m120s666

I declare the m120 the finest v12 ever built by mercedes it may not be the most powerful by any means, but imagine being the fool that spends 230k on a sedan with an m137 and a couple big *** turbos on it minus the cylinder deactivation but still with the same finicky reliability call it the m275/m277 to distract from the fact that you have just spent enough money to buy a house on a 3 valve/ cylinder engine thats less reliable than a smooth beautiful m120 that naturally aspirated makes 390hp/420tq vs m137 (5.8 vs 6.0) 367hp/390tq sure its lighter and the m137 s/cl does 0-60 in 5.4 vs 6 in the m120 but as your stranded roadside the unstoppable whirr of a magic carpet ride m120 shoots by you cruising at 130 with no care in the world screw your coil packs and your cheap daimler chrysler era cost cutting garbage a w140 m120 is no race car but its the better car for fractions of the cost! a w220 is a mechanics bread and butter!

steelers6nj

In your opinion is there any way to make that engine last for 500,000 miles or more and how hard would it be to completely blow that type of engine????? Thanks in advance..

m120s666

Well 500k Miles might be a little stretch for most gas cars without a rebuild regardless of fine craftsmanship and reliability , Now a diesel dodge cummins probably could do that. I would think that somewhere in all those miles you would most likely require a rebuild. The transmission would basically without a doubt need to be rebuilt though. I have read on these forums about people seeing a running m120 s600 with 366k miles, recently I saw a m119 s420 with 311k running well with only a rebuilt transmission. These engines are coated with nikasil so the cylinder walls are glass like and they are very under stressed in their stock form personally I think the m120 minus the infamous biodegradable wiring harness issues is the height of reliability in high performance flagships and if you use mobil 1 and change the oil around every 5k miles you should be good. The electrical components of the w140's and r129's are not cheap to repair however but I'm specifically talking about this work of art engine, You can blow the head gasket on any vehicle if you neglect the cooling systems and stuff that all engines are susceptible to but if properly maintained this is a pretty difficult engine to blow that being said I think all engines can.

KNBS550

i concur. The M120 is an engineering work of art. I miss driving that engine. I wish you the best in maintaining your W140's engine so that it has many more tens of thousands of kilometers or miles to go.