The automatic in the 540 is also discussed, and how it supposedly can’t handle the power and torque of the S62. But as one commenter rightly points out, Dinan has a kit that successfully boosts the power of the 540 to more than 400 hp, and can be used on BMW’s automatics. While it’s going to be difficult to make an auto work with the M5, knowing that you can use a 6-speed tranny off an E39 540 is a nifty bit of information, because you can look for this component at a wrecker or parts dealer as a 540 transmission, instead of asking for an E39 M5 transmission, which would likely drive the price up.

See the discussion here.

Knowing that he had a new sensor, the owner proceeded to consider other possibilities, such as the thermostat. Luckily for him, a helpful board member insisted that he learn to DIY the thermostat replacement himself after he mentioned that, while Toyotas and such we easy to replace, German cars were harder. Maybe harder to get to but not harder to replace. Upon doing his research online, he also found that he had replaced the wrong sensor. So now, he’s replacing that sensor and checking the thermostat.

As with most M cars, it’s always a good thing to do DIY work. The benefits are many. But the lesson here is to thoroughly research the job so that you do it right the first time. There is a lot of help and information online and little repairs like these are within the reach of the average joe.

Read about this E39 M5 owner’s experience here.

It turned out that the culprit was an improperly tightened set of bolts that attach the bearing housing to the hub assembly. Not knowing that there was such a set of bolts, this owner didn’t know of a potentially disastrous failure had the hub and bearing assembly separated. Once again, the collective knowledge of like-minded individuals contributed to what turned out to be an easy fix.

As a side note, we love owners who do whatever work they can on their E39 M5s. Aside from saving money in labor costs, working on your BMW M5 enables you to learn about your car and anticipate what things can go wrong or merit some extra attention.

See rear wheel bearing discussion thread here.

What’s nice about this track is it’s got plenty of straights that lets the driver floor the throttle for long periods, allowing the engine to rev high on its powerband. That’s when you hear the engine’s sweet song. And when it hits those straights, the acceleration is be pretty fierce because the car following in the back becomes a mere dot pretty soon. As an all-around car able to take to the track with little preparation, the E39 M5 is highly unique. Sure, a Porsche can do the same thing, but the M5 can then do duty the following day as an executive transport or as a tourer. Even do duty as school transport. Few cars are as versatile as that.

See that rear facing video here.

Two points of interest entered this discussion thread, one being that not all aftermarket 17-inch wheels necessarily fit the E39 M5. The other is a suggestion to use front-sized tires for the rears, as this will give better performance in snow conditions. It must be equal parts fun and scary to be driving an E39 M5 out in the snow. A light and gentle foot is certainly required if we don’t want to see these cars against a snowbank or worse, a tree. It would be better if an E39 M5 is garaged for the winter but not all owners have that luxury.

See the discussion here.

But if a guy goes into owning an E39 M5 with both eyes open, as this thread helps illuminate, and is not afraid to get his hands dirty from time to time, then owning such a car will be a truly memorable experience.

See E39 M5 ownership opinions here.

There’s also some discussion on where to get the specialized Torx bits to allow replacement of the MAF. Unless you want a BMW-stamped tool to work with, these Torx tools are available at most electronics supply stores. As always, you get what you pay for and it’s not advisable to buy those twenty dollar tools sets. Improperly fitting bits can gouge or deform the heads on the screws and you will only end up with more work to do.

See the thread here.

The owner just decided to sell the whole car rather than deal with the problem. Although the asking price was for 8k as is, the final sale price was not mentioned. It’s hard to judge the owner for seemingly giving up so easily on such a great car because there are a lot of options for an enthusiast to bring such a car back to life. With a tuned chassis like that, an ordinary 540 engine with forced induction would give a lot of power. We’ve also seen an E39 M5 with a turbocharged Toyota 2JZ. Although it’s blasphemy for the purists, such an engine can easily produce 600 hp without breaking the bank.

Let’s just hope that this car didn’t end up at LeMons, as one poster offering 500 dollars for the car threatened to do.

See the thread here.

The advent of graphics programs like Adobe Photoshop has enabled enthusiasts to see the effects of their intended mods on the screen, even before spending a dime. While the colors above would not be to everyone’s taste, a roof with a carbon fiber weave has been an acceptable aesthetic mod ever since the M3 CSL showed its possibilities.

3M makes a very nice carbon fiber wrap that looks like the real thing and has apparently been used to clad a whole E60 M5. For an accomplished and patient do-it-yourself E39 M5 owner, playing with this material is a cheap way to alter the looks of your car.

See the discussion here.

It’s interesting to note that one owner replaced his alternator with one from an X5. This is certainly a viable proposition, as the alternators from an X5 should have improved reliability. The fact that it is not an M part would also be a reason for it to be cheaper. It’s also noted that the 540’s alternator is water-cooled whereas the M5’s is aircooled. Wonder what BMW’s reason is for that disparity. At any rate, heat is just one reason for an alternator to fail and as mentioned above, these components do wear over time and can fail without warning. If your E39 M5 is getting long in the tooth, it would not be a bad idea to do some preventive maintenance at this point. Better yet, get another alternator, have that refurbished and use it while having the original one rebuilt as the spare.

See the discussion here.