I just spent a couple of hours researching E46 M3s in various worldwide owners forums... and found out a lot of really bad and outright unacceptable information.

I was first alerted to this problem when some fellow instructors were discussing the fact that they knew of over 23 total engine failures had occurred in Open Track events... and that BMW was not being fair to the owners.

There is a lot of finger pointing going on about this... first it was publicly thought that only SMG-equipped cars were blowing up. But, fact of the matter is that all kinds were destructing... both 6sp and SMG cars. And, both "hard" drivers and daily drivers.

There has been a tremendous trove of information published... videos of blown engines, pictures, dealer repair invoices, and even BMW documents. See the links below.

Engine Failures

There are several dozen documented failures. Many - but not all - are cars with the SMG system - which theoretically shouldn't allow the engine to go over redline under any circumstance. Seems that there is a problem with the rev limiter - while some of these engines died in (very) normal driving, some died after having gone over the rev limit. Now of course there are purely mechanical reasons why you might accidentally go over the rev limit. But, these are clearly not cases of that. In fact, the M3 engine control computer records and stores the maximum RPM the engine achieved, how long it stayed there, and how many of times it's gone over the redline. Some blown engines appear to have gone as much as 8500 RPM.

Seems that there are issues in the crank, cam, valvetrain, and rod and crank main bearings. The sites below document many changes BMW is making to the engines in production.

And, BTW, a replacement engine swap costs you up to $17k US. Many owners have had to pay it themselves. BMW is being obstinate... there is a lot of fighting going on.

Press

I've been reading the press articles in European and Japanese magazines since the car was announced. I was at the N.A. Press Introduction for this car, I still have the press kit (unlike some cheapwads, I get them for the right reasons and don't immediately put them on e-bay - in fact, never!). All of the initial press was positive, tremendously enthusiastic. But, very few mags say anything after a year of "enthusiast"-style (aka hard) driving of the cars they review - most initial articles are marketing blather. Only a very few mags have anything to say after a period of time - U.S. mags are especially bad on this point. BMW is the golden child of all the golden children.

The truth starts to come out much later.

Other Issues

Some of the excellent British car mags have done track testing of the car... one test on a challenging track with lots of elevation changes and braking said the stock brakes stunk and faded away after only 3 laps. I personally find it inexcusable that a 50-60k car doesn't have at least 4-piston Brembos up front, 2-piston rear.

Best Motoring, one of my favorite magazines (even though it's a video, it's still a "magazine"), has tested several M3s, both with and without SMG. See the link below for a very interesting test of a couple of EVOs, versus a pair of M3s (w/ and without SMG), and a pair of Modenas. It's interesting to see who wins. Hint: the M3s loose.

Other mags have complained about the constant oversteer... one video segment has the car sideways for nearly the entire lap (while this might be fun, it's slow and it damages the car).

The limited slip diff uses an internal pump to drive the clutches together... this is an advanced technical feature but results in an extremely hot diff in track usage. This is clearly a car which would need a diff cooler for serious Open Track usage.

Then there is the SMG-equipped transmission. While nobody can blame the engine failures directly on this tranny (although as pointed out above it should electronically stop over-revs), it does look like a contributing factor in many cases. And, the tranny itself is getting bad reviews from some owners. Seems that we don't even get the full package Europe and the rest of the world gets... we get watered-down programming with 1 mode missing entirely. Many owners want it reprogrammed to the full Euro spec... and some people even complain about that. While this is a technology that is not "before it's time", it's clear that the implementation may well be.

Summary

I'm very disappointed. This is a car which I was considering... one I could afford. But, I expect a certain degree of quality engineering from BMW and it's clearly not there. Will the car be better after a year or two? Who knows... but I do know that if anybody manages to talk me back into this car I would be extremely cautious with this engine on the track, and I won't go anywhere near the SMG.

Disclaimer - I'm not one of these owners who publicly exclaim that whatever they happen to own is *absolutely perfect*. The S2K is not perfect, the dealers are not perfect, but the car is obviously far more reliable and better engineered compared to the far more expensive E46 M3. I am a fan of the E36 M3s, and several other cars of various other brands. I am a very *hard* driver on my own cars, and I've probably driven 40 other types of cars on the track over the years. I do have high expectations.

References

1) BMW E46 M3 Engine Failure Archive (extensive documentation, videos, dealer invoices, BMW factory information)

2) Best Motoring video - M3s vs EVOs vs Modenas

3) M failure dot com (video w/sound of blown E46 M3 engine)

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crazy isn't it? Two have reportedly self destructed at TWS, one an SMG. One of the instructors owns one (Julie) and she said no more track time for her M3.

OTOH, in the most recent issue of the Roundel (BMW CCA publication) printed an article about the issue. BMW NA argues that the severity of the problem is overblown, as is the case with such things on the internet.

Some good gearhead sleuths have been able to find part number changes month by month during the M3 build cycle, relating to valvetrain, crank, etc.

Not sure what to make of it all, except that I'm certainly staying away. And, at the weight of the E46, I'm not too keen on trying to keep tires and brakes on the damn thing.

 

I fail to see how Brembo's with more pistons would alleviate the brake fade problem....As has been mentioned, more pistons does not always mean better braking.

And I have always been told brake fade had to do with the temperature of the brakes and the brake fluid. Would upgrading the fluid not solve a bit, plus trying to improve airflow to the brakes? I mean, as nice as BMW wheels are, most that I have seen don't look like they offer the most ventilation. Or just getting some slotted rotors and upgrading brake pads....All these seem much more effective and less costly than just slapping on a Brembo kit.

Blake

 

It's *engineering*. They didn't invent racing calipers for looks, although some people add them for such.

Upgrading the fluid is not a complete answer at all, just like adding water wetter won't fix a cooling issue.

 

I just fixed the references... take a look at M Failure .com - look at the first video on the left. That's the first sign of what a broken engine sounds like. Then, the second video to see what happens on the track when one blows. It's catastrophic.

 

I didn't say just upgrading the fluid...I mentioned several other options (namely brake pads/slotted rotors) which would probably provide a huge decrease in brake fade at much less the cost as a set of $2000 Brembos (Or however much they cost!)

About to take a look at the vids...

Blake

 

Don't count on any "huge" decrease in brake fade without upgrading most or all of the system. If the car is seriously tracked pads and fluid have already been upgraded. I've discussed this matter with track veterans and most concluded that any significant decrease in fade (for road cars) only came after plenty of money was spent. I would also agree that a car in the class of the M3 should have comparable brakes to Porsche for instance. At the prices these cars command two grand or more for an applicable Brembo system (likely much more as a factory option) would be a small price to pay for the benefits on the track and small in comparison to the sticker price. On the street however much of the system's value could be overkill as stopping distances remain similar with Brembo vs. OEM despite increased brake fade and resulting pedal effort.
Sounds like keeping the engine intact is more of an issue here. Nobody wants to worry about grenading an engine on the track. That's something best left to the F1 drivers not the weekend warriors.

 

[QUOTE]Originally posted by svann
[B]Don't count on any "huge" decrease in brake fade without upgrading most or all of the system.

 

Not exactly... some cars have large iron calipers. Some calipers of any type of very thick walls and are less prone to shed heat. There are many differences in piston material. Single very large pistons (as large in my experience as 73mm) will also retain heat. Brembos - and similar brands - are designed with some care in the internal fluid passages and wall thicknesses. They will perform a lot better than most OEM calipers (and some of the latest aftermarjet calipers which are massivcce lumps of castings, or CNCd castings).

More pistons and bigger pads will have a huge effect - imagine two scenarios in the otherwise-same car. One has 14" rotors and 6-piston calipers... internally vented multi-piece rotors - huge swept area. The other has the standard 11" rotors (cast iron), and single piston cast iron calipers. In both scenarios, the car has to stop repeatedly from 100 MPH. Who is going to fade first? Who is going to stop in a shorter distance? Answer is obvious.

Big brakes and rotors are a must.

You mention air flow... there is also air flow around the caliper, thru the rotor (axially and thru the hub), and there is venting via drilling (which only lasts in rotors designed and cast to be drilled - aka not ours!). A few race cars even water cool the calipers. Air flow, is of course, a very large problem in the backs of cars.

They would stick up for their own cars. But owners web sites don't. And there are still failures worldwide in 2002. Who is to say it's truly fixed, esp. when you have a bunch of burned people who refuse to go back to the track? How do we know?

And, would anybody a few years from now be nuts enough to buy an early E46 M3 as a track car? Who is to say whether it's a "fixed" one or not - or what # engine it's on (contrary to popular belief, buyers services don't always have access to all the warrenty work that has been done)...

 

[QUOTE]Originally posted by svann [B]Don't count on any "huge" decrease in brake fade without upgrading most or all of the system.