528iAT Front End Clunk, not resolved with lots of new suspension components

[TexasTouring]

Hi all,

Here's the situation in brief: I have had an annoying front end clunk since I bought my E39. Has not been resolved even after loads of new suspension components have gone in.

The car: 1999 528iA Touring. Bought last year with 175k miles. Now at 200k miles. Non-sport suspension. Non-self-leveling suspension. Good car.

The clunk: I can hear it from both sides of the front end, and I can feel it through the pedals, floorboards by my feet, and a little through the steering wheel. It clunks over all bumps, and is especially noticeable at low speeds (but still definitely clunking at high speed too). Speed bumps and entering and exiting driveways make it clunk every time. Sounds like something is loose that shouldn't be. Not correlated at all with steering wheel position. Pushing down hard on the front end with the car parked does not replicate the clunk. The clunk is noticeable equally with and without the brakes applied.

I have replaced a ton of suspension parts over the course of fixing this car up. At the front end: new Sachs struts + strut mounts. Upper and lower control arms. Left and right Swaybar Links. Left and Right Tie Rods. 4 New tires. New brake pads and rotors. The rear suspension is all new too, including subframe bushings. Transmission and diff mounts are new, as is the giubo.

At this point, I would have expected this clunk to have gone away. Most of the suspension was original to the car, and it rides SO much better than when I bought it, but this clunk is a bad one, and it's starting to drive me a little crazy.

I plan on taking it back to the great tech at the local BMW dealer (who installed most of the above, and has lots of experience on E39s). He thinks the steering rack could be the culprit, but please post any other ideas you have!

Thanks!

[Chedley]

Check your brake calipers ? I bet they never been serviced or replaced. Heck, check and service the whole braking system.
A bad or stuck brake caliper piston can make this rattling noise over bumps, or when braking/entering a driveway.

[amancuso]

Does it feel like it's coming from the driveshaft tunnel? Could be center bearing or driveshaft.

[jclausen]

Check subframe bolts and shock mount nuts, long shot, worn engine mounts

[effduration]

Stop throwing parts at it.

find a tech with a "Chassis Ears" or buy one yourself off amazon and then rent it out or re-sell it on ebay.

search:

STEELMAN 06600 ChassisEAR on Amazon

[crazy4trains]

Does it go away when you lightly apply the brakes?

The washer placement on the sway bar end links is wonky. Make sure those are on correctly.

[BMW4RE]

My '99 528i used to vibrate/rumble when it was idling. Once I got going it smoothed out. I kept thinking harmonic balancer, torque-converter issue,, etc. I didn't notice the engine not being level, but it mustn't have been. When I finally go under to look at the motor mounts (which I had replaced some years ago), I couldn't believe what I was seeing. The cast bracket that the mount sat on had broken off, and the passenger side of the engine was pretty much sitting on a hard steering line. The bottom line is that strange things can happen to the motor-mounts and bracket that might cause clunking as the engine bounced. So whoever mentioned the motor mounts may be onto something. Good luck.
BimmBreak.jpg

[spkrboxx]

I have been chasing something similar on my 2001 540it. I have done all of the arms, shocks, spring isolators, strut mounts, sway bar endlinks. Still there. I have new OE sway bar bushings and engine mounts showing up on monday. Hope it fixes it.

[TexasTouring]

Thank you all for the advice. The VANOS went in late June, and I just got around to rebuilding it last week, so I hadn't been driving the 528. Now it's back, and the dealer tech confirmed the Rack and Pinion needs to be replaced. I'll do engine mounts and sway bar bushings at the same time, but is there a "best" place to source a steering rack?

Looks like a rebuilt OE rack is pushing $1k on FCP, a used rack is about $100, and various rebuilt racks are between $250 and $500. I found "Rack Doctor" at the low end of that range, and am thinking about going that route. Anyone have any advice?

Thanks!

[TexasTouring]

Just to close the loop on this, it was the front sway bar bushings.

Ended up doing engine mounts and a steering rack too, the old ones were truly shot.

Drives much better now, still not as good as my lower mileage e39s, but getting there!

[ross1]

" plan on taking it back to the great tech at the local BMW dealer (who installed most of the above, and has lots of experience on E39s). He thinks the steering rack could be the culprit, but please post any other ideas you have!"

Sway bar bushings! ? That's pretty easy to spot.
Seems this great "tech" with vast E39 experience is blind but well funded.

Has anyone else noticed that mechanics who think of themselves as "technicians" often can't diagnose worth a sheet? Apparently no button on that zillion dollar BMW diagnostic machine that reads "check the obvious".
Snotty, you're up.
Sorry for your pain, OP.

[JimLev]

That great tech must have had a boat payment due.

[TexasTouring]

Ha! He's a good guy, but I'll use it as an opportunity to survey the local service landscape... see who else is out there. In the past, the independent specialists in my area have been much more expensive than the dealer, so we'll see.