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Friday, April 25, 2014

Doug's Domain

Doug Vetter, ATP/CFI

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October 1998

Front wheel shimmy

Apparently, some 328 sport package cars have a problem with front-wheel shimmy due to harmonics that feedback through the steering wheel when the car is driven for the first few miles on a cool morning (35-45 degrees) between 1800-2200 RPM, courtesy of an improperly engineered power-steering pump system. I test drove the car with a dealership rep, and then a BMW rep, but as the weather on each morning was unseasonably warm and I had driven the car for over 10 miles just to get to the dealership where the tests were performed, I was unable to duplicate the problem with them. Therefore, they pledged to do nothing about it until, when or if, I could demonstrate the malady.

The first time I went to the dealer, the shop DID find one of the front wheels slightly out of balance. The tech rebalanced the car and test drove it without me (I'm a working stiff, so I had to leave the car with them--fortunately I was given a nice 528 loaner to "test drive"). He said he couldn't duplicate the problem. When I accepted the car at the end of the day, I drove it home with no indication of the problem. The next morning was cold, and sure enough, when rounding the first turn on the road out of my driveway at about 50 MPH, turning the wheel as necessary produced the feedback.

I called the dealer, let them know about the problem, and demanded a BMW NA rep come in to check the car out. Unfortunately, the problem never materialized during that 10 mile test drive, but the rep and dealership got to business, researched the problem for me and found a potential solution -- a known fix that would require the addition of rubber isolation mounts to the pump. The car was again scheduled to have this fix performed and I got the 528 loaner. Following the fix and a few days of driving, I found the symptoms of the problem not as prominant, but still noticable. Sadly, I attributed this more to the fact that the average morning temperature had climbed considerably -- it was, after all, now spring -- rather than the fix itself.

Of course, I couldn't quite understand BMWs logic in this entire affair. Rubber isolation mounts sounded like a band-aid fix (a HACK in software development terms) for the problem. Why put isolation mounts on a shaking pump? Why not just redesign/replace the pump, the length or I.D. of the lines feeding the steering system, etc., to rid the system of the standing waves that form and cause the shaking? Well, as it turns out, this is a fairly common problem, but not everyone complains about it (so I'm an anal-rententive engineer!...what's your point?). That puts it into the BMW maintenance category of "Well, we'll lose our shirts redesigning the <fill in the blank> for these customers, so let's not and hope we don't make the papers on this one".

Thus I learned what BMW does well in the maintenance department and what it does not. This is not to say that the cars are poorly built -- on the contrary -- the fit and finish of a BMW is difficult for the competition to duplicate and it's safe to say a BMW rarely requires unscheduled maintenance in the first few years. However, if you have a manufacturing defect that can be repaired or replaced fairly easily in the field, BMW will fix it for free (under warranty, that is) and not give it a second thought. On the other hand, if you have either a VERY common "nuisance" problem (that does not affect the safety or basic "driveability" of the vehicle), or a problem that would require a substantial investment in engineering--especially near the end of the model's life-span, BMW will NOT be very helpful.

The bottom line? Since I believed this to be temperature related, the dealer rep told me to bring the car back this winter for another test drive. Of course, one of the biggest problems of owning a BMW is that once you take possession, you'll never want to give it up--ever--even for needed maintenance.

First oil service:

Did you know that BMW programs the computer to trip the "oil service"lights at between 8-10K miles? Yea, that's what *I* said(!) Well, the reality of BMW's "free-maintenance program" is that BMW is doing what BMW needs to do to remain profitable. No car, especially a BMW, should go that long between oil changes, but BMW does it because $50 every 10K miles is better (for them) than $100 every 10K miles. This newsflash comes straight from a rather down-to-earth, "seasoned", BMW tech. Put another way, if your engine wears out at 200K miles instead of 300K, well, that's great, again, for BMW, because it will bring you back to the dealer (presumably for a new car) sooner while you continue to tell all of your friends that the car lasted "that long". I was disturbed when I first heard this because this didn't sound like a standard BMW policy, but simple math and a P&L statement tell the true story of BMW's scheduled maintenance program (or, likely that of other car manufacturers, foreign and domestic). Hence, Caveat Emptor.

Bottom line? Depending on how you drive, if you follow BMW's scheduled maintenance program, you'll likely reach the first oil change at about 9K miles, give or take. I would strongly recommend that all new owners schedule their first oil change at no later than 4500 miles and make sure whoever does the oil change DOES NOT reset the maintenance interval lights. If you have this done at the dealer, you'll pay for this first oil change because it's earlier than the schedule prescribes, but so long as you DO NOT reset the maintenance interval lights the first time, when the first "scheduled" oil change interval arrives at 9-10K miles, you WILL get that service for free. This surely applies to other inspections as well. Try to think of BMW's scheduled maintenance NOT as "free maintenance", but DISCOUNTED maintenance -- given the oil service example, this means you'll really pay $25 per oil service -- about industry standard for more "common" vehicles.

FYI, most dealers will also clean your car, inside and out, when it's in for an oil service. If yours doesn't (or if you're like me and you don't want ANYONE touching your car because it's always clean, thank you very much), be sure to let your tech know what you want before you hand over the keys.