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-   -   (Klunking diagnostics) Coils? Struts? Can push the wheel up when it's on a lift? (http://www.bimmerfest.com/forums/showthread.php?t=653066)

EconoBox 10-20-2012 03:41 PM

(Klunking diagnostics) Coils? Struts? Can push the wheel up when it's on a lift?
 
I've been getting a klunking sound when driving over small bumps. I took it to a local indy to have him take a look. He put it up on the lift, and used a long pry bar to see what arms had play. None had any obvious play.

I told him the upper control arm (thrust arm) bushing is known to fail. This is the one with the large plastic shield around it. Nothing was obvious there either. I told him they are oil filled, but there was no visibile leak on either, and no hint of oil on the plastic shield.

He then pushed the entire wheel up with his shoulder, like he was pushing a tackling dummy. Here is the weird part: The passenger side went up fairly easily. He could lift the entire wheel several inches. However, the driver's side wheel would not budge. He was unsure what the correct behavior is, b/c he's not a BMW specialist. He suggested that one of the struts might be bad, but was unsure which one. Anyone know which side is faulty?

Also, when the car was on the ground, he was able to push down on both corners of the hood, so neither wheel appears "stuck" from that perspective.

Ok, so you should NOT be able to lift the wheel that much? That's the bad side? Either it's a bad coil spring and/or a bad strut. But, would this explain the "klunking" I'm getting over small bumps?

Just wondering, do coil springs go bad very often? Will you see a visible crack in the coil, or did it just loses tension/spring and is "dead"?
I think I will just replace both coils and both struts... since they are all original with 130k.

Anyone know a part number for the coil for a 530i with M-suspension?

Using my website, www.furiousmethod.com and part number 31311096857
it looks like each strut will run about $110.

Approx. what would an indy shop bill for doing both sides of front coils/struts?

Fudman 10-20-2012 03:50 PM

The first place I'd look for clunking in the front end is the sway bar links. This is very common. Next is the strut itself. Do a search for clunking for more info.

bluebee 10-20-2012 05:09 PM

Quote:

Originally Posted by EconoBox (Post 7147319)
would this explain the "klunking" I'm getting over small bumps?

Is this klunking the same as experienced by many of us documented here?
- How to diagnose severe ABS shuddering while slow speed braking on bumps (1)


If not, if the bestlinks are any good, your klunking 'should' be in this list somewhere:
- The main causes of vibration while highway driving (0) (1) (2) (3) (4) (5) & while highway braking (1) (2) (3) & why it's not rotor "warp" (1) & severe ABS shuddering while slow speed braking on bumps (1) & how fluid-filled thrust arm bushings crack and tear causing the BMW to vibrate at speed (0) (1) (1) (2) (3) (4) (5) (6) (7) (8) & a comprehensive TireRack vehicle vibration diagnosis chart (1) (jpg) with wheel match mounting hints (1) & how a worn drive shaft, flex disc, center bearing, or "giunti Boschi", aka giubo (it's not spelled guibo although it sounds like it is to some) can cause the vehicle to vibrate (1) (2) (3) (4) & how to repair the rear driveshaft seal by the differential (1) & how to repair the inner constant velocity (CV) half-drive shaft (1).

avu3 10-21-2012 09:20 AM

I'm concerned there's something here I'm missing.

The Indy should have been able to tell you that a bit of lift is normal. Normal suspensions "droop" when on a lift and should have some play in them before you start compressing the coil (which he wouldn't be able to do tackling-dummy style). That he didn't or wouldn't tell you this bugs me. He's either inexperienced, disinterested in working on the car or scared of it.

Coils rarely fail catastrophically, at most they lose a bit of spring... but that loss probably isn't a big deal for a street car. Unless the extra money isn't important to you or you need to pay for them for piece of mind, I wouldn't replace them. When they fail catastrophically you hear scraping and see it broken and that corner of the car is lower. You'd notice this, I believe.

Struts, you always replace in pairs, so doesn't matter if the hard to push or easy to push one is at fault, you're replacing both of them.

I'm going through the same as you. My car had a clunk that could not be found. I took it to a BMW Indy and my struts are so bad that when you compress them, they "catch" and will hold the assembly up against gravity. The inside of the struts have hard parts catching on each other, there is no more hydraulic action.

You're going to be hit with 2-3 hours labor PLUS you'll need an alignment when they're done.

S

EconoBox 10-21-2012 12:11 PM

But, again, how do I even know it's the strut that's causing the clunking?

Regardless, it seems like a strut job is a $1000 job.
$300 for labor, $600 for parts.....RealOEM lists them for $300+/ea.

You can buy them online for $110/ea, if your mechanic allows you to supply parts.
That would bring it down to about a $500/job.

Is a strut replacement a major job best done by a specialist?
Or can I take my E39 to any old mechanic, b/c they all know how to do a strut job.
Is this even remotely possible for a home DIY if you're not a DIY guru expert?

vavet5308 10-21-2012 04:36 PM

You can certainly take it on as a DIY, but it's probably best only done partially. Removing the strut/spring assembly is pretty straight forward if you have tools and a place to work. Installing the new strut is DANGEROUS if you don't know what you're doing. Professional shops have a wall-mounted spring compressor so the whole assembly can be installed in the compressor, the spring is partially compressed and held, and then the strut can be removed. http://www.autobarn.net/xxxw-bra7400.html

If you take off the nuts from the top of the strut which held compress the spring, the spring is coming out doesn't care who or what is in its way. It is possible to buy a spring compressor that goes on the outside of the springs and I've used them, but they're a little scary.

Fudman 10-21-2012 07:04 PM

Quote:

Originally Posted by EconoBox (Post 7148586)
But, again, how do I even know it's the strut that's causing the clunking?

Regardless, it seems like a strut job is a $1000 job.
$300 for labor, $600 for parts.....RealOEM lists them for $300+/ea.

You can buy them online for $110/ea, if your mechanic allows you to supply parts.
That would bring it down to about a $500/job.

Is a strut replacement a major job best done by a specialist?
Or can I take my E39 to any old mechanic, b/c they all know how to do a strut job.
Is this even remotely possible for a home DIY if you're not a DIY guru expert?

Yes, front strut replacement is a doable DIY. I would rate it a 7 out of 10 for difficulty, with a CCV job an 8 and a Vanos job a 6. A 6 to 8 hour job. Strut compressors are available on loan from the auto parts store. An impact wrench makes life a bit easier.
While you're at it, replace your thrust arms, control arms, tie rods and sway bar links. Parts will cost $1,200 but your car will ride and handle like near new. Just follow the Beisan DIY and cn90's DIY.

16valex 10-22-2012 06:37 AM

Replacing strut is not for the light hearted noobies. Try to clear the wheel well is a PITA, I hate this part of the whole R/R. :rofl::rofl:

timarnold 10-22-2012 08:46 AM

I had a very similar experience last week. I had been hearing the clunk for about a month & was finally able to duplicate it by putting the car up on jack stands & then jacking the tire up with the jack. While the passenger side worked smoothly, the driver side would catch & then clunk when released. I haven't had time to take the strut apart to see exactly what is going on.

EconoBox 10-23-2012 05:55 AM

Quote:

Originally Posted by 16valex (Post 7149900)
Replacing strut is not for the light hearted noobies. Try to clear the wheel well is a PITA, I hate this part of the whole R/R. :rofl::rofl:

Say no more. It took me 5 hours to replace a fuel filter. That was a nightmare. This is a job for a pro, not me.

doru 10-23-2012 07:57 AM

Quote:

Originally Posted by 16valex (Post 7149900)
Replacing strut is not for the light hearted noobies. Try to clear the wheel well is a PITA, I hate this part of the whole R/R. :rofl::rofl:

He has the sport suspension setup, which will clear the wheel well much easier (the strut is smaller in length) - I know what you're talikng about. Been there.

Quote:

Originally Posted by EconoBox (Post 7152035)
Say no more. It took me 5 hours to replace a fuel filter. That was a nightmare. This is a job for a pro, not me.

That is an easy job - the fuel filter that is. You probably tried to pull on those old rubber hoses instaed of just cutting them with an exacto and replacing them.

If you do the suspension work, don't skimp on the hardware for the struts/shocks. The upper bearing mounts will fail, especially if the strut/shock is blown - there's more strain on them. Also, do yourself a favour and check the strut tower inside the engine bay. If you see any signs of mushrooming - your struts are almost 100% blown, because they bottomed out and started to deform the strut tower. There are reinforcement kits for that, and I kick myself for not installing those when I replaced my suspension (I didn't know about these at that time).

crazy4trains 10-23-2012 08:39 AM

Another potential source of "klunking" is loose inboard brake pads. I had an annoying klunk from the rear driver side area that I could not pin down. I rotated my tires last weekend and removed the caliper. When I removed the caliper the inboard pad fell out. It should not do that!!! I pried apart the retainer clips on the back of the pad and replaced it in the caliper. Klunk is now gone!

If you can't get a positively identified defect on one of your suspension components checking the inboard brake pad is worth the effort. If that is your problem you will have invested about one hour and zero $$$.

EconoBox 10-24-2012 06:04 PM

Quote:

Originally Posted by doru (Post 7152322)
If you do the suspension work, don't skimp on the hardware for the struts/shocks. The upper bearing mounts will fail, especially if the strut/shock is blown - there's more strain on them. Also, do yourself a favour and check the strut tower inside the engine bay. If you see any signs of mushrooming - your struts are almost 100% blown, because they bottomed out and started to deform the strut tower. There are reinforcement kits for that, and I kick myself for not installing those when I replaced my suspension (I didn't know about these at that time).

Can someone help me out with part numbers for:
1) hardware for the struts/shocks
2) Strut tower reinforcement kits

doru 10-25-2012 07:42 AM

Quote:

Originally Posted by EconoBox (Post 7155934)
Can someone help me out with part numbers for:
1) hardware for the struts/shocks
2) Strut tower reinforcement kits


1.) Realoem is your best friend. Front struts hardware, rear shocks hardware
2.) Reinforcement kits - you need to search for them. They're not OEM. Here are some:
Bavarian Motor Parts
Beastpower
Or you can use a strut bar, which has the reinforcement plate on it:
Harrisonmotorsport
Turner Motorsport etc

P.S.: for the hardware, you can contact Jared @ EAC and he will help you out.

Bimmer Bob 10-25-2012 11:50 AM

Can I suggest strut top mounts?

Done them on my 525 Touring and just about to do them on my 535 V8.

If you clamp the coil springs up with compressors, then spin the top nut off with an impact wrench. Undo the 3 retaining bolts and free the assembly. You can just about get enough clearance to get the new top mount in there with a bit of wangling.

An hour a side?

EconoBox 10-27-2012 04:49 PM

Update: I took it to a double indy. Former BMW tech who works out of his house.

He pushed down on the corner of the hood and instantly concluded "bad shocks". It's pretty easy to push the car down. On mine, you could sustain a bounce by repeatedly pushing down. All 4 shocks are gone. He had me push his BMW's hood, and you could barely push it down. No chance you can start "bouncing" it with ...umm...rhythmic thrusting. We looked at the shock and saw the bellows part was torn on both. He said the coil spring is fine ("they don't go bad") He said when struts are bad, they make the clunking sound.

He then got under the car and took channel lock pliers and twisted the control arms. He said there should be no play. He said I need front and rear control arms. He also says he just replaces the stabilizer links as well (that vertical rod/ball joint that's positioned higher up on the wheel) I'm not sure if I REALLY need them, or if he's being a purist. Incidentally, both my left front and rear control arms were replaced ~ 4 years & 40-50k miles ago.

For now, I might do just the struts and see the result. Since they control arms are a separate job anyway, I am in no rush to do these, especially if the clunking is resolved by the struts job. Particularly b/c mechanic #1 didn't seem to think they were an issue and were tight enough. I think if they're REALLY bad, they're much looser than mine.

I will update this thread once there is action taken..

EconoBox 10-27-2012 04:54 PM

Doru, I will order the $60 reinforcement plate. Why not.

Also, great call on replacing worn hardware while doing the strut.
But, which item numbers (#1-13) in the realOEM diagram would you replace?
http://realoem.com/bmw/diagrams/l/f/17.png

Fudman 10-27-2012 06:35 PM

Replace the #1 strut mount (guide support). The rest of the stuff can be reused.

EconoBox 10-27-2012 08:07 PM

Thanks, Fud.

I was also told #11 and #12 should be replaced.
So, I will def. order 11 & 12. Mine are currently torn.

Maybe I will order #1 just in case, and if my originals are fine, I will just return them?

Why does one need to replace #1?
#1 seems like "forum overkill" that is probably unnecessary.
I mean, are my strut mounts possibly defective if my towers aren't bent?
Are they even a wear item, or just a hunk of metal? Do they go bad eventually?

Fudman 10-28-2012 08:01 PM

The strut mount is "just not a hunk of metal". The have a rubber insert (like a bushing) that helps to attenuate the impact of the top of the strut against the car. Do you have to replace it? Not necessarily. But are you willing to take the chance that your 100+K mile car has not worn out the strut mount? Given the $37 cost vs. paying an indy to do ithe job ($200-$300) again, I'd spend the money. I DIY and spent the money because i didn't want to chance having to redo the job. My advice is don't half a$$ a repair to save a few bucks. These are not Toyotas.

EconoBox 10-28-2012 09:13 PM

I agree. If there is bearing and rubber, I will replace it.
Is Lemforder ($30) an acceptable replacement, or should I stick with Sachs? ($38)

Fudman 10-29-2012 04:53 AM

I went with Sachs simply because I went with Sachs struts.

EconoBox 11-15-2012 06:31 PM

UPDATE: $110 Sachs red label "Advantage" struts.
The strut/end link combo definitely solved the issue.
The clunking at low speeds is gone.

I ordered all the parts from AutoHauz for about $410 total. (BMA for the Lemforder sway bar end links)
(struts, strut mounts, boots, stoppers, upper/lower rubber spring pads, sway bar end links)
Got them all installed by an indy for $300. Total about $700 for everything.

Both original 130k mile struts were blown. You could pull the piston in and out easily with your hands.
The driver's side even had a leak, and therefore was caked in dirt.
While installing, they seemed to have an issue with the red label being a slightly different length of piston arm (shorter)
They had to compress the spring a little more than normal to get the bolt on. (3 rungs instead of 2)
But, in the end, they got the coil back on, and all seemed the same length as the OE strut.
I also reminded them to seat the coil before the "dip/lip" in the housing, as indicated in one of these threads.

FYI, they said they never replace the strut mounts, and they just repack some grease into them.
(Mount bearings don't really spin at rpm like a belt pulley or wheel hub bearing)
But, one of my mounts' bearing was a little "rough" b/c the protective cap was missing.
So, I replaced both strut mounts, since I had ordered them anyway.

I have the M-suspension, based on the online VIN checking "build sheet".
The Sachs red label Advantage looked identical to the OE struts that were removed.
However, the part numbers did not appear to match. (But, the website did say "upgraded OE version")
Sachs-Boge OEM Strut Assembly; Front Left/Right; Advantage/Upgraded OE Version
For sedan models with M-Technic Sport suspension. 2 per car. Limited Lifetime Warranty. Limited Lifetime Warranty.

The part number labelled on my original OE Sachs strut was: 82 4904 557 210 (or 824904557210)
The part number on my aftermarket red label Sachs "Advantage" strut was: 82 4904 556 834 (or 824904556834)
RealOEM indicated my part number was: 31311096857, and this is what linked me to the red label Sachs above.
http://i50.tinypic.com/24wsjuc.jpg http://i47.tinypic.com/2ytqhrk.jpg

The clunking at low speeds is gone. The strut/end link combo definitely solved the issue.
I will update this thread if I have any problems with the $110 red label Sachs struts.

Jason5driver 11-15-2012 09:57 PM

Excellent...!
How is the ride...?

Thanks!
Jason

EconoBox 11-17-2012 04:27 PM

It's just fine.
I'm not a racecar driver, so no clunking is all the improvement I need!
Any nuance beyond that is pure placebo effect, as far as I'm concerned.


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