vanzen

I just bought a Gt and it didnt do this at the dealership but it has started to knock when i start the engine. I bought it used. It sounds like the knock is coming from the left door as i try to feel for it. It is only one knock, sometimes I hear the knock before I turn the key all the way to start the engine. Anyone know what it could be? thanks


shaun

AirForcePonycar

What you're describing sounds like what happened with my '06 GT after I installed an aftermarket head unit. Just about everytime I turned the battery on in the car, a loud thud would come from the speaker. I asked the guy at best buy about it, and he said it was just the pre-amp powering up....You're not driving my old mustang, are you? Lol

vanzen

Silver with black stripes from vegas haha i dont know but yeah sounds and feels like it is coming from the speaker

AirForcePonycar

Nope, definitely not me. Haha. Does the car have an aftermarket head unit, or no?

05PRMTX

If its an aftermarket head unit, its the "amp pop" everyone talks about. Can be fixed with a voltage regulator. If its the stock HU im not sure, I guess it could be the same thing still