For New Owners - What I wish I knew when I first bought my E9X M3:
1. The best info on M3Post is found in the less travelled E90/E92 M3 "Technical Topics" subsections - Engine, Wheels, Suspension, Cosmetic, Coding, DIY, Maintenance, Detail and Track. Notice how this "wish I knew list" is posted in the General Forum section? Caveat emptor.
http://www.m3post.com/forums/forumdisplay.php?f=123
2. The E9X M3 has a hidden software setting to tweak the M Dynamic Mode MDM feature. Hire one of the many remote coders on this website to adjust the software settings in your to the "Euro" MDM settings. This really livens up the car by making the traction control way less intrusive without being completely turned off for those extreme mistakes. This is one of the areas where the BMWs really shine vs the Mercs.
http://www.m3post.com/forums/showthread.php?t=956396
3. The E9X M3's S65 motors tick and click, it's normal.
http://www.m3post.com/forums/showthread.php?t=1167323
4. Some brands of oil are less noisy than others when used in the S65 engine. The ridiculously named "BMW Twin Turbo Power 10W-60" oil and Shell Helix 10W-60 oil (which may be one in the same, just with different labels) are two of the quietest options.
http://www.m3post.com/forums/showthread.php?t=1350805
5. The E9X M3's DCT transmissions shift clunky at low speeds and switch between drive and reverse slowly, it's normal. They make up for laggy slow speed performance higher in the RPM range and at higher speeds. If you really dislike it, tuners sell a DCT software tune (usually called the GTS DCT tune) that smooths things out more via software only.
http://www.m3post.com/forums/showthread.php?t=1091635
6. The E9X M3's DCT transmission is nearly bullet proof. BMW made amends for the absymal reliability of the SMG transmission before it.
http://www.m3post.com/forums/showthread.php?t=894069
7. The water pump on the S65 is bullet proof, BMW got this one right. This is another area BMW made amends for one of the previous generation model's shortcomings.
http://www.m3post.com/forums/showthread.php?t=1373126
8. The E9X M3's two throttle actuators are made of glass (figuratively). They will eventually fail you and very often the second one will fail shortly after the first. There is a "hidden warranty" of sorts where failing throttle actuators will be replaced free of charge if they fail in the first 7 years or 70k miles for cars registered in California Emissions states which include: California, Connecticut, Maine, Maryland, Massachusetts, New Jersey, New Mexico, Oregon, Pennsylvania, Rhode Island, Vermont or Washington
http://www.m3post.com/forums/showthread.php?t=1312330
9. The E9X M3 deflection pulley (aka idler pulley) fails early and often. It's a low cost replacement part (by BMW standards) and easy to DIY if you want. A squeal from the engine bay of an S65 is almost always this part self destructing.
http://www.m3post.com/forums/showthread.php?t=1162212
10. Nearly all BWM E9X M3 maintenance parts are purchased by BMW from another company, placed in a BMW branded cardboard box, marked up 25-100% and then sold to you as the official BMW replacement part. Surprisingly, most of those exact parts BMW buys can be bought by you for a lot less. Check out this link for all of the exact factory matched parts ID'd so far.
http://www.m3post.com/forums/showthread.php?t=1343867
11. All E9X M3's are or were part of the Takata airbag recall. Many E9X M3s now are part of the main positive battery cable recall for the cable that runs from the battery mounted trunk to the fuse panel behind the glove box. 2013 model year E9X M3s have an extended warranty for the idle control valve for 10 year or 120,000 miles.
http://www.m3post.com/forums/showthread.php?t=1224855
http://www.m3post.com/forums/showthread.php?t=1373697
http://www.m3post.com/forums/showthread.php?t=1251633
12. The E9X M3's original batteries were Absorbed Glass Mat (AGM) group 49 type battery, 900 Cold Cranking Amps (CCA) and 90 Amp Hours (Ah). You can't buy those exact specs anymore. Instead the BMW batteries for the E9X M3 now offers AGM group 49, 850 CCA and 92 Ah, which are the same specs as the Sears DieHard and Autozone Duralast AGM group 49 models.
http://www.m3post.com/forums/showthread.php?t=1194030
13. If your E9X M3's A/C is low on freon its most likely the evaporator failing. It is built of especially low quality. Good news is the replacement part is not too expensive. The bad news is your dealer will likely charge you for a full day or two of labor. If you have any warranty remaining, have someone take a close look at the condition of this part before it expires.
http://www.m3post.com/forums/showthr...=666116&page=2
14. The E9X M3's S65 motors respond really well to early replacement of the spark plugs (the car's manual calls for 37,000 mile service intervals). You really can feel a difference, even if the spark plugs coming out of the car only had 10,000 miles on them. This is a great afternoon project if you are eager to improve the performance of your new to you M3. Consider doing this inexpensive upgrade instead of breaking out that black Krylon to tint those rear tailights.
http://www.m3post.com/forums/showthread.php?t=471690
15. E9X M3's wear through motor mounts really fast, as within 30,000 miles they can start to fall apart. Changing them out earlier than you would for another model car makes for a measurable and immediate improvement in the shifting of your car. Don't bother with the transmission mounts unless you are over 100k as they hold up very well.
http://www.m3post.com/forums/showthread.php?t=1005111
16. Code readers, either a stand alone unit or a cell phone app type with a bluetooth/wifi OBDII port adapter, are great for this car. Buy one asap.
http://www.m3post.com/forums/showthread.php?t=1149024
17. E9X M3's are much more fun to drive than to look at.
Experienced E9X M3 owners, feel free to add to the list!