Ambitious W221 Project
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Junior Member
Joined: Aug 2022
Posts: 26
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‘12 S550
Ambitious W221 Project
Has anyone ever successfully installed an M273 in a 2012 S550 4M and have it work well? Or heard of anyone who has? Would appreciate some pointers on whether it is doable or if you know someone who may know how to get this done. My factory M278 has gone to **** with coolant and oil mixing, as well as a bunch of other problems, and I don't want to get rid of the car since I wouldn't get anything for it--and want to install an M273 in it somehow. Is it a pipedream or is it doable?
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S500
anything is possible but the likelihood of it fitting easily and then working out how to get the car to run OK will be horrible
software will be the difficult bit assuming you can mate the engine and box OK - and no one will want to help / let alone buy it afterwards - you'll spend more money than buying a new car - and the time will be hundreds of hours of hell
software will be the difficult bit assuming you can mate the engine and box OK - and no one will want to help / let alone buy it afterwards - you'll spend more money than buying a new car - and the time will be hundreds of hours of hell
Thread Starter
Junior Member
Joined: Aug 2022
Posts: 26
Likes: 1
‘12 S550
I would've preferred to, but the issue with replacing it with a used M278 engine is that I'd have no idea how long the replacement would last as it is susceptible to all the same M278 failure points, and end up with the same problems in one year. With an M273, I could get a fully remanufactured from engine from Metric Motors or something, but I haven't come across anyone who's been remanufacturing M278s such that its good as new and will last 7-10 more years. That's my thought process at least.
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Joined: Dec 2006
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From: Atlanta
W222 AMG S63
I would've preferred to, but the issue with replacing it with a used M278 engine is that I'd have no idea how long the replacement would last as it is susceptible to all the same M278 failure points, and end up with the same problems in one year. With an M273, I could get a fully remanufactured from engine from Metric Motors or something, but I haven't come across anyone who's been remanufacturing M278s such that its good as new and will last 7-10 more years. That's my thought process at least.
You are operating under the assumption that the M273 is a perfect engine and a replacement M278 is guaranteed to quickly fail.
Why not simply take your money and buy a car with a M273 in it?
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