Benz Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
Hello to all! I've admired the W140 chassis for some time, and finally it's time to give them some serious consideration.

I've owned a 1989 1/2 Jaguar XJS - while not exactly cheap to run, it is feasible to use as a daily driver, as the weak points on this vehicle are well documented. As long as you stay ahead of the curve on the repairs, no problem. Also nowhere near $10k per year for upkeep.

Scouring the internet, I find that $10k per year for upkeep on a V12 W140 Mercedes sounds like a rather steep figure. After all, these were the flagship, and as I understand it are quite reliable.

What I haven't seen is any discussion (other than the timing chain) of known weak points. I understand that low production #s and the owners financial ability to make repairs as necessary probably keep a lot of talk out of internet fora, but if anyone could shed some light on what to look for, and what your experiences have been, I would appreciate it.

I'm most interested in the 1992 to 1997 range.

Cheers
 

·
Registered
Joined
·
678 Posts
The engine its self is pretty stout. But there are so many things that can commonly go wrong with them. All of which are very pricey. Just to mention a few, front upper covers tend to leak on them (pricey). The insulation on the engine harness starts cracking after a few years (pricey). They're notorious for overheating problems, which in many cases can be a problem when there's absolutely nothing wrong with the car. Not to mention if you ever need to replace one of your throttle actuators, they're a good 3-4 grand a piece! I'd say, yeah, they're pretty damn pricey to own.
 

·
Registered
Joined
·
1,467 Posts
I think if you only spend 10k/year keeping a 12 cylinder w140 running, you're doing very well. They drive great (although they are no faster than the 5 liter cars), very smooth, nicer interior and they sound very cool when the gear reduction starter kicks in. One just needs to make the decision that it is worth it for them to spend three times what it takes to keep a 5 liter car running. Don't get me wrong, I do love the cars, I just see them as a finacially sound decision.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #4
Thanks for the replies...

Wow, I thought that the era of fussy 12 cylinders pretty much died with the XJS (an ancient design that was never really suited for passenger car duty). The 600 series, the BMW 750 & 850, I thought would provide near Honda levels of reliability.

I live in the Houston area, and although I haven't checked into it yet, I would imagine that independent service centers would be able to maintain these vehicles for significantly less than a dealer. Is this true? How about aftermarket parts availability (maintenance, not performance bits)?
 

·
Registered
Joined
·
1,467 Posts
I would never for any reason use aftermarket maintenance parts on an MB, especially one as fickle as this. The BMW's were even worse. The new generation is definitely better, but still has their share of issues (with both brands).

When you think about it, the m120 V12 is actually only two m104 inline six cylinders that share a common crank. They have two m104 ME modules, two Maf sensors and two m16 throttle actuators. There is literally nothing the two sides share but the crank. It is only by sheer chance that the two run together.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #6
Okay, so it would appear that the engine itself is durable, and that most of the maintenance cost stems from accessory/electronics failure. Given the relatively close levels of trim, how does this make the 500, 400, or 300 series much cheaper to maintain (besides fuel consumption)?
 

·
Registered
Joined
·
1,467 Posts
The componentry for the lower levels of trim was used in many other models in the family. As such, more parts were made, r&d costs were spread out over more vehicles and therefore they are less expensive. The 600 has a lot of unique componentry on it as well as twice the number of engine parts that one would find on the six cylinder model; oftentimes engine repairs will run exactly twice what they would on an inline six model.
 
1 - 7 of 7 Posts
Top