1995 e36 328i mechanical problem? Please help!

[KarlHungus]

I recently purchased a 1995 bmw e36 328i manual coupe. For the last 3 months it has been a pleasure to drive and i really like this car.

Last week whilst driving on the motorway i noticed a knocking sound coming from the under carriage of the car under the rear seat area, 5 miles down the road i noticed that there was a sound coming from the rear of the car which sounded like i was dragging something plastic, if i can try and explain the sound it sounds like something hard bouncing around in a plastic container. I have checked under the car and removed both rear wheels and checked the disc covers etc and it is not these it seems more central like possibly coming from the diff area and this sound only occurs when you drive the car.

Along with the knocking sound which i'm quite sure is the prop shaft knocking and the rattling sound i am very concerned that something is seriously wrong and haven't driven the car since.

A friend of mine recommended this forum and said that i'd possibly get some help here and possibly a diagnosis as to what exactly the problem is.

I normally take my car to a local garage but they have told me they are fully booked for 3 weeks. I will more than likely take the car elsewhere but i'd really like to have a rough idea firstly of what the problem is.

Any help and advice is very much appreciated.

[NealP]

Hello and welcome Karl . Have a look HERE. This shows the rear prop coupling for your car, and my thoughts are that no. 1 may have come loose or broken, or maybe one of the bolts may have sheared, but it mayalso be within the diff itself. Can you tell us where you live so that we can recommend a good independent specialist?

[KarlHungus]

Thanks for the welcome and the advice, i live in Swansea South Wales

[Ronnie]

Did you have any vibrations especially the quicker you went???

[KarlHungus]

Originally Posted by Ronnie

Did you have any vibrations especially the quicker you went???

Vibrations seems worst when first driving off from a standing start. If i accelerate hard the knocking/vibrations dissapear.

[Ronnie]

How low is the rear of the car?

Also check your diff mounts and rear subframe mounting points as well as the prop shaft like already mentioned

[KarlHungus]

Originally Posted by Ronnie

How low is the rear of the car?

Also check your diff mounts and rear subframe mounting points as well as the prop shaft like already mentioned

The rear is low as the car has been lowered i think about 30/40mm. Although i did notice the car was sitting slightly lower on the drivers side at the rear.

This is sounding like a serious problem *gulp*

[Ronnie]

Do the rear wheels sit in at a angle at the top more than the bottom?

And have you checked to see if it has indeed got lowered springs on it?

Don't worry about it sitting slightly lower one side as this is common

[KarlHungus]

Originally Posted by Ronnie

Do the rear wheels sit in at a angle at the top more than the bottom?

And have you checked to see if it has indeed got lowered springs on it?

Don't worry about it sitting slightly lower one side as this is common

Actually i mentioned to the seller when i bought it that the wheels looked like they were more inward at the top like the camber was offset, they definately do sit at an odd looking angle like you mentioned. I havent checked to see if they are lowered springs.

How would i know if they are lowering springs? (sorry im somewhat of a car noob)

[Boostist]

Originally Posted by KarlHungus

I recently purchased a 1995 bmw e36 328i manual coupe. For the last 3 months it has been a pleasure to drive and i really like this car.

Last week whilst driving on the motorway i noticed a knocking sound coming from the under carriage of the car under the rear seat area, 5 miles down the road i noticed that there was a sound coming from the rear of the car which sounded like i was dragging something plastic, if i can try and explain the sound it sounds like something hard bouncing around in a plastic container. I have checked under the car and removed both rear wheels and checked the disc covers etc and it is not these it seems more central like possibly coming from the diff area and this sound only occurs when you drive the car.

Along with the knocking sound which i'm quite sure is the prop shaft knocking and the rattling sound i am very concerned that something is seriously wrong and haven't driven the car since.

A friend of mine recommended this forum and said that i'd possibly get some help here and possibly a diagnosis as to what exactly the problem is.

I normally take my car to a local garage but they have told me they are fully booked for 3 weeks. I will more than likely take the car elsewhere but i'd really like to have a rough idea firstly of what the problem is.

Any help and advice is very much appreciated.

Hmm. Heres my advice

Jack the back of the car up and support on axle stands.
Then grab the propshaft and one of the the rear driveshafts....now hold them both and turn them opposite directions to test how much play there is between them (to see how much play is in the differential gears)

Do this for both driveshafts. There shouldnt be more than a few mm of rotation until the diff stops you turning the shafts.

Then I would read the howto guide in the E36 tech guides forum (sub suction above this forum) on RTABS - rear trailing arm bushes.
Get a big screwdriver between the rear trailing arm and the chassis and see if yo can find any play in the joint.