Clunk Sound when letting go of Gas

[mkmk]

Hello, hoping I could get some help.

I own a 2008 328xi and fell in love with BMW's that I started looking for a E28. Purchased a 1983 533i, in great condition.

I know I shouldn't have, considering how Not-So-handy I am.
I just couldn't help it...... they look so nice.

So far, from reading the postings on MyE28, I have fixed fast blinking signal lights (faulty wiring), and reset system lights.

Now, I've read some postings regarding the clunking sound, which most people are claiming to be Rear Differential.
In my case though, the clunking sound does not happen when breaking, turning, or clutching (mine is an automatic), but when letting go of the gas while driving.

Would you think this is still due to the rear differential?

Would appreciate your help!

[Bimmerguy2002]

check your dogbones, and subframe bushings if your diff mount is in good condition already.

[tn535i]

Does it also clunk if you put it in reverse? Diff mount gone bad will clunk with either engine braking or reverse.

I don't know what clutching is on an automatic btw But a downshift would be like exageratted engine braking and may cause a clunk also if the diff mount is bad.

[mkmk]

Does it also clunk if you put it in reverse? Diff mount gone bad will clunk with either engine braking or reverse.

I don't know what clutching is on an automatic btw But a downshift would be like exageratted engine braking and may cause a clunk also if the diff mount is bad.

Hahah, yes, there's no clutch in mine. I was just trying to list the things they do, before the "clunk" happens.

The funny thing is, no clunk when in reverse or when I break or turn. Only when I let go of the gas pedal while driving. When I let go of the gas very very very gently, I may get by without hearing the clunk. The sound isn't that significantly loud, perhaps like the sound of someone closing the gas flap lid, while you are sitting inside the vehicle.

[Amos830]

CSB

[Dan_Wright]

Sub frame bushings, dog bones, or differential mount. I had the same problems (and more) and my car needed all of these things.

I will add that if your sub frame bushings are bad, you will feel other noticeable symptoms, like the rear end being loose in general.

[Chimi-Changa]

Hi I had something similar happen when I was adjusting the throttle position sensor (tps) mine is a 5 speed though. After readjusting my throttle plate, and sensor- smoothed it out for me. Keep digging- this forum and a Bentley will help

[Squire68]

I'm thinking CSB. Mine felt like a big MagLite rolling forward and hitting the seat brackets when I lifted the throttle. I actually kept checking for something rolling around the back seat area. I was able to confirm by looking forward along the drive shaft without removing the heat shield or exhaust.

[mkmk]

Thank you everyone for your experience/expertise.

[ASLAN]

I agree with amos and squire, it's prob your center support bearing ready to go. Once it does, it will be very loud; the sound of your drive shafting banging on the floor pan.

[slimdevil27]

Pop the hood and watch the engine. Set the ebrake and power brake it, hold the brake and give it a little gas, in drive to about 1000 rpm and then shift to reverse and back to drive. If that produces the sound then grab a sixpack as bait for an unsuspecting friend. Jack up the rear end, at the subframe, secure with jack stands and repeat watching the diff and driveshaft, no need to go under the car.

If no noise then shut it off and visually check everything they said.

Where does the noise come from? Front, rear, under your feet?