[Z4inAZ]

I really have no interest in continuing this discussion... people who work on the M70 know why it has the reputation it does. And there are tons of people who work on the M70 since so many of them break. Theres a reason these V12 paperweights are littering junkyards nowadays...

S38 and S14 yes had timing chain guide failures. But an owner of these engines should replace these preemptively - thats part of "maintenance" - when I say "well maintained" that includea preventative maintenance to prevent well-known problems.
S54 had rod bearing issues early in production but later models, keep up with valve adjustment and the S54 is pretty bulletproof. They have a few odd problems like the cam hub but there are a LOT of S54s on the road and very few have major problems with things like that
S62 is an extremely reliable engine, and my favorite BMW V8. With proper maintenance, these engines can last forever. I would even say they were more reliable than their M62 bretheren who had timing chain guide failures. Carbon build up should not kill an engine, the S62 needs to be revved hard to "blow out" the carbon. Babying an S62 kills it. Driving an S62 hard is maintenance for it VANOS is a more major problem for the S62 but it wont fail catastrophically, just sound like a diesel
M60 had its quirk's but BMW fixed it with the M62... BMW was still learning how to make its products work in all markets at this time

M70 had electic problems, fuel delivery problems, throttle bodies, crankshaft sensor... I could go on and on. The M70 is the modern BMW engine I have the least hours working on but also has the MOST problems associated with it of any BMW engine I have worked on.

The M70 engine block itself may be bulletproof, but EVERYTHING bolted to that engine to make it spin is a ticking time bomb.

Continue to debate if you want but I am speaking from personal experience not just conjecture and at this point any further discussion will just become "no, you" "no, YOU" kind of stuff.
Cheers

[Baggio850]

Having owned various 8 series from an early 4.0 840i to 3 850CSis I can't believe the amount of rubbish spouted by some people who have clearly never even sat in an 8 let alone owned or fixed one. The 850 is actually a very reliable car and was group breaking at the time of release. It was one of first, if not the first car, to have drive-by-wire throttle. It was the first V12 to be mated to a 6 speed gearbox and the AHK rear wheel steering gave it amazing high speed stability. The V12 unit is relatively simple and has no major issues. Electrical problems that have been mentioned here are usually a result of low batteries or hacked up wiring from alarm or stereo installs by people who don't know what they're doing. I've never had a major issue with the V12 through 10 years of ownership of various 850s. I would definitely recommend the V12, especially in CSi form, over the V8. In fact the only 8 I had problems with was my first 840Ci which needed an engine replacement due to the Nikasil issue.

I've just purchased another 850CSi, one of the last produced, and I'm in the process of restoring it. After a few weeks of being laid up it developed a misfire and was having starting issues. I called a friend who is an experienced mechanic and he said he wouldn't know where to start. My thoughts from reading forums was the distributor caps and rotors. With these replaced the car again runs smooth. The parts cost me less than £200 and I fitted them myself in less than an hour. Next job is refurbishing the throttle motors. A relatively simple job with lots of guides available on line. However if I were to ask my BMW dealer to do this they would just replace them at a cost of £1800-£2000. If you're not prepared to do your homework then yes, these cars can seem expensive money pits but in reality most owners find much easier and cost effective solutions to the relatively few issues the V12 has. With regular servicing they can easily do 250-300k if not more.

[Baggio850]

Just to add, I would rarely trust a BMW tech to work on this car. The majority would suggest replacing part after expensive part rather than actually 'fix' anything. The DK throttle motors being a good example.

[se15679874]

A true classic.

[Ti335]

Amazing car, especially for it's time. Too bad that BMW will likely never again make a car that is nearly as good-looking.

[BRAISKI]

It would be really nice for BMW to have a super car to compete with the R8 and SLS. Perhaps they will make the M8 and see the light of day! Which the E31 M prob never did!