Battery woes and a thump under car

rmousir · 05-15-2015, 09:51 AM

hi All,

First time poster here.

I recently picked up a sweet little number. A 2006 z4 3.0SI. Silver with black interior. hard top, cover, and only 44k on it. I drove 5 hours to pick it up and drove it home two weeks ago.

So being very new to these cars I've tried to read everything I can to get to know what it takes to enjoy this car and how to take care of it. Well now I've ran into two 'issues'.

First issue. The battery is letting me down. Currently I have a BMW 560cca battery in there. I suspect its more than a few years old and I know the previous owner didn't drive the car much. I suspect that its old and simply needs replaced. I've done my home work and I believe I will go with a H6-AMG or a H7-AGM replacement battery this weekend. I've read that I need to reset the computer.. and I've read I don't. I suspect this will be a simple disconnect the neg.. then the pos.. then the vent tube.. take the battery out.. reverse on install.. and done.. Do I really need to take the car to BMW to have the computer reset?

Second issue. On sharp corners taken with speed I head a simple knock under the car. happens on both right and left turns. I suspect its the exhaust moving about. Thoughts on this? I will get under the car in the coming weeks to take a look..doesn't seem to be a 'its broken' issue.. just something moving that shouldn't.. from a quick look (and you can't see much under there from the side) I think its the exhaust moving. Thoughts?

Thanks so much fellow Zed'ers!

Richard
Ohio

JCF · 05-15-2015, 09:57 AM

I don't believe dealer intervention is needed when changing the battery.

Where is your thump coming from? Front or back? I'd be more suspicious that it's bushings somewhere than a swinging exhaust.

rmousir · 05-15-2015, 09:59 AM

Thanks for the reply!

I agree.. Can't believe the dealer is needed for a battery replacement. hope that is the case. I'll be pretty upset should it be more complicated than that.

The thump sounds like its coming from under the drivers seat floor.

JCF · 05-15-2015, 10:16 AM

I'd have the front control arm bushings and the sway bar bushings checked. Seems like those wear out fairly consistently.

inTgr8r · 05-15-2015, 10:16 AM

Diagnostics are never easy without actually seeing the situation,
however, it seems that the RTABs (rear trailing arm bushings) may be the issue.

You are basically sitting right on top of the right rear RTAB and would definitely feel it through the car seat.

Are you seeing any abnormal rear tire wear, such as inner cupping?
That is also an indication of RTAB issues.

XMetal · 05-15-2015, 10:18 AM

Battery registration is NOT needed on our E85/E86 platform as we do not use the MOST bus => http://www.motor.com/article.asp?article_ID=1479

WestCDA · 05-15-2015, 10:21 AM

Battery will be H5 (Group 47) or H6 (Group 48) - not H6 or H7. Check the existing battery label to know which, or if necessary measure the width.

The battery well will accommodate either size, but the hold down clamp adapter (right side, lower) supplied with your car is sized to fit one of those battery group sizes only. If you want to change from one size to the other, you can buy the correct BMW adapter piece for a few dollars.

rmousir · 05-15-2015, 11:01 AM

Quote:

Originally Posted by WestCDA

Battery will be H5 (Group 47) or H6 (Group 48) - not H6 or H7. Check the existing battery label to know which, or if necessary measure the width.

The battery well will accommodate either size, but the hold down clamp adapter (right side, lower) supplied with your car is sized to fit one of those battery group sizes only. If you want to change from one size to the other, you can buy the correct BMW adapter piece for a few dollars.

Thank you.. I will take my current battery into the shop with me when I purchase it to confirm I have the correct size and everything matches up. H5 or H6. Good to know!

rmousir · 05-15-2015, 11:48 AM

Quote:

Originally Posted by inTgr8r

Diagnostics are never easy without actually seeing the situation,
however, it seems that the RTABs (rear trailing arm bushings) may be the issue.

You are basically sitting right on top of the right rear RTAB and would definitely feel it through the car seat.

Are you seeing any abnormal rear tire wear, such as inner cupping?
That is also an indication of RTAB issues.

No tire wear but the tires are brand new. I did hear it once when pulling out of my driveway as well. sort of a pop when the rear wheels came down off the drive to the road. If I can get my car up on ramps, how would I check the RTABs to be certain?

rmousir · 05-18-2015, 01:10 PM

How would I check the RTABs to be certain?

chickdr · 05-19-2015, 11:03 AM

Also check the black strut bars under the hood. Typically this popping sound emanates from the center of the dash, but it wouldn't hurt to make sure the bolts/nuts are snug.

rmousir · 05-19-2015, 01:00 PM

Quote:

Originally Posted by chickdr

Also check the black strut bars under the hood. Typically this popping sound emanates from the center of the dash, but it wouldn't hurt to make sure the bolts/nuts are snug.

Thank you. I will do that.. I was reading and got the impression that there are frame stiffening bars under the car that often make this noise. Any thoughts there? Is this something I can check my self?

The HACK · 05-19-2015, 01:20 PM

Quote:

Originally Posted by rmousir

How would I check the RTABs to be certain?

Take them off and visually inspect. Or stick a giant crowbar between the rear trailing arms and see how much it deflects, and when it deflects does it make that "thump" noise as felt in car.

rmousir · 06-24-2015, 10:51 PM

Hi guys. I've been out of town for a while but I'm back and took my car to work today and the noise is still there and it sounds like both sides. I suspect a bush or a pair of bushings. I've done my reading and I think I know what to check. I plan on putting the car up tomorrow and I hope I can find the cause.

If I am correct, I will be replacing bushings, I just don't know which yet. Does anyone have a suggestion on the proper tool to use for that?

Anything I should check beside bushings while I have the car up?

Thanks.

StickMon · 06-25-2015, 01:05 PM

I just picked this up second hand from another forumite.
There's also this, but it looks a little cheesy.

rmousir · 06-25-2015, 05:03 PM

OK.. Got the back of the car up. I think I found the problem. Everything looks tight except for the lower bushings on both sides on the rear assemblies. Not sure what the proper name is for these but if I use my pry bar on the lower control arm that connects to the rear spindles you can see the bushings are pretty cracked up and I'm pretty sure it shouldn't be and I believe this will cause my noise when I'm tossing my car around. I've attached the picture.

So my questions are:
1. Am I correct, these bushings look bad? Both sides look like this.

2. How hard is this to change?

3. Is this called the rear lower control arm bushing?

4. I suspect I will need a bushing press tool. What do you recommend?

Thanks very much for any and all suggestions and comments.

Richard

05-15-2015, 09:51 AM	#1
rmousir Private 3 Rep 65 Posts Drives: 2006 Z4 3.0si Join Date: May 2015 Location: Ohio iTrader: (0)	Battery woes and a thump under car hi All, First time poster here. I recently picked up a sweet little number. A 2006 z4 3.0SI. Silver with black interior. hard top, cover, and only 44k on it. I drove 5 hours to pick it up and drove it home two weeks ago. So being very new to these cars I've tried to read everything I can to get to know what it takes to enjoy this car and how to take care of it. Well now I've ran into two 'issues'. First issue. The battery is letting me down. Currently I have a BMW 560cca battery in there. I suspect its more than a few years old and I know the previous owner didn't drive the car much. I suspect that its old and simply needs replaced. I've done my home work and I believe I will go with a H6-AMG or a H7-AGM replacement battery this weekend. I've read that I need to reset the computer.. and I've read I don't. I suspect this will be a simple disconnect the neg.. then the pos.. then the vent tube.. take the battery out.. reverse on install.. and done.. Do I really need to take the car to BMW to have the computer reset? Second issue. On sharp corners taken with speed I head a simple knock under the car. happens on both right and left turns. I suspect its the exhaust moving about. Thoughts on this? I will get under the car in the coming weeks to take a look..doesn't seem to be a 'its broken' issue.. just something moving that shouldn't.. from a quick look (and you can't see much under there from the side) I think its the exhaust moving. Thoughts? Thanks so much fellow Zed'ers! Richard Ohio
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05-15-2015, 09:57 AM	#2
JCF Second Lieutenant 32 Rep 217 Posts Drives: 07 Z4 M Coupe Join Date: Jan 2015 Location: Charlotte, NC iTrader: (0)	I don't believe dealer intervention is needed when changing the battery. Where is your thump coming from? Front or back? I'd be more suspicious that it's bushings somewhere than a swinging exhaust.
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05-15-2015, 09:59 AM	#3
rmousir Private 3 Rep 65 Posts Drives: 2006 Z4 3.0si Join Date: May 2015 Location: Ohio iTrader: (0)	Thanks for the reply! I agree.. Can't believe the dealer is needed for a battery replacement. hope that is the case. I'll be pretty upset should it be more complicated than that. The thump sounds like its coming from under the drivers seat floor.
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05-15-2015, 10:16 AM	#4
JCF Second Lieutenant 32 Rep 217 Posts Drives: 07 Z4 M Coupe Join Date: Jan 2015 Location: Charlotte, NC iTrader: (0)	I'd have the front control arm bushings and the sway bar bushings checked. Seems like those wear out fairly consistently.
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05-15-2015, 10:16 AM	#5
inTgr8r Lieutenant General 2426 Rep 11,667 Posts Drives: M2 Comp Join Date: Mar 2006 Location: Toronto iTrader: (10)	Diagnostics are never easy without actually seeing the situation, however, it seems that the RTABs (rear trailing arm bushings) may be the issue. You are basically sitting right on top of the right rear RTAB and would definitely feel it through the car seat. Are you seeing any abnormal rear tire wear, such as inner cupping? That is also an indication of RTAB issues. __________________ '21 M2C Hockenheim Silver '18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold)
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05-15-2015, 10:18 AM	#6
XMetal Colonel 1125 Rep 2,860 Posts Drives: Anything Join Date: Apr 2010 Location: SoCal iTrader: (0) Garage List 2008 Z4M Coupe [10.00] 2018 Audi S3 [0.00] 2004 X5 [8.50]	Battery registration is NOT needed on our E85/E86 platform as we do not use the MOST bus => http://www.motor.com/article.asp?article_ID=1479
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05-15-2015, 10:21 AM	#7
WestCDA Second Lieutenant 7 Rep 273 Posts Drives: 2006 Z4R 3.0si Join Date: May 2011 Location: Calgary, Alberta iTrader: (0)	Battery will be H5 (Group 47) or H6 (Group 48) - not H6 or H7. Check the existing battery label to know which, or if necessary measure the width. The battery well will accommodate either size, but the hold down clamp adapter (right side, lower) supplied with your car is sized to fit one of those battery group sizes only. If you want to change from one size to the other, you can buy the correct BMW adapter piece for a few dollars.
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05-18-2015, 01:10 PM	#10
rmousir Private 3 Rep 65 Posts Drives: 2006 Z4 3.0si Join Date: May 2015 Location: Ohio iTrader: (0)	How would I check the RTABs to be certain?
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05-19-2015, 11:03 AM	#11
chickdr Lieutenant Colonel 140 Rep 1,989 Posts Drives: 2006 M Roadster Join Date: May 2009 Location: Buford, GA iTrader: (0)	Also check the black strut bars under the hood. Typically this popping sound emanates from the center of the dash, but it wouldn't hurt to make sure the bolts/nuts are snug.
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06-24-2015, 10:51 PM	#14
rmousir Private 3 Rep 65 Posts Drives: 2006 Z4 3.0si Join Date: May 2015 Location: Ohio iTrader: (0)	Hi guys. I've been out of town for a while but I'm back and took my car to work today and the noise is still there and it sounds like both sides. I suspect a bush or a pair of bushings. I've done my reading and I think I know what to check. I plan on putting the car up tomorrow and I hope I can find the cause. If I am correct, I will be replacing bushings, I just don't know which yet. Does anyone have a suggestion on the proper tool to use for that? Anything I should check beside bushings while I have the car up? Thanks.
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06-25-2015, 01:05 PM	#15
StickMon My other car is on Mars 636 Rep 3,124 Posts Drives: 2006 MR Join Date: Feb 2011 Location: Lo-Cal iTrader: (1)	Tools I just picked this up second hand from another forumite. There's also this, but it looks a little cheesy. __________________ Warning: May contain traces of nuts.
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06-25-2015, 05:03 PM	#16
rmousir Private 3 Rep 65 Posts Drives: 2006 Z4 3.0si Join Date: May 2015 Location: Ohio iTrader: (0)	I think I found it OK.. Got the back of the car up. I think I found the problem. Everything looks tight except for the lower bushings on both sides on the rear assemblies. Not sure what the proper name is for these but if I use my pry bar on the lower control arm that connects to the rear spindles you can see the bushings are pretty cracked up and I'm pretty sure it shouldn't be and I believe this will cause my noise when I'm tossing my car around. I've attached the picture. So my questions are: 1. Am I correct, these bushings look bad? Both sides look like this. 2. How hard is this to change? 3. Is this called the rear lower control arm bushing? 4. I suspect I will need a bushing press tool. What do you recommend? Thanks very much for any and all suggestions and comments. Richard Attached Images
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