October 6, 2008 In the manual for the GT500 in the glove box, I recall there's mention of a slight rattle sound when the car is at idle. Dave When you mentioned the glove box I remembered my 84 Mustang had a sticking air box damper door that was located between the center console and the glove box. As the vacuum built up shortly after starting the car the damper door would pop open. It's just a guess because I'm not even sure that the controls are vacuum operated anymore. Link to comment Share on other sites More sharing options...
dhouston Posted October 6, 2008 Author Report Share Posted October 6, 2008 Thanks for all the input so far. I dont think it's brake rust, as the very first time I heard it, I had driven the car about 30 miles, got out and ran into a store, came back out and started the car and then heard a big thud. Everytime I hear it, I am not even moving. Usually it is right after I start it up, within 10 seconds maybe. Ive never heard it driving or pulling into a driveway, etc. It doesnt seem like a suspension issue or it should do it while in motion. My car as one of the 'on hold' cars with the wiring harness issues back in Oct/Nov '08. I am hoping it isnt an engine firing issue. It runs great, and has never missed. I wouldnt think its engine related. Seems like something in a bind, and then pops and releases, like maybe a strut or even possibly related to power steering part? Its kind of loud so has me concerned. Its like something under pressure. Very strange, it only happens about every 4-6 weeks once and then fine. I dont smell anything, dont see any smoke, or any leaks anywhere. Link to comment Share on other sites More sharing options...
DDT Posted October 6, 2008 Report Share Posted October 6, 2008 I have also heard this the way you describe on my GT500 but not as often......... Same noise as on my GT before they replaced the shock struts and there is a TSB on it I think?????????? Link to comment Share on other sites More sharing options...
MichaelFreedman Posted October 6, 2008 Report Share Posted October 6, 2008 I have also heard this the way you describe on my GT500 but not as often......... Same noise as on my GT before they replaced the shock struts and there is a TSB on it I think?????????? I have heard the same thing on my 2009. I think it may be the heater box closing up when it's on recircuilate. It only happens once and seems to only happen at startup for me. Mike Link to comment Share on other sites More sharing options...
Wilmmr Posted October 6, 2008 Report Share Posted October 6, 2008 I've heard the same thing on mine and I've had it only a month today. What I hear is like a bang almost, more than a thump, I jumped the first time I heard it. I could feel it thru the floor board. I've always thought it was coming from the brakes, it hasn't damaged anything. I always set the parking brake, maybe tension being released? Anyway its done it about 3 times and my 500 is my daily driver so it is infrequent. Hope it helps knowing your not alone in hearing this, as to what it is, I have no idea. Link to comment Share on other sites More sharing options...
ingram4868 Posted October 6, 2008 Report Share Posted October 6, 2008 I've heard the same thing on mine and I've had it only a month today. What I hear is like a bang almost, more than a thump, I jumped the first time I heard it. I could feel it thru the floor board. I've always thought it was coming from the brakes, it hasn't damaged anything. I always set the parking brake, maybe tension being released? Anyway its done it about 3 times and my 500 is my daily driver so it is infrequent. Hope it helps knowing your not alone in hearing this, as to what it is, I have no idea. Perhaps your dealership can place a logging device on your car to see if it is engine related Link to comment Share on other sites More sharing options...
dhouston Posted October 6, 2008 Author Report Share Posted October 6, 2008 I've heard the same thing on mine and I've had it only a month today. What I hear is like a bang almost, more than a thump, I jumped the first time I heard it. I could feel it thru the floor board. I've always thought it was coming from the brakes, it hasn't damaged anything. I always set the parking brake, maybe tension being released? Anyway its done it about 3 times and my 500 is my daily driver so it is infrequent. Hope it helps knowing your not alone in hearing this, as to what it is, I have no idea. Yes, the sound I hear too can be described as a bang....seems to be on the drivers side and definitely can feel it through the floorboard. Yours sounds consistent with what I am hearing. It's a scary sound even though infrequent, I can't believe this would be normal on a new car. I'm going to take mine to a Dealership this week. I will post again once I have it looked at. The problem is getting it to do it while they have it in the shop. It is so irregular, that it is going to be difficult to hear unless they drive it for a month....which isnt going to happen. But I'm still going to see if there is a TSB or history of fixes for this. Link to comment Share on other sites More sharing options...
ingram4868 Posted October 6, 2008 Report Share Posted October 6, 2008 The computer logs backfires but I think it takes more than 1 to throw a code. Link to comment Share on other sites More sharing options...
VaporDude Posted October 6, 2008 Report Share Posted October 6, 2008 I have noticed this as well on my car. The only thing that I can think of is something that operates off of vacuum. I had a truck that did this but it was a 4 wheel drive so I don't think it would be related. Link to comment Share on other sites More sharing options...
Wilmmr Posted October 6, 2008 Report Share Posted October 6, 2008 Well what we have established is that it is a common occurrence among the GT500, so it is either a design flaw or a consequence of the engine/drivetrain which is unique to the 500. I have not heard of this with the regular GT. I'm going to get an oil change at 1,000 miles, I'll ask the SVT tech about this and the clutch drag issue and will post whatever they say. Link to comment Share on other sites More sharing options...
VaporDude Posted October 6, 2008 Report Share Posted October 6, 2008 I am sure there are alot of components that the GT does not have compared to the 500. My wife has a GT and I know her car has never done this and the 05 GT I traded in on to this 500 did not do it either. So I would say yes it is to the GT500 specific. I'm just wondering if it has anything to do with the super charger. Link to comment Share on other sites More sharing options...
blown9350lx Posted October 8, 2008 Report Share Posted October 8, 2008 I heard this same noise on my car start it up then a thump sounds like its comming from the lower dash area. I sat in my friends 03 cobra and it did the same noise they said it was the ac box when vacum builds up the panel moves and makes a thump noise so far its a normal thing I wouldnt worry about it. Link to comment Share on other sites More sharing options...
Snake Handler Posted October 8, 2008 Report Share Posted October 8, 2008 I have not heard it on my GT500, however I just rented a 2009 V6 Mustang and drove it for 5 days and I heard the "thump" twice. First time I heard it I thought one of the front wheels fell off the car. The car had 1900 miles on it. Link to comment Share on other sites More sharing options...
mciarochi Posted October 9, 2008 Report Share Posted October 9, 2008 Did you check for cats? They will thump right after you start the car. It doesn't sound normal, whatever it is. Link to comment Share on other sites More sharing options...
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