Roundel - July 2005

Review of BMW 5 Series Service Manual: 1997-2002 and BMW Z3 Service Manual: 1996-2002 from Roundel - July 2005

by Mike Miller

"For the many do-it-yourselfers in the BMW world as well as independent BMW shops, the quest for BMW service information is like something out of Indiana Jones and the Last Crusade: a quest for the Holy Grail. This is because BMW, unlike any other car manufacturer we know of, is incredibly secretive about service information. The company considers it "proprietary information" and shares it only within the corporate family?along with independent BMW shops in the U.S. who pay a substantial fee for access to a secret web site and the BMW GT-1 computer.

It wasn't always this way: paper versions of BMW factory service manuals used to be available for purchase through any BMW dealership. But those days are long gone, except for older models. (BMW Mobile Tradition sells service-manual CDs for many vintage Bimmers. E-mail techtalk@roundel.org for a list of part numbers.)

For the rest of us, there's a very small number of independent service manuals available. Bentley"s technicians and technical writers buy subject vehicles and literally disassemble most of the cars to write and photograph their manuals. Like every service manual?including the factory ones?the Bentley manuals are not perfect. No one can foresee the service issues a given car will have as it matures. But Bentley service manuals are, in my opinion, the best you can buy. And that margin of superiority is very wide.

The two latest editions to Bentley's BMW service manual collection arc a revised edition of the original BMW Z3 Service Manual, the revision covering all model years from 1996 through 2002, including the Z3 Coupe, the M Coupe, and the M roadster; and the BMW 5 Series Service Manual, 1997-2002, covering all E39 5 Series cars including sport wagons?but not including the M5.

Bentley manuals contain comprehensive wiring diagrams and on-board diagnostic sections, including the elusive OBD-II P-codes. The E39 5 Series manual is actually a two-volume set; the second volume is dedicated entirely to the complex electrical and electronic systems of these cars. Professional shops will find that the Bentley manual is the next best thing to an expensive BMW Technical Information System subscription, and will often augment it. After all, it's hard to put a laptop on top of the engine or hold one upside down while you"re under the dashboard.

All is not rosy with Bentley manuals, though, and it goes back to those service issues that cars develop as they mature. For example, the Z3 manual does not show us how to replace the plastic rear window; there is a zipper, but it is covered by PVC piping trim. Nor does it deal with preventive or rehabilitative measures for plastic-rear-window maintenance. Nor are aftermarket solutions to common problems covered by the manual. Z3s often suffer from a loose seat problem, which is fixed by some very simple aftermarket parts same with a squeaky clutch pedal.

The E39 5 Series Manual suffers from similar small omissions. For example, as the V8 engines mature, cooling-system problems, gasket failures, and oil-separator failures are common. It would be nice to have a section detailing diagnosis and repair of these problems.

Finally, one can see that Bentley Publishing is sometimes constrained to genuflect toward BMW headquarters. "Lifetime fill" lubricants are tacitly mentioned in the manuals, as well as frequent admonishments that "special BMW tools are required," although that last is legitimate and universally accepted service advice. The absence of any reference to aftermarket solutions to common problems also probably falls under the genuflecting exception.

Overall, though, you cannot buy a better service manual than a Bentley hook. The body of work involved in even a simple service manual is overwhelming, and nothing is simple about modern BMWs. I have a full set of these manuals next to my desk; as the grease stains testify, they are also used in my own do-it-yourself garage."