Steering wheel vibration and brake fluid smell.

[Bmwtvboy]

This doesn't happen all the time and since putting the x back on the road after sitting 6 months I have noticed it twice over the past 8 weeks. First my brake pedal effort is normal, not soft or hard. The car brakes without locking up or shuttering or pulling. HOWEVER, the other day the car was bouncing down the road in "drive mode" at 45mph and after braking a few times I smelled brake fluid. I didn't see any drips or leaks on the drive or by the wheels in front or rear. Two days later I take the car to the shop and it drives perfectly. No issue but there was a very, very slight brake fluid smell. The shop has the car two days and said it drives fine no issues. Secondly, there is a vibration in the steering wheel when the car is idle after warming up and sitting at a light. It is very noticeable. When I drive from stop to 55 there is no vibration in the wheel until I stop again. Can these two be related? Bouncing front end, steering wheel vibration?
How do you know when your motor mounts are bad and will they effect steering wheel vibration? This X had a complete front end rebuild, new Bil' shocks in front, all bushings, and drive shaft boot replacements. I have never had any vibration in the steering wheel, I've owned the X for 9 years. 178K . The Bilstein shocks are stiffer than the OEM, but I can't imagine they would bounce the front end while driving forward at any speed.
The last time the car was at the shop 8 weeks ago with this similar issue they explained that the bouncing effect may have been caused by the brake on the left side sticking in braking mode and when the car was on the lift sure enough the wheel was hard to turn freely, after a few forceful turns it was turned freely. They mentioned it may be the brake lines. But the problem never reappeared, it has since clocked 1500 miles, oil change and window clips and then the problem showed itself three days ago, almost 8 weeks after the first occurrence. On a very limited budget so I can't just throw parts and service at it. When do you replace brake lines? This X has had brake fluid flushes every 2 years while it was in Pacific NW. It has only been in FL for 8 months.
Thanks in advance.

[TwinTurboGTR]

It would help if we knew what kind of X5 you had. Braking system is similar, but different sub models have different identical failures.

With that said, the description is a little confusing. The brake fluid smell... Does it smell like it is burning or just as if you opened a fresh container? Brake fluid has a very faint odor. Since the X was sitting for a long period of time, it may be beneficial flush the brake system and get fresh fluid in the system, especially if its been over 2 years, but as you mentioned it has a good track record... unless you did it yourself, do it again. Also may be beneficial to remove the calipers and inspect the dust boots on all of the calipers. The wheel that was not rotating freely, it could be a sticky caliper, or could be a binding wheel bearing, or binding axle... for them to say it was a sticky caliper and not look into it further was irresponsible.

As far as the vibration in the steering wheel... it sounds like you have a bit of a rough idle going on, if I am understanding your statement right. Is the steering wheel itself only shaking or is it the whole car? Need a little bit more information on that. We know it doesnt vibrate once the car is in motion, which eliminates suspension. It could be motor mounts, but with such a heavy car, you will feel a "SLAM" when you take off from a stop.

As far as brake lines... if you are not losing a high amount of fluid or getting a spongy pedal... chances are your lines are fine. Do a visual inspection... but a busted line is very noticeable.

So get back to us with more info.

[Bmwtvboy]

Great questions. Great news my 01X5 3.0 auto/178K needed a new left caliper and brake line. It turns out the rotor was freezing up while trying to drive. The caliper had froze up as well. It rides smoothly, brakes quick and evenly and straight. No issues. BUT the vibration continues: While the X is at idle in "drive"gear but stopped it vibrates in the steering wheel and can feel it in the driver door and car seat. In braked stop mode, gear in Neutral the vibration all but disappears. In park there is vibration. No vibes when driving forward at any speed. Is this a drive train issue, torque converter?
I am baffled ..