I'm considering an E550 or ML550 for my wife.

I initially read horror stories about the M273 and M272 given it's balance shaft and/or sprocket issue, but it seems they fixed this issue from 2009 forward.

From 2009 and on, it seems this engine is pretty damn reliable and only has a few common problems that are not catastrophic.

I REALLY like that the engine is NOT direct injection as I hate the issues direct injection can cause (expensive to repair/diagnosis, expensive parts (injectors and fuel pump), carbon build up, etc)

How do you all like your 2009 + M273 or M272?

 

Well it has the same intake manifold issue as the M272. You should change out the oil separator and breather cover to stop oil from entering the intake. The intake flaps get gummed up and then the levers break and then you have to replace the intake, if you just replace the lever, the flaps continue to get gummed up and eventually the flaps will break off and fall into the engine causing damage. Of course the usual stuff applies, always motor mounts no matter the engine, M272/M273 thermostat, pulleys/tensioner, oil cooler gaskets go all the time but those are more maintenance items.

 

242K on the M273 in my 08 GL550 and it still barely uses any oil. All of the rotating items on the front of the engine except for the water pump for some reason have been replaced, but that's expected given the mileage. Mine had a fluke coolant leak in the head early on that was fixed under warranty, but it isn't a common issue. If you're mechanically inclined, it is easy to work on and parts prices from third parties (and sometimes MB) are reasonable.

I'm in the market for a M273 E550, so I'm a fan. Great engine and underrated IMO. Very smooth and makes power throughout the powerband.

 

I don't know why you guys aren't jumping on the one listed in the forsale section. Forum member and has a good amount of options. Basically priced at full retail but it's not easy to find one that well loaded. I'd get it myself if I weren't holding out for a 2016+ or an E450.

https://mbworld.org/forums/market/848190

 

That's funny i've literally changed everything you mentioned and getting ready to do the intake manifold next as I can hear it whistling. Still never had a check engine light on in the car and it has been very reliable. Only time I stopped on me is when the alternator failed. Edit.. Actually haven't changed the oil seperator and breather cover.

 

There's a reason FCPEuro sells it as a kit. I changed the intake on mine, had a pending code for the intake but it hadn't triggered CEL light yet but the lever was hard to move. I don't think you really need the hoses unless they're really filled with oil or the oil separator for the right side, it's usually the left side that goes. You also don't need to do the plugs if they're not leaking but you should check them as they also frequently leak. The oil separator on the left is reverse threaded so you turn the opposite way to loosen/tighten.

https://www.fcpeuro.com/products/mer...kit-oem-515810

 

Just to be clear are you recommending to change the oil seperator while changing the intake? Or is it something I can come back and do later? Was it hard to change the intake manifold? I am deciding whether I want to do it myself or pay $330 for an Indy to do it. I don’t have any cel or code for the intake but I have a whistle noise and also the engine shakes I think because it is leaking intermittent or running lean.

 

Yes. If you haven't changed it in a while, my hoses were coated with oil which is probably how the oil got into the intake to gum up the flaps. You can try moving the lever by hand if you can reach it and see how easily it moves. Mine was stiff and when moved by hand afterwards did not bounce back. The new one moved easily by hand and bounced back easily. I scanned it with a code reader that could do MB specific codes and it was a pending code, hadn't set a CEL yet, but it was only a matter of time. There are several videos on how to replace the intake. It's a somewhat long process. Pretty straight forward though, just takes a lot of time to remove everything. Make sure the gaskets you get are in good condition, one of mine was somewhat bent a little and didn't easily stay on and a little tricky to make sure the intake goes on top of the gaskets without sliding off. Got mine from FCPEuro, at least I'll have a lifetime warranty if it ever goes again.

 

oh ok I actually do recall changing the crankcase breather as it was leaking a while back. Which intake manifold did you get the oem pierberg? I have seen an off brand and was considering it but not sure on this part if I should just stick with oem. One thing I noticed on the aftermarket is they come preinstalled with the aluminum air flap lever thing. Which they say commonly goes bad on the oem because they are made of plastic. Also they say it can be cause for sticking flaps etc.

 

They are made of plastic for a reason, the lever breaks when the flaps get gummed up. With a metal one, I think the flaps just keep moving and eventually break off and fall into the engine causing engine damage. Which off brand are you looking at? I only looked at a rebuilt one which had bad reviews and it was only a few hundred cheaper than the OEM Pierburg which I bought from FCPEuro. At least that was brand new and had a lifetime warranty. The rebuilt one only had a one year warranty. Not really something you want to do again. I think the cause for the sticking flap is probably more from the bad oil separator allowing oil into the intake instead of just fumes which is why the hoses were coated with oil.

 

Interesting... I had never thought about it like that. They seem to have countless companies now making these aluminum "repair kits" to replace only the lever when they go out and not even change the manifold. Here is a link to the arm as well as the 3rd party intake manifold made by MITZONE. ... for some reason I can't link to anything within amazon i think it just takes you to the homepage..

 

No reviews on that 3rd party intake, no warranty info and made in China. I'd pass. The lever is a short term fix, will probably get you a few months/years before the flap breaks off. Only worth it if you're thinking of dumping the car in a few months. Basically on my old intake, the lever was very hard to move. I could see it breaking off at some point once the flaps got really stuck. I would think the metal wouldn't break and just force the flaps and then the flaps would break instead of the lever. Except the broken flaps go into your engine.

 

Yea I was a bit iffy about it coming from china and having no reviews but the price was the main selling point at $350. I haven't inspected my lever yet but i'm betting that it is the plastic one that came with the car in 2010 it is now at 120k+ miles. I have heard that the plastic lever breaking can be an issue though even at very low miles. I wonder if maybe this is more of a problem in colder climates or if there are other factors. I would hate to install a brand new intake to have the lever go bad on me. Is it likely that a flap would actually break off? Wouldn't they be less likely to stick if you have a metallic lever vs a plastic one? Also I looked at the manifold they make for the m272 which I guess has been outa bit longer it does seem to have some good reviews.

 

Search the old threads, seems like the flap problem happens in the 80-140k range. I think it's probably the oil separator going bad and oil getting on the flaps and getting baked by the engine heat. So I think it's the oil causing the flaps to stick, not the lever. That's why I'd change the oil separator. There are other threads about the flaps breaking off but that seem to take a while after the lever was replaced which is why you can get away with just replacing the lever for a little while. If you want to drive it for another 80-140k, I'd replace the intake with a new OEM one. Who knows how long one made in China will really last and who knows what the warranty is? Regardless, I'd hate to do it twice.

 

Think of the plastic lever as a "mechanical fuse": if the resistance I have to move is too high --> sacrifice me for the greater good of the engine.

 

That's the M278 (4.6tt), not the M273. The E550 has the M278 in 2012+

 

Yes I know that. It's probably one of the best E550's out there. Doesn't have the issues of the M273 and it's the last year for the E550, after that, only E400/E450. You'd have to go to an E53 to get more hp, even the E43 didn't have as much hp. Also 2014 was the face lifted model and had more standard options and items like collision prevention.

 

Absolutely agree, best in my book. I'm actually looking to get into one this winter. Plenty of tuning capability (500whp/600wtq stage 2 ). In my opinion, it's a car with an AMG motor, without the AMG price. I'm split between the coupe and the sedan. Sedan would be an AWD beast, but the coupe is only 3700lb (more zoom )

 

I'd rather have the horsepower of the M278, but they seem to have more significant problems than the M273 if you avoid the earliest engines with the timing chain idler issue. Bore scoring and valve guides/seats are big $ problems.

 

 

After a bit of research, cylinder scoring on the M273 is not unheard of either.

I was debating between a 2011 E550 coupe (last year of the M273 in that car) and a 2016/2017 E550 coupe (last year of the M278), and the more I read, the more I'm inclined to run the opposite direction and find a different brand altogether lol. Which is a real bummer, because I really like the E coupes. I'm just not willing to potentially pay thousands of dollars and go through a huge hassle to have it repaired (which seems to be a very realistic possibility).

 

An indie Mercedes-Benz mechanic told me that I could rely on M273 engine as much as I would rely on M278. However, he also unsparingly stated some weak points of the engine as well as you said and told me to use an engine of that meets 229.51 Mercedes Benz specs

 

From what I have read in these forums, it seems both engines M273 and M278 have their issues. Just like any human-made device. Keep in mind the more complex the engine, i.e. turbo, the more failure points to repair in the future.

What I am missing is the separation of M278 failures between before and after the chain tensioner/check valve statistics. That is, Have those engines that do not require the "adjustment/service recall" shown any camshaft adjusters issues after 100K+ miles? I think that is the nail in the coffin to make a decision.

Perhaps in my 20's/30's I will take turbo-engines just because of the extra power and easy-tune capabilities, but nearing retirement the picture is different. That is, once you are in the 300+HP, a few more HP will not make a difference unless you also have extra money for the tickets/insurance. Then, it comes down to how much it will cost to fix the known issue when it comes up.

M273: intake manifold + crankcase breather + hoses < $1000 parts + @400 labor or 4hr DIY..+ Worse case would be worn idle gears.
M278: camshaft adjusters + "camshafts?" + plastic conduits for turbos: $800 x 4 + $800 x 4 + @2000 labor or a few days DIY + turbos after @100K+ miles (design specs)

That is regardless of cylinder scoring, carbon build-up, oil harness migration, and typical wear items.

 

You have to take these reports with a grain of salt. It's not at all common on the E class as mentioned in this forum. Odds of it actually happening to you would be low. There's still many people out there driving 2006 E class cars with the bad balance shaft and it still hasn't gone on them yet. Same as the conductor plate going bad or transaxle/differential. It happens but it's not that common. There are other risks in other brands. If you can't afford the thousands, then maybe you should look at another brand or look at getting a one or two year warranty, at least you'll get to enjoy it for a year or two before you'd have to pay for it out of pocket. If you listen to too many people on these forums, they'll always tell you not to own a Mercedes out of warranty. But I have two of them and they were bought bought used without any warranties. I just have a reasonable priced indy and these forums are great for finding out good info on how to do the repairs inexpensively. It's a roll of the dice on my part, but so far, no real crazy expenses.

Did you get the number wrong? For gas engines, 229.5 is still preferred, 229.51/229.52 is more for diesels but you can still use them in gas engines.

I replaced the intake on my M272 and it was a tad under $1000. The Pierburg intake with o-rings and gaskets was a tad over $650 and then I got the breather kit and got my indy mechanic to do it for $200 as someone on here claimed they got a Mercedes dealer to do it for $250 which I found hard to believe but I guess if they do them all the time, maybe he got a break on the price/labor. Took him the full 4+ hours to do it as there's a lot to take apart and put back together although it's all pretty straightforward, the youtube videos on how to do can be over a half hour and that's sped up.

 

Yeah, I get what you're saying for sure. Sometimes infrequent issues get blown out of proportion. Thankfully, affordability of repairs isn't an issue; I buy used cars by choice, not by necessity, and I know a used Mercedes is probably to require a bit more care than a Toyota. However, avoidable hassles and judicious use of hard-earned money are certainly issues to consider, and I don't consider time-consuming and high 4-figure repairs very palatable for a sub-$35k car. I have an CLK550 (M273) now, and so far so good. But it does have a very slight rough idle at times (it's usually not even perceptible), and my experienced indy (former Mercedes dealer mechanic) was unable to pinpoint what the issue is/was. It's been like that for the whole time I've owned it though (25K miles or so, now at 85K), and it hasn't really gotten better or worse, so who knows. But I wouldn't at all be surprised if it has a scored cylinder wall or eight. The M273 reportedly uses the same Silitec cylinder wall coating as the M278, which isn't known for its longevity.

Also, not sure if you've seen any teardowns of the M278, but I've seen at least two or three, and each one had scored cylinder walls. Conversely, I just watched a teardown of a blown high mileage Toyota V8 (valve broke off from apparent neglect), and the cylinder walls were perfect. I know this is pretty anecdotal, but combined with all the other chatter about bore scoring on the M278, it would seem unwise to ignore this issue altogether. Based on my research, there is no way I'd own an M278 car past 100K miles. Up until a few days ago, I was dead set on a 2017 E550 coupe in the near future. Now, not so much lol.