So I've got an intermittent sound coming from what seems like the front drivers side of the car, and it doesn't seem to fit with the good 'ol front end strut mount thunk, and I'm having a heck of a time coming up with what it may be...

'07 GT, 5sp, built 3/2007, 1750 miles.

Symptom: Pop noise from what sounds like the front drivers side. Rather loud, can feel it in the floor. Sounds kind of like something shifting around. Since I've had the car it's done it probably two dozen times.

When: Only after backing out of a parking spot, and then rolling forward. Within a few feet, happens once. No noise at all after that. Only seems to do it when I've been driving the car some, stop somewhere, and then go to leave after 15 or so minutes. Never happened first thing in the morning that I recall. Happened a few times after I first got the car (a loaner GT I had while waiting for delivery did it once too), and then seemed to go away. Came back a few weeks ago, a few days after I had it up in the air. One of the days, did it 5 times as I was running errands. Then seemed to go away again, but had car in air again last weekend, and did it again a few times yesterday, but not every time.

Working theories: Since I can't get it to reproduce, been having a hard time..

- Checked endlinks and strut mount bolts for tightness - seem ok.

- Now that I pay attention to it, sometimes when backing out I can feel a subtle thump in the pedals when backing out, and every time it does that it makes the sound when rolling forward. One time I had my foot on the brake and I swear I felt a shift in the pedal level. But what with the brakes? Thinking e brake sticking, then letting go when I go forward, I've tried either little e brake when parking or pumping the pedal before going forward - niether has seemed to have any effect - and besides, what would the e brake in the rear have to do with a sound in the front? Only other thing I can think of is some kind of check valve letting off or something..

- The other option, which seems the most reasonable to me, is something with the suspension, but what? Could this just be noise from the spring settling in after being in the air? Could my strut mount be marginal, and I get some shifting going from reverse to forward, and I get no on-road symptoms?

Like I said, since I can't get it to reproduce at all on purpose I'm starting to get a little OCD about it.. I may eventually have the revised strut mounts put on for giggles even if it wouldn't be covered just to see if it goes away... and I'm going to toss a notepad in the car to make note of everytime it happens, but I'm wondering af anybody has had this or has any ideas - thx!

 

This might sound weird, but could it be the aircon pump kicking on/off? I know some make more clunk noises than others, you'rs might be a particularly noisy one. I definately hear/feel mine coming on.

 

I had thought of that, but as far as I know it'd only do it if I have the AC on, which I ususally don't..

 

Did you ever find the cause? Our Mustang is a little over a month old with <700 miles and it has a similar sound. It has occured twice after stopping at a store and getting back in the car. However, ours does it about 30 seconds after getting in the car and closing the doors without touching anything else. The engine had not been started and the pedals, shifter, e-brake, steering wheel, etchad not been touched. All we did was get in the car and close the doors! It was not the windows closing tightly, like they do when the doors are closed, as this had already occured. It can be felt through the floor and sounds like it's coming from the front suspension. It's really not a big problem but certainly makes us curious.