One knock on startup Mustang Gt
 

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

try turning the ac/defrost off before shutting off the car for the night...both my 06 mustang and my 00 marquis have developed a klunk at startup the first time the ac clutch engages after sitting overnight sometimes...I replaced the bearing on my mercury(it was really bad) but the noise returns a couple times a week at startup/first engagement of the ac clutch...hasnt seemed to hurt anything the last couple years, kinda got used to it...I do check idler/ac pulley bearings more often now, but so far everythings still tight... think the clutch is just glazed and engaging very harshly(my tranny clutch on the 06 is getting grabby/chattery also- its time...)