[danieljag1]

I have a 2000 Mustang GT manual tranny and 145,000 miles. Recently I got the A/C up and working again due to a low pressure switch being faulty. Since then, anytime I am coming to a complete stop a loud shaking noise goes off in the rear of the car. I've been able to tell that it happens the same time my RPMs return to idle. This does not happen, however, when the A/C is off. Also, when I'm on the highway theres is a loud vibration when at 64-66 MPH. I have no idea what causes that? Any healp will be greatly appreciated.

 

[yellasnake]

I find it odd that your a/c would affect the rear-end since it all resides up front. The only wild guess I would make is that the a/c is making an engine wobble or vibration that is being transmitted to the rear end. Maybe check the compressor for alignment or your motor mounts.

 

[tobe1424]

what yellasnake said is a good start..

I think this might be one of those things that I caused my several components at once. Check your alignment, driveshaft, subframe mount(notorious for going bad) just in case.

Does this noise sound like a important component or like an interior piece that is vibrating?

 

[danieljag1]

it sounds like an interior peice vibrating. ive checked over and over again and cant find anything. the only other thing it could be is my rear speakers moving around, which i have not checked yet.