annoying tapping sound update

[BMW4ever]

recap: i asked how to remove the back rest to find the annoying tapping sound (while driving) from the rear panel that is gettin' worse.

525SEI BRIT responded with possible causes, and bill g sent links with pictures how to remove the back rest. thank you guys. saved me tons of time.

now, i managed to removed the back rest, and still couldn't figure out what is that tapping sound; however, i locked in the source (it's in the left rear with metal to metal hitting each other sound). took it to my mechanic today, and he showed me there is a hairline crack :( in the body (rear-left next to the shock). this is my first encounter with hairline crack in the body of the car.

my mechanic applied some wd-40 on the hairline crack. annoying tapping sound is gone! he said that the possible cause of the hairline crack was due to my aftermarket wheels (20 x 8.5 all corners). i'll be back on his repair shop to monday to get the hairline crack welded before it gets worse per my mechanic's advice.

are bmw e34s prone of hairline cracking of the body? especially near the shocks. anyone have similar experiences?

[Russell]

IMO, 20 inch wheels are way out of spec for this car. I suspect they put a great deal of stress on all of your suspension as well suspension to body mounts. I would fix the crack, inspect the other side for damage. Not sure how the front is impacted. Long term, put smaller wheels on the car.

[632 Regal]

I'm just wondering when they will come up with solid rubber tires so we can run 24's.

[Denton]

Need pics of said vehicle, on said 20s.

[632 Regal]

+ girlfriend
Need pics of said vehicle, on said 20s.

[wjbell]

are bmw e34s prone of hairline cracking of the body? especially near the shocks.

Only when you put 20" wheels on a car designed for 15's. ;)

[BMW4ever]

in response to denton. i don't have camera, and card reader; but, the wheels are Beyern Wheels. Style: Mesh. i used to have 18 x 8s, but the "my wheels are getting small" bug bit me. so i switched to 20inchers. i will try to barrow my neighbor's camera and get some pics.

[Denton]

in response to denton. i don't have camera, and card reader; but, the wheels are Beyern Wheels. Style: Mesh. i used to have 18 x 8s, but the "my wheels are getting small" bug bit me. so i switched to 20inchers. i will try to barrow my neighbor's camera and get some pics.

I swear to God I'm absolutely curious as to how they look. Expecting the worst but hey, I've only got lowly 17s.

[BMW4ever]

don't worry. it's not one of those "dub" wheels, spinners, the one you see on suv's, or bling-bling type of wheels you see on "pimp my ride." i carefully selected these wheels (took me two months to shop and research) as to make sure the "import crowd" and "rice rockets" cannot get these wheels on their cars. well, they can, with wheel adapters if they are really that desperate. in addition, i made sure the design is close to bmw's design as possible. kinda like classic design--not trendy or fad.

[wjbell]

Like these? ... Sorry, couldn't resist.

http://www.belletc.net/bmw/E34Blingmobile.jpg

[BMW4ever]

[Like these? ... Sorry, couldn't resist.]

not even close ;-)

[stargazer_61]

I had this same problem, on the same strut tower, however I only have 17" style 5's on mine, so I don't know about your mechanic's diagnosis being 20" wheels being the cause. It was really annoying and very hard to find where it was coming from. But it's been fixed for a couple of years now.

[BMW4ever]

hi stargazer 61,

nice to hear from fellow e34 enthusiast with the same experience. i remember now how the hairline crack developed. after i hit the steel plates (Caltrans put them on the road to cover unfiished road repair) when passing road construction zone on freeway ramp. they did put a "warning steel plates ahead" sign, but not early enough. by the time i saw the sign partially hidden, it's too late to slow down/brake. with 235/35/20 tires setup, it was darn harsh. after couple of weeks, the tapping sound developed. i'm sure this was the major contributing factor.

my mechanic is right (it's the fact) one thing though. my car is engineered for 15inchers, so havin' a 20inchers setup will mess up the whole geometry of the suspension.

i'm glad you fixed yours. i have to fix mine on monday. i diagnose mine with trial and error. i had to remove the back seat and back rest in order to pinpoint the location of the annoying sound.

cheers.

[stargazer_61]

Yeah, I diagnosed mine by trial and error as well. I ended up stripping the entire trunk & back seat areas, then climbed in the back while my daughter drove me around, hanging on for dear life (teenage drivers, ugh!). Anyway, I don't know how it ended up cracking. I don't remember running over any large bumps, but it could have been. 15" wheels would have absorbed much more than the 17's do.

I may get flames for this, but I ended up fixing mine by cutting up one of those thick felt "super chamois" cloths and stuffing it around the crack, then sealing it in with JB Weld. This has held for two years now.

Between repairing that rattle, the door seals and sunroof, it is nice and quiet in the cabin now.

Good luck getting yours fixed. If you have the repair professionally done, would you mind sharing how much you were charged?

John

[525SEI BRIT]

Glad you uncovered the problem. But we gota see some pics of that crack and the 20 inches of cause!!

[bmwrp8]

Yup i'm curious aswell show us the hairline crack and those 20"

[bissellh]

I had the same problem in my 1992 BMW 525i E34 M50 after I installed Eibac lowering springs with Bilstein Sport shocks and stuts. I was running 17" wheels. The Sports were way too stiff. When I hit a pot hole, it felt like the car was going to break in half and my dental work was going to fall out. My resolution was to replace the sports with touring class shocks/struts, keep the Eibach lowering springs and weld the hairline crack behind the rear seat back rest.

The ride with the touring class bilsteins and lowering spings is very smooth plus I get better handling with the more aggressive stance. I am not having any problems with pot holes or the body of my car cracking. I would highly recommend this setup to anyone who wants to improve the handling of their E34 without sacrificing comfort.

I later learned that bump stops in the sports in combination with the lowering springs may have been bottoming out causing the rough ride. I read somewhere that a resolution is to open up the sports and cut down the height of the bump stops. I never had a chance to try it though.


recap: i asked how to remove the back rest to find the annoying tapping sound (while driving) from the rear panel that is gettin' worse.

525SEI BRIT responded with possible causes, and bill g sent links with pictures how to remove the back rest. thank you guys. saved me tons of time.

now, i managed to removed the back rest, and still couldn't figure out what is that tapping sound; however, i locked in the source (it's in the left rear with metal to metal hitting each other sound). took it to my mechanic today, and he showed me there is a hairline crack :( in the body (rear-left next to the shock). this is my first encounter with hairline crack in the body of the car.

my mechanic applied some wd-40 on the hairline crack. annoying tapping sound is gone! he said that the possible cause of the hairline crack was due to my aftermarket wheels (20 x 8.5 all corners). i'll be back on his repair shop to monday to get the hairline crack welded before it gets worse per my mechanic's advice.

are bmw e34s prone of hairline cracking of the body? especially near the shocks. anyone have similar experiences?