Look at Deplore footnote
I DIY everything, so prefer inline engines as much easier to work on.
But new technology puts V on new 6-cylinders so if you want better HP combined with better economy - you don't have much choice.
Even 280 is V6
It's largely preference. I love love love the M104 engine... I love it so much that I have my own custom plate that says "M104"... Anyway.
Preferences, really. M112 is more efficient than M104 in gas consumption, but M104 is more pleasurable and on paper, ever so slightly stronger. At full throttle, M104 sounds beautiful, whereas M112 sounds like a neutered chicken pretending to be a v8. Ymmv. The i6 is a lot smoother than v6.
The previous post was typed on my phone, wanted to say more. Now I'm on my laptop....
Downsides?
M104 will need a headgasket done at some point or another. The original headgasket was badly designed, so it would either leak oil or coolant. Once done, it's "usually" a permanent fix, assuming you use MB headgasket. If you DIY, can do everything under $600. If you don't, then make sure the HG has been done before you buy.
Just like M112, it also has some common source of oil leak, and it is also equally easy/cheap to fix.
Spark plug is every 30k instead of 100k on M112, but spark plugs are cheaper (something like $2 each vs $5-6 each for M112) and there's fewer, so it all balances out.
M112 downside:
M112 has the rear main seal leak, which needs the transmission out to be fixed. It also has a bunch of common oil leak spots, including valve cover gasket. All easy to do if DIY.
Depending on the year of the car/engine, might need harmonic balancer done.
Idler pulley needs periodically replaced, but is otherwise solid.
Spark plugs replacement are way much faster/easier on the M104 but it is not that hard on the M112, just more time consuming due to 12 plugs vs 6.
I prefer the M112 as it is more fuel efficient and feels more torquey although as Deplore mentioned on paper the M104 should be stronger.
Also I like the more room in front of M112 since it does not have a fan, the M104 does not have that much room even on the W140 chassis.
Well, hate to spoil your parade guys, but more topics on the subject on forum can only indicate more troubles with it.
Why do we have so little "support" on diesels?
Not necessarily. Support also covers regular maintenance items too. The OP did not ask about the diesels, just M104, and the M112. so it is a mute point.
I have a diesel now in my w124, too much blowby I think that's why I'm moving on. Also considering a 2000 e430. So that brings the list to a 97 e320, a 97 e420, 98 e320, and a 2000 e430. Looking for the most reliable out of the bunch.
Just wondering why are you more interested in the pre-facelift cars more? I ask because you mentioned the 97 and 98 e320 and the 97 e420. If reliability is what you are after then the 2000-2002 cars is what you want.
I had 4 of prelifted W210 and all have been very good cars.
Biggest expense was CV joint on 4M and radiator on diesel.
Other than that - just pilot bushing and ATF + normal stuff.
I think you should also look into other things apart from the engine . All these cars suffer from electrical problems, and some more than the other. Get a car with at least two working and in good condition keys. Key / ESL / EIS failures are high cost items. Transmission wise, get a 2000+ car, because of some improvements, and avoid high repair costs. IMO, the A/C issues like the duovalve are less costly to fix in E320.
From diagnosis point of view, again 2000+ cars provide better OBD2 support for the scanners.
Go to the dealer and give your ownership docs, VIN#, etc. , and let them swipe your credit card for about $300, then within few days, you get a shiny brand new key .
Hah. Dealer or specialist indy only. No one can program keys willy nilly.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Mercedes-Benz Forum
7.6M posts
693.6K members
Since 1999
BenzWorld.org forum is one of the largest Mercedes-Benz owner websites offering the most comprehensive collection of Mercedes-Benz information anywhere in the world. The site includes MB Forums, News, Galleries, Publications, Classifieds, Events and much more!