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BMW M3 Maintenance and Repair



  • can anyone explain why a stock e46 m3 motor can reliably run on a activeautowerke supercharger kit but not for a turbo set up without changing to a lower compression piston?

    if the oem e46 m3 compression is not too high for supercharger, shouldn't it handle a turbo set up at the same psi assuming the CFI flow rate is the same with same size injector, tuned fuel map..etc?
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 55,846
    But who is claiming that, the maker of the supercharger?

    At any rate, they might be right. Turbos create more heat than SCers and also more 'surge' of power. SCers run cooler and offer a wider power band.

    So I could see this argument being correct in principle, although I could also see how the engineering of the particular kit could change the reliability factors either way.

    I guess it also depends on what PSI both these systems run at.

    Bottom line is that ANY bolt on kit, SC or turbo, is going to reduce engine life ultimately. You don't get something for nothing. You can take 10% right off the top on either application IMO.

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  • Very interesting. I never realized turbo will have more surge if it's the same psi with same CFI and I always thought a good intercooler will make turbo as reliable as SCer. But that explanation makes sense.
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 55,846
    It makes sense to me, too. I mean, if you think about how the turbo delivers power, it does come on all at once whereas a SC is a gradual buildup from idle. Also given that the turbo lies adjacent to the exhaust system one would expect more heat whereas the SC is often up top in a cooler region. I betcha turbo intercoolers work harder and can't shed heat as fast.

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  • Does anyone know what repair manual I can get other than Bentley? I just got the Bentley manual and it did not include cylinder head work for M3 motor. So I don't have the torque spec to install the oil seperator on the head. :confuse:

    Any advice will be appreciated. Thanks!
  • roadburnerroadburner Posts: 9,619
    Any advice will be appreciated. Thanks!

    Like I said in post #114, join BMW CCA. You will then have online and phone access to the club's technical advisors.

    Mine: 1995 318ti Club Sport / 2014 M235i / 1999 Wrangler / 1996 Speed Triple Challenge Cup Replica Wife's: 2016 i3 REX/2004 X3 2.5i Son's: 2009 328i

  • dwjldwjl Posts: 1
    I took my car in to the dealer for a recall (2002 M3) and they told me I need the euro valve and the power steering hose changed because they are both leaking. They quoted me $900 for the euro valve and $650 for for the power steering hose. I came across your thread after doing some research the the web. Did you fix the problem your self? If yes, was it hard to change out? Thanks for your help in advance.
  • Hey all, seems like there is a lot of people here who know their stuff, so I am seeking some help....I am shopping around for a 2002 or 2003 M3, but obviously with a car that is out of warranty, I am a little nervous shelling out for a used vehicle that could potentially have a lot of reliability issues. Any thoughts on reliability, maintenance costs, etc? Any "horror stories" out there with an M3? I am kind of torn between an M3 and a 2005-2006 G35, solely for the fact that there are tons of certified pre-owned G coupes in the Chicago area for a comparable price. As one poster said earlier, however, I would be willing to "roll the dice" on an M3 out of warranty if the reliability is sound.

    Thanks in advance!
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 55,846
    Well you have to do your homework and go in with your eyes open. Probably most people who have had bad luck with these cars out of warranty did not perform due diligence during the purchase process.

    If it were me, I'd:

    1. Find out all the problem areas by doing research

    2. Buy the BEST M3 you can afford. No projects, no question marks, no salvage titles, no cars with zero service history, no cars titles from Louisiana, Alabama or New Hampshire.

    3. Have the car meticulously inspected by an M3 specialist.

    Doing all this, you've improved your odds 90%. Is all this a guarantee of a happy life? No, it isn't but you are WAY ahead of the average buyer.

    Here, this will get you started! #cooliris

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  • roadburnerroadburner Posts: 9,619
    The E46 M3 has proven to be pretty reliable overall. There were some engine issues early on any car you look at should have had the problem corrected by now. I always recommend that any potential BMW owners join the BMW Car Club since so many dealers and independent shops offer discounts on parts and/or labor to club members. The local Chicago chapter(Windy City) is one of the most active and friendly groups as well. I'm sure that you will find members more than willing to advise you regarding the purchase and servicing of an E46 M3. Best of all, they conduct a terrific Drivers School at Road America- made to order for an M3!
    What you must keep in mind is that you need to service any BMW by the book. Cutting corners on maintenance will end up costing more in the end.

    Mine: 1995 318ti Club Sport / 2014 M235i / 1999 Wrangler / 1996 Speed Triple Challenge Cup Replica Wife's: 2016 i3 REX/2004 X3 2.5i Son's: 2009 328i

  • I do agree with the advice above that is best to have a certified BMW mechanic to go through the inspection before purchasing a used M3. I bought mine a month ago. The car looks, feels, sounds and drive like a new car. But luckily I ask the dealer to do the same list of visual inspection check as they would for their own certified pre-own. That cost about $125. But more importantly, I also asked them to do a compression test to make sure the engine is stil fresh and do a driving inspection. That cost another $400. It was $ worth spend because they found leaks from the oil seperator and power steering hose which could cause some major damage. I would have never been able to discover that myself from test driving it.

    Now I am driving my M3 cautiously until I get it fixed. This is where I'm stuck and need help I need to change the oil separator, part # 11-15-7-830-948 and the new O-ring. I purchase the Bentley repair manual and join the BMWCCA as recommended. However, the manual did not have any torque specification for installing a new oil separator. Some of the TSA that I have contacted from BMWCCA either couldn't help me or told me to call a dealership. I was not able to get the info from a local BMW dealer either. I have the parts and the diagram. I'm sure I know how to do it right if I have the torque spec so I don't over or under tigten. And I really don't want to spend over $800 in labor if I can do it myself. If anyone know the specification or know who I can speak to that can help me, I would appreciate the assistance.
  • I haven't changed it yet. But it's one of those things that it shouldn't be ignored. I got the euro valve, aka oil seperator from the dealer and it's like $60 and the O ring was about $10 I think. I got a diagram from the dealer and it seems pretty straight forward. But right now I'm stuck cause I don't have the torque specification and no one seems to know. Once I find the torque spec, I should be able to change it in less than an hour or two. As far as the power steering hose, I need to wait till I can get it on jackstands because you can only reach it from the bottom from what I can see. That will be more difficult. According to a website, the power steering hose should all be changed the same time along with the reservoir since it has a filter in it.
  • The M3 is so much better than the G35. The M3 runs neck to neck with porsche carerra and msrp was $20,000 less then carerra. Depending what price you are looking for, you might find a 2003 with extended warranty which ends in 2009. Also, if you are going to get infiniti, the new G37 is a much better car. 330 HP for $32,000 msrp vs the m3 333HP for $48,000 msrp. But then again, I love my used M3 and not sure if the G37 can handle like the M3. Just make sure you get the M3 to BMW for a full inspection, test drive and compression test by the mechanic and that will give you most of the warning signs that you will have to face.
  • fedlawmanfedlawman Posts: 3,118
    In terms of sporting abilities, I agree the E46 M3 is a step up from the G37 (not necessarily in HP, but in handling/chassis dynamics). But to compare it to a Porsche 911 is absurd.

    The M3 is a bloated, understeering land barge compared to the 911.
  • but is the carerra really worth $20,000 more? Which is more car for the $. There are so options to improve the M3 with extra $20,000 that can make the M3 out perform the carerra at tht point. Let's face it, unless some people buy the porsche for the name to show off their wealth, otherwise most people buy it for the excitement from the performance side and the M3 performance spec is pretty comparable if you put them side to side.
  • roadburnerroadburner Posts: 9,619
    If anyone know the specification or know who I can speak to that can help me, I would appreciate the assistance.

    You might try posting your question on some other M3 forums. I'd also recommend joining the Yahoo E46 M3 group. If all else fails, you can always go to the BMW NA Online Tech site and pay $30 for 24 hours of access.

    Mine: 1995 318ti Club Sport / 2014 M235i / 1999 Wrangler / 1996 Speed Triple Challenge Cup Replica Wife's: 2016 i3 REX/2004 X3 2.5i Son's: 2009 328i

  • roadburnerroadburner Posts: 9,619
    otherwise most people buy it for the excitement from the performance side and the M3 performance spec is pretty comparable if you put them side to side.

    True enough, but I have to agree with fedlawman in that the 911 is more agile and involving, primarily due to its lighter weight and compact size. Don't take it as a knock on your M3, as it's a great car. Still, given the choice I'd also go with the 911- assuming I didn't need a usable rear seat...

    Mine: 1995 318ti Club Sport / 2014 M235i / 1999 Wrangler / 1996 Speed Triple Challenge Cup Replica Wife's: 2016 i3 REX/2004 X3 2.5i Son's: 2009 328i

  • fedlawmanfedlawman Posts: 3,118
    "is the carerra really worth $20,000 more?"

    Is the M3 worth $20,000 more than a Honda Accord V-6?

    "There are so options to improve the M3 with extra $20,000 that can make the M3 out perform the carerra"

    There are so many options to improve the Accord with the extra $20,000 that can make the Accord outperform the M3.

    "the M3 performance spec is pretty comparable if you put them side to side."

    BMW E46 M3 - 3415 lb curb weight; 107.5" wheelbase; 0-60 in 4.8 secs; 1/4 mile in 13.6 secs
    Porsche 911 - 3075 lb curb weight; 92.5" wheelbase; 0-60 in 4.3 secs; 1/4 mile in 12.8 secs

    No comparison. The M3 is a Grand Tourer - the 911 is a Sports Car
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 55,846
    Such DIFFERENT driving experiences! The comparison seems forced to me.

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  • fedlawmanfedlawman Posts: 3,118
    I agree - the comparison just doesn't work on so many levels.

    I can only guess that GMonkies has never driven a Porsche.
  • Wow, I never realized I can ruffle so much feathers with my believe based on the info from magazine report. I was only trying to give a fellow BMW enthusiast a point of view based solely on the 1/4 mile time as one of many measures. But I will entertain the comments and continue with this debate one more time. My recollection was that when Road and Track magazine introduced the 2001 E46 M3, they have listed the M3 to be 0-60@ 4.8 and 1/4 miles to be 13.3 sec msrp at $48,000. On that same magazine it listed the 2001 porsche carrera to 0-60 @ 4.6 sec and 1/ mil to be 13.2 sec msrp ~$70,000. 13.2 sec is a big difference to 12.8. I could be wrong but I think 2001 porsche turbo was around 12.8. Too bad I no longer have that magazine anymore, otherwise I could have scan it and e-mail it to anyone that wants proof. If I'm talking out of my [non-permissible content removed] with the spec then, it's really the magazine's fault for wrong info. Luckily we have google and there is a site that listed the porsche spec from both 2 magazine which backed up my numbers.

    I have to admit I have only been a passenger in a porsche and have not had the opportunity as a driver yet. But I'm not here to knock down porsche or saying that the M3 is better, I'm just expressing my personal believe, "what is more car for the dollar". And to tell the truth, since porsche and bmw are both german built, rear wheel drive car dedicated to racing, It's not so insane to compare the 2. But comparing a front wheel drive Japanese built honda accord is probably more absurd. When I first started in the import scene 10 years ago, our goals were to spend less and yet still be able to spank a porsche, vette, viper..etc. And yes, I know kids out there that had a turbo civic/integra and out ran Ferrari and Lambo on the street. So Yes, I can spend $20,000 to rebuild the motor and put a turbo into an accord so it can outrun the M3 and the porsche turbo easily in 1/4 miles. But as a front wheel drive car, it can only get enough traction with drag slicks, not street tire. But drag slick cannot handle road course. Lastly, there are some road course that favors front wheel drive car and some that favors rear wheel drive car. So comparing front wheel and rear wheel drive is hardly a fair comparison. Comparing the M3 to the new G37 for example is a fair comparison cause they are both rear wheel drive so they can fairly compete on the same road track. Several magazines had compared the s2000 to the porsche boxster. Yes the S2000 requires more effort then the boxster. But the lap time and 1/4 mile time is very competitive. So is up to individual's opinion which is a better car for the $ and if it's worth the extra $. I don't think there is a right or wrong answer to this.

    As a Honda lover my I've spent enough $ building several civic and integra for drag and road course to have been able to buy a new m3 cash. I am still able to admit that there are other car more for the money. As much as I hate domestic, Dodge neon SRT 4 is a lot more car for the $ to "ME" than the acura rsx type s. But that's just my opinion.

    I was told once by a wise man, opinion is like Ahole and everyone's got one. With that said, I will step off my soap box now and stand by my believes while others can do the same.
  • fedlawmanfedlawman Posts: 3,118
    No ruffled feathers here, I'm just saying I disagree with you. Believe it or not, I don't own a Porsche (I actually own a BMW).

    There's simply a lot more to a car than magazine test numbers for 0-60 MPH and 1/4 mile acceleration.

    If driving the Porsche is like swimming in a crystal clear swimming pool, the BMW, by comparison, is like swimming in maple syrup.
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 55,846
    I could build up a car to beat either of those 0-60 or 1/4 mile times for far less money than either an M3 or a 911, but you wouldn't want to ride in it for very long :P

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  • fedlawmanfedlawman Posts: 3,118
    No need, this will suffuce...

  • that was kinda the point I was trying to make too. My civic and integra are so harsh with absolutely no luxury, comfort, prestige. I meant no disrespect to others passion and if I can afford the 911 turbo, that would have been my choice too. I do agree there is something to be said when you can drive a turbo car with less road noise and can turn on the AC in the summer time.
    For now, I'm just happy to finally own the m3. As a novice with BMW, I join the forum to seek advice on fixing the M3 myself to save some $. Not to insult anyone or pick a fight.

    p.s. I manage to replace the oil seperator thanks to everyone's advice. No leak so far. But then again, the old one did not have any signs of leaks at the seals either. Is it possible that it was leaking internally causing the vaccum to suck up oil, instead of air only, to the intake and that's why the dealer strongly advice immediate replacement to prevent lost of oil?

    Now my next task is to climb under the car and replace the power steering hose. Any advice of caution or tips to make the job easier?
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 55,846
    I can't think of any real snags other than having to pay for that hose. It's not cheap.

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  • fedlawmanfedlawman Posts: 3,118
    My hat's off to you, your handier than most car enthusiasts. I owned Honda's and Acura's for much of my younger years and I never did learn to turn a wrench.

    I've come a long way as a shadetree mechanic since joining the BMW cult, but I don't know if I could have done the job you did.
  • Should I buy new 19 inch Michelan tires from the BMW dealership, they want 421 per tire including installation? Should I trust Firestone to do it cheaper?
    Any advice?
  • roadburnerroadburner Posts: 9,619
    Buy them from Tire Rack; they sell the same Pilot Sports for $326. Use one of Tire Rack's Recommended Installers to mount and balance the tires. I'd stay away from mass market stores like Firestone or Goodyear unless you are 100% certain that they know how to service a performance car- otherwise you will likely wind up with scuffed or damaged wheels- and lug nuts installed by a gorilla with an air wrench...

    Mine: 1995 318ti Club Sport / 2014 M235i / 1999 Wrangler / 1996 Speed Triple Challenge Cup Replica Wife's: 2016 i3 REX/2004 X3 2.5i Son's: 2009 328i

  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 55,846
    don't take an M3 near a big chain store. :(

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