gavriil

From Autoweek:

(12:51:38 Nov. 27, 2002)

Munich, we have a problem: A cadre of owners raises brow—and stink—over M3 engines gone bad


By JOHN D. STOLL


“The BMW M3 is about as good as it gets.”
So read our conclusion in January after whirling an M3 around a California track and rummaging through our mailbag of owners’ comments. Then came word of engine failures.

While little has been reported about possible main bearing or connecting rod problems with M3 engines built in 2001, the problem is real, admitted by BMW, and extensively documented online at members.roadfly.com. Some 112 owners have logged complaints via the website, detailing extensive dealings with dealers. Many have had engines replaced with no explanation of what went wrong.



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BMW sold 13,408 M3s in the United States over the past two years through October. Only a small percentage of owners have reported an engine failure, said BMW spokesman Gordon Keil. Those who are familiar with the situation estimate that as many as 500 owners worldwide have had problems. The automaker acknowledges “probably under 100” cases in the United States.

The problems appear isolated to models built between November and December ’01. However, the earliest reported case on the website was posted in October 2001. That owner (who signed a non-disclosure agreement and is limited in what he can say) reported the exhaust valve broke, touched the No. 5 piston, and leaked sodium throughout the cylinder. His M3 convertible was replaced.

“It’s no big deal that the car has a problem,” says another owner, John Turkell, whose often track-driven November ’01-built M3 continues to run with little difficulty. “This is a safety issue. I don’t want the engine to go with six cars bearing down on me.”

Though Turkell’s engine remains intact, he is one of the most vocal owners, fueling much of the discussion on members.roadfly.com. Turkell and other owners refer to the M3’s 3.2-liter, 333-hp inline six as the “Engine of Damocles,” suggesting the engine can blow at any time, and that the issue could eventually hurt resale prices. BMW doesn’t see evidence of plunging values and has not issued a recall. It has changed some engine parts and recommends 10W60 weight oil instead of 5W30. But BMW says the changes are not due to engine failures.

BMW North America is dealing with the blown engine issue “on a case-by-case basis” and won’t say how many engines have been replaced or what ills them. Owners have been told “The M Group in Germany [is] still methodically researching the issue.” BMW encourages owners to follow break-in guidelines, pay particular attention to oil levels, warm up the engine properly and not to rev in excess of 8000 rpm.

Wayne Sadin, whose engine shut down at Texas Motor Speedway during a warm-up lap, was pleased with BMW’s response.

Sadin said his Bimmer “was fixed quickly, courteously, and without any fuss or acrimony” within two weeks. “My attitude is that highly stressed things break, and as long as they fix them with minimum hassle, that’s cool.”

BMW’s suggestion that over-revving or missed shifts led to most failures is disproved in that failures have come in M3s fitted with sequential manual gearbox transmissions, which in theory electronically prevent over-revs. Many owners have checked the onboard computers to find failures occurred with engine speeds as low as 4000 rpm.

Even if owner abuse is the case, BMW may still replace the engine. BMW claims to be replacing one owner’s engine that was run to 9000 rpm, causing significant valve damage. Nevertheless, here’s one suggestion: Don’t push BMW’s benevolence.

gavriil

I know this is not new but now it's getting out much more than before. I hope so. Cos our tranny problem I think was less sever and we saw articles on the Washington POst and elsewhere. BMW deserves a good punch for having such a sever problem with one of their flagship cars. It will make them better.

DtEW

The problem derives from a basic issue with the I6 configuration:

It has the longest crankshaft for any given engine displacement.

(Assuming a comparable stoke-to-bore relationship and not something ridiculously oversquare/undersquare, of course.)

Back in the really old days of automobiledom, before metallurgy was as advanced and affordable as it is nowadays, engine builders ran into problems with the length of the I6 crankshaft. It would fail. Some engine builders resorted to clever engineering and took power off the crank through the middle, via a cog between the 3rd & 4th cylinders, effectively halving the torque subjected to the most stressed part of the crank.

But modern metallurgy has ensured that modern I6's have none of these problems. In fact, their natural balance and 7 main bearing journals (V6 and V8 each have only 5 main bearing journals) have made them one of the strongest and most durable engine configurations, given a normal build, not to mention an overbuild such as the 2JZ...

But that's why the E46 M3 has problems. What BMW has tried to to do is to combine both high-displacement torque (3.2-litre) with revs (8000rpm!) The only way to go about that is to pare down rotating and reciprocating mass to its bare minimum. What has basically happened is that BMW has stretched current metallurgy to its limits, and has taken a bit too much off that long crankshaft to reintroduce old-time problems.

Consider that 8000 rpm is also what Honda deems an acceptable redline for a 3.2-litre high-output engine (C32B). But consider that it's a V6, with a much shorter crank, and reciprocating/rotating mass lightened via mostly by the titanium con-rods, instead of shaving steel off everywhere, as BMW apparently overdid.

Yes, I'm also suggesting that an F/I'ed e46 M3 is a timebomb.

Gabo3k

Wow! This makes for good reading/education.

Thanks for the valuable input.

I thought that the in-line six was one of only three engine configurations to be naturally balanced (among V12, and opposed six).

I't seemsBMW has tryed to over-engineer the in-line six. The same thing I read in a Road and Track article about CL-S sportshift transmission.

I't seems "supposed" over-engineered items are doomed!

bkknight369

...man, and we though Acura couldnt come to grips with the problems with the cl and tl...

DDT-TypeS

Just so you know my 2003 CLS 6spd had an engine failure too! They replaced the engine block (lower) due to a bad beaing or whatever.

I know of only one other 6spd CLS with a similar problem like mine.