Interesting E46 M3-related info from ROUNDEL magazine

Hey there 3-series/M3 folks:

I got my first issue of the BMW roundel magazine since I just joined BMW CCA club. They have a Tech Talk section where people send in comments/questions and the tech editors answer them. You know, like in the other car mags.

Well here are a couple that should prove interesting to you guys that caught my eye:

S54 engine redline:

"S54 is an outstanding achievement marred by TWO things: 1) The ridiculous 8000 rpm redline mandated by BMW's marketing weenies, which together with other factors such as oil temperature and 15,000-mile oil changes, led to these engines self-destructing in the E46 M3. No problem in the Mcoupe and Mroadster, because those have 7,600-rpm redlines. Last service action on the S54 included a DME reprogramming -- including a lower redline. How low? We don't know. BMW isn't talking about it. My guess is 7,900, which, apparently, is low enough. 2) 15,000-mile oil changes: Even with BMW's excellent Castrol-made TWS Motorsport 10W-60, that's simply too long. It's what causes the sludge problem."

So keep that rpm no higher than 7600 rpm and change your oil every 7500 miles and your S54 will live long and prosper.

SMG Shift-Switch Cleaning?

This one guy was saying how his UPSHIFT paddle on his 80k miles M3 SMG (2002 model) began to sometimes not work when he pulls on it. He claims it's a bit more stable in colder weather but was asking what's up with that. He said his tunnel shifter continues to work fine though. The Roundel editor told him they haven't heard of this problem before, but it's most likely just a switch contact issue. There's a switch set under the steering-wheel airbag module that is connected by a wiring harness. The shift levers actuate the switches. He probably just needs to spray the switches with electrical-contact cleaner, then reinstall. The airbag has to come out for this quick job however.

How to shift the SMG?

A 2004 SMG M3 owner wrote in asking them what's the best way to shift. Lett up on the accelerator between shifts, or no? Here's their abridged answer"

"It's quite difficult to shift smoothly in any BMW SMG except for hard acceleration in S4 and S5. I don't see what harm throttle lift can possibly cause. I agree that SMG power shifts seem to e very hard on the drivetrain, the differential in particular. And they're also hard on the rear tow bushings. Regarding the former, the M variable-lock differential is a masterpiece and appears to be quite strong. Moreover, M-cars have the benefits of a 1200-mile break-in service and gearbox and diff oil changes every inspection II (every ~60k miles) -- maintenance BMW refuses to authorize on non-M cars, to their eventual detriment. Regarding the latter, M3 drivers operating con brio are now accustomed to replacing the toe bushings every 10-20k miles. Normal street use, figure every 40-50k. There are permanent aftermarket solutions, but you have the choice between paying $700 for a set of quiet and durable Dinan toe bushings, or far less for a set of noisy and durable toe bushings from a number of other sources."

Fun fact mentioned about the 335i engine:

"Young powerplants are expected to have teething problems, in all new-model BMWs. It's not like the 1980s when new-model BMWs were tested out the wazoo before being put into regular production. Nowadays, the competition is way too fierce for that; the lead times are very short. Final R&D is literally being left to the dealership technicians to figure out".

Quick comment about 335i vs E46 M3:

"I loved the 335i coupe I tested for Bimmer magazine for 1,200 miles. I had some niggling complaints, but overall the car was superb -- and there's no question it handles better than a stock E46 M3. Whether it's more fun is a different question, and one that I would answer in the negative. The 335i is truly an oustanding luxury GT and it would unequivocally be my choice for year-round use or long road trips. Either car is excellently suited for daily use, but in terms of winter set-up, I think the 335i would edge out the E46 M3."