87 325ic rattle

jnscaldwell · Post by **jnscaldwell** » Wed Mar 02, 2011 3:16 pm

Al, I am going to be working on my E30 most of the weekend. If you want to stop by let me know we can have a look together. You are about 10 mins from me maximum. PM me or I think you still have my e-mail.

Jeff

Al323i · Post by **Al323i** » Wed Mar 02, 2011 3:19 pm

Jeff, Stop by this weekend and take it for a ride to hear the noise for yourself.

I have inspected the suspension, both visually and by pulling and twisting, and saw nothing out of the ordinary.

-Al

kevnj · Post by **kevnj** » Wed Mar 02, 2011 3:24 pm

Al323i wrote:I replaced the shocks and mounts as the first line defense. No change to the rattle.

kevnj asked if I could reproduce the noise while on jacks. I am not sure how I would 'bounce' the car to simulate a pot hole.

-Al

I agree you won't be able to reproduce the problem completely. But while the car is on jack stands you can do a variety of things to see what's going on.

1. Get the rear of the car up on jack stands.
2. Take the rear wheels off.
3. Inspect all the bushings (Subframe and trailing arm). How do they look? If they have never been changed they are shot for sure. It's a big job to change these but man it will make a huge difference in the ride and handling. BMW's eat these bushings up but its also one of the reasons they handle so well while providing a smooth ride.
4. Check the rear springs. Check for corrosion that can lead to a coil being cracked or broken off.
5. Grab the rear end by the discs and see if there is any looseness or play that feels out of the ordinary
6. Use a jack with a piece off wood and jack up each of the rear wheels one at a time. Open the trunk and inspect the rear shock mounts after jacking up each side. Are the rear mounts where they should be or did they move up? Any odd noises as you raised each side? If they are worn or loose there will be some play if you grab the rear shock and shake it. This MIGHT be the problem.

In all honestly I'm not sure what the problem is. Earlier in the thread it sounds like the noise is a "Jingle" but later on it sounded like it might be more of a thud which made me think it was worth checking the rear suspension overall.

On a car with rear drums I had a repair shop do the brakes and the springs for the shoes were not installed correctly and it made sounds like you described. If I recall correctly the rear parking brake on an E30 has shoes that use a spring so that could be a possibility.

Jeff B and I are playing hooky from work this Friday and will be replacing the rear suspension on our E30's. If you are free PM me and you can bring the car and we can listen to the problem live. It's tough to diagnose this stuff without hearing it 1st hand. If Friday doesn't work bring the car to the next meeting and I'm sure someone will be able to single out the problem based on the noise.

kevnj · Post by **kevnj** » Wed Mar 02, 2011 3:25 pm

jnscaldwell wrote:Al, I am going to be working on my E30 most of the weekend. If you want to stop by let me know we can have a look together. You are about 10 mins from me maximum. PM me or I think you still have my e-mail.

Jeff

You beat me to it....I was thinking the same thing.

Al will be in good hands.

colin · Post by **colin** » Thu Mar 03, 2011 10:55 am

This is a common issue with E30s. Check the trunk for a metal toolbox full of tools.

Eurosport · Post by **Eurosport** » Thu Mar 03, 2011 6:06 pm

In the right rear corner of the trunk where the battery would sit in a regular e30 there is a plastic cover, remove it. You will find a big weight that they used for weight distribution. Remove it and your problem will be solved.

Sean D

Al323i · Post by **Al323i** » Thu Mar 03, 2011 9:32 pm

Sean, interesting idea....I will check this in the morning.

-Al

Al323i · Post by **Al323i** » Fri Mar 04, 2011 8:50 am

Sean,

BINGO! I believe the weight was the problem. I did inspect this area a month or so ago, but didn't know that there was anything underneath the painted panel. When I pulled out the weight, one side of the mounting bracket was nearly torn off....i.e. this is why the weight bounced around when hitting bumps.

Jeff C. You have your Saturday morning back.

Thanks everyone for your help.

-Al

kevnj · Post by **kevnj** » Fri Mar 04, 2011 9:45 am

Eurosport wrote:In the right rear corner of the trunk where the battery would sit in a regular e30 there is a plastic cover, remove it. You will find a big weight that they used for weight distribution. Remove it and your problem will be solved.

Sean D

Would have never guessed that. Didn't know the convertible had that extra ballast there in place of the battery.

Al323i wrote:Sean,

BINGO! I believe the weight was the problem. I did inspect this area a month or so ago, but didn't know that there was anything underneath the painted panel. When I pulled out the weight, one side of the mounting bracket was nearly torn off....i.e. this is why the weight bounced around when hitting bumps.

Jeff C. You have your Saturday morning back.

Thanks everyone for your help.

-Al

Glad you figured it out!

jnscaldwell · Post by **jnscaldwell** » Fri Mar 04, 2011 9:54 am

I just learned something new! Thanks Sean for the post and the help!

JeffNJM3 · Post by **JeffNJM3** » Sun Mar 06, 2011 10:38 pm

Eurosport wrote:In the right rear corner of the trunk where the battery would sit in a regular e30 there is a plastic cover, remove it. You will find a big weight that they used for weight distribution. Remove it and your problem will be solved.

Sean D

You da man Sean

, see my pic below, that thing was flopping around in there like an elephant in a glass house! That took care of one of my rattles, only a couple more to go

Jeff

kishg · Post by **kishg** » Sun Mar 06, 2011 11:16 pm

nice going... sean knows what's up!

Al323i · Post by **Al323i** » Mon Mar 07, 2011 9:19 am

Sean,

Thanks again. My weight anchor points look just like's Jeff's. I was amazed how much engineering went into the weight, it's ashame that it's held down with nuts in sheet metal. The weight is sitting on my garage floor...too nice to toss out.

-Al

SmokeyDP · Post by **SmokeyDP** » Mon Mar 07, 2011 12:36 pm

How much does this weight weigh?

Al323i · Post by **Al323i** » Mon Mar 07, 2011 12:58 pm

I haven't taken out the bathroom scale, but I would estimate ~35lbs.

-Al