1loudredfire

I have been hearing this wierd clunk or pop sound after I start my 07 GT. seems to happen when car has been brought up to temperature and then is turned off and sits for 5 min or so. The noise happens about 5-10 seconds after the engine fires but it does not happen every time although it is starting to happen more and more. Does this happen to anyone else or does anyone think I should be concerned. Please let me know what you think. By the way the car is basically stock so there is no mod causing this.

hammeron

i think it's dealership time.

if it's a misfire, it could be a spark
plug or a fuel injector

1loudredfire

I don't think its a misfire, its just one loud clunk then it won't happen again until I turn the car off let it sit and then turn it back on. The only other thing that happens is when my engine is cold it started to backfire on the first 1-2 shifts since I changed my exhaust to SLP loudmouths.

1loudredfire

has this happened to anyone else at all, please give me any feedback, I am concerned if I need to take it to get looked at or not.

thewarmachine

Mine makes the clunking noise a few seconds after startup also. I'm not concerned about it. I don't know what it is.

moriel248

Sort of a metallic thunk like something shifting? I went to the store the other day, got stuff came back out, started the car and like 5 seconds later mine made that noise. Was the first and only time, I wondered what it was. Can't find anything wrong. I'd be curious to know though.

Edit: '07 also for what it's worth.

thewarmachine

Mine doesn't do it every time. I'm wondering if it's just the left front strut breaking loose from it's position as my weight and the car engine vibration shake it loose. I don't weigh much (155 lbs), so maybe it takes the car's starting up to do it, not just my sitting down in the seat.It kind of sounds like someone thumping the tire hard. Anyway, like I said, it's no big deal.

A_J

I'm on the hunt for this one too - I think I've got it narrowed down to the suction accumulator for the climate control.

Does it sound like it's coming from the drivers side front? Try this (this works with mine), turn the climate control to off when you turn off the car, then go restart after 5-10 with the climate control off and see if it still does it. On mine, it never makes the sound if I do this, but if I leave the climate control set to on (any setting) when I shut the car off, it almost always does the noise when restarting after 5-10 min. Further, it'll do it when the car is absolutely still, telling me it's not suspension.

I even triedleaving the CC on and starting the car, going out and watching the suction accumulator, and you can see and hear when the CC gets going and the sound happens - the lines going to the suction accumulator shake when it happens. At this point I can't tell if the true 'cause' of the noise is the mounting for the suction accumulator being loose, thus allowing normal operation to make a noise, or if something is up with the AC (like slugging, oil, etc.) that's the real cause of the noise.

Since I can now prevent it by happening by turning the CC to off when I shut off the car, I'm not freaking about it - I've got my first service appt in 1000 miles, so I'll wait till then to bring it up for warranty work.