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Unfortunately I ended up putting a 3.5L m272 from a GLK350 and its was bolt up and ran with the C300 ECU. I still switched the engine type in Xentry/DAS to 3.5L and its been great since.
As for the m273 swap, I've read through a lot of E550 and S550 owners having issue with the front yoke coming out of the transfer case snapping. The newer 4matic AMG's appear to have a similar 4matic design but don't appear to suffer from the same issue.
That splined shaft is very thin and I'm not sure how well it can hold up with the torque of a v8 if you drive the car hard a lot.
First off, I just want to say coming from experience as an indie MB tech, you are guys over complicating it. Quit it. In hindsight, it is way easier than you think. Just relax.
Motor mounts are a little broken? Huh, I wonder why?!
I don't have too many pictures or videos of the engine bay, some things got very interesting very quickly, and needed immediate modifications or relocations.
If the item/topic was not mentioned, it's probably stock/unchanged.
Keep in mind, I have full access to dealer level Xenry crap, as well as Abrites Mercedes stuff, ALL at my disposal. They are mine, saved my money, and bought them.
I have SEVERAL pictures of a friend's 2011 E550 4Matic, and if you were to cut off everything forward from the crash bar. It's identical. You can't tell the difference.
Here are the details for anyone wanting to do this yourself.
Body car: 2009 C300 4-Matic 155000 miles
Donor car: 2011 E550 4-Matic 60000 miles
The very first thing I did was fix what was already wrong with the car. The transfer case was leaking, oil change, thermostat, oh wait that's it. Then once that was done, I bought the motor from one of those pull-apart guys on eBay. $2k. Came with everything. Coils, plugs, intake, idlers, harness, but not A/C comp/Alternator/ECU.
Drop the motor in and saw what fit, and what didn't fit.
ALMOST everything lined up. Exhaust, harness, fuel line, axles, diff, oil pan, firewall were plug n' play. There were a few funky parts though.
NOTE: The distance FROM the firewall to the back of the heads is EXACTLY the same as the V6. With that being said, The oil pan and axles, bell housing, converter, heater core, and everything else on the back end, fit in absolutely no problem. The V8 moves the additional cylinders FOWARD in the engine bay. The excess room up front is taken up by the two extra cylinders.
SLIGHT Issues:
1. The power steering cooler, which was initially bolted to the upper oil pan, has been relocated to hiding underneath the oil pan, above the subframe, it's literally just resting there. Yes, it was put there for a reason, I live in a coldish climate, it's metal, and not touching any sharp things, not able to snag on-road debris, so I'm not too worried about it. Not too much I can do about it either because there is no room.
2. A/C low-pressure line bracket was unbolted from the body near the brake booster/front sam and the aluminum line was GENTLY molded to its new location. The engine moved forward. The original line was threaded in between the ABR and body perfectly centered. Now with the V8, the A/C comp is moved forward and I need the line that isn't there. Bend it! carefully!
3.The original upper hot side main coolant hose was pinched too tightly against the fan shroud, NOT the fan blades. This was how I drove the car for the first week or so. Left the coolant SLIGHTLY lower than where it so-post to be and left the coolant cap a little loose so I would build too much pressure. I might have blown this hose off twice before I narrowed down the reason why it was blowing off. Luckily I was joyriding it 1000 feet from my house and 1000 feet from the shop. No harm done. I had a welder friend weld me a custom water line. This line was Frankenstein from an M273 E55 A209 upper water tube and an M275 E60 W220 water tube. I cut the thermostat side from an M273 and the water outlet side from M275 and he welded them together. I should have used the M273 water outlet, M275 was too large. BUT WHY can't you just use the M273 A209 upper hose?! It was too small for the radiator fitting and the quick disconnect was 90 degrees off, so the clip won't even slide in. PLUS the engine sits too high to use that hose. The top of the aluminum water tube is PERFECTLY flush with the radiator fitting.
4. Vacuum lines. The original vacuum line on the W204 was gently heated to mold it to go on the intake manifold vacuum port, instead of the vacuum pump fitting. Drove on that for the first week or so. It's hard gooey plastic, wasn't worried about anything snapping. Already had the improved solution sitting on my toolbox. The solution was to buy 2011 E550 4matic brake booster vacuum lines, the ones behind the false firewall. The brake booster on w212 had n A212 part number. The brake booster on w204 has a A204 part number. DUH. BUT! The vacuum female fitting has the same exact location as the 2011 E550 4-Matic.
No specific info shown on this swap has been found anywhere, so sometimes you just gotta buy stuff and see if it fits. Bought vacuum lines, fed them behind the firewall, and drilled a hole in the firewall blank black plastic tab, boom.
5. ECU trouble. Went for a first start/crank, and it wouldn't crank, and had no CAN COM to VGS, no gated shifter status on the cluster. Ensured power was supplied to my 2007 CLS550 ECU. The problem was the CAN bus. 209/211/219 M.E9.7 doesn't have engine AND chassis CAN like 204/212/221 M.E. SO I grabbed used known bad w221 ECU for troubleshooting, drove it out on 4 cylinders. Solution? Buy 221 ECU. Virgined, personalized, activated. BOOM fired right up and drove it out a week later.
6. VGS. It took some learning for VGS to get used to my lead foot and torque/"boost" by gear. I did a trans service less than 500 miles ago due to a leaking transfer case sealant. It has a fault code saying that it's defective, and once in a while, it will refuse to start. DAS REFUSAL! Wait 5 minutes since the last key cycle and it's happy. The code could also be from getting torque/HP numbers it's not used to getting like it would be implausible to get 220 MAX HP then overnight get 400 HP.
7. Hot water valve. I really don't care about this one yet. I have left the A/C uncharged since the swap because I might change the low side hose out with something else. It's cold out so I'm ALWAYS using the heater. W221 ME has a code for the hot water valve. No CEL. The hot water valve on the engine I got doesn't have an electrical socket, the w212 harness doesn't have an electrical connector for it. So, it is what it is for now. My heat is hot. I'm happy. Might dig into variant coding later when It warms up outside.
8. Fan shroud gently rubs the P/S receiver. No vibrations transferred to the cabin.
9. Lower cold side rad hose "T" fitting would rub on the belt. I have broken motor mounts AND I somehow aligned the belt wrong. Solution? Motor mounts and Cable ties. Cable tied it to the trans cooler line for now. Not stressing the line out it's fine.
Why can't you use the M272 ECU on the V8? I don't know. Seriously. I was mad that I didn't drive it out on 8 so I tried everything. My Xenry won't allow you to change SCN Variant coding on W204's for some reason. Yes, I have developer mode on. You can on a w211 ME9.7 but not W204? Might just be something funky with my laptop. Changed Varient coding with Abrites though. Set it as an M273 W221. Still sounded like it only fired on like 2 cylinders while cranking. Wouldnt start. Can't see wire diagrams for an engine that never existed on a V6 ECU. So who cares.
Front SAM? Rear SAM? Central gateway? VGS? ABR? AAC? Nothing cares in the slightest about the V8. No one cares. Not a single unit. I still have no idea why.
Speed sensitive steering? I guess w221 ME97 doesn't care about it. It's not on the original pump, and the w212 harness doesn't have an electrical connector for it. No Events/Codes.
Original body/engine harness, A/C comp, Alternator, P/S pump+res.
If I wanted to I guess I could change all the Variant coding for every control module to set it as a v8 but what would I gain? Not a single event or fault code. Sooo why change it lol.
M.E and VGS are still adapting to the little monster this car is, so it's getting faster with time.
VGS gets upset when WOT at a standstill in comfort mode. Thuds back into 1st. Expected!
VGS also gets confused at WOT standard drive mode standstill. Just sits there and thinks before it authorizes the power to be delivered.
Stock fuel tune/fuel pump.
The front end is lower than it should be. I need to get some C63 springs. Rear-end slides out more than I want it to. Snow? No different from a 300.
Everything driveability on this car is like a 300. Absolute sleeper.
Some engine bay trim pieces are missing. Relax. Air snorkles whateverrrr..
Yes, I know it's dirty. There are a lot of things cosmetic wrong with this C-class. I don't care about cosmetic things.
I think it was wrecked in the front end.
I hope the power steering doesn't leak!
Customized ruined V6 E30 converter that conveniently stalls out at 3K. And recently shutters at 2k.
3.07 differentials. YES! I do spin the front tires! No, the ECU doesn't care for some reason. W221 S550 4-Matic USA has 2.65. W212 E550 4-Matic USA has 2.47.
I have absolutely no concern about power delivery from the engine to the wheels.
Differentials were probably used in w221 GUARD.
Axles were probably used in W221 or W212
Driveshafts are all W212 or W221
Transmission has a W204 case but W221 internals.
If they made a W221 550 4-Matic, N/A & TT, AND everything has a 221 part number on it, what makes you think it can't handle the power...? I'm not worried about it....
I love the 204's. People see me driving it and they could care less. But when I put my for to the floor, that's when people probably wonder wtf kind of c300 it is.
There is NO effing room between serp belt and fan. like none. Like if anything happens ill need to remove the water hose and fan, just to access the pullies.
NOTHING is rubbing where it shouldn't or doing anything it shouldn't. I could drive it cross country if the gas tank was bigger.
I got REALLY lucky with the car and all I have done to it.
11 MPG. Fuel tank lasts me 4 effing days.16 gallons worth. I love beating the crap out of this car.
NOW, I need to put in the wheel arch liner, New axle, flex disks, custom motor mounts, and some other crap.
I have an SLK230 as a slow back-up.
TOOK ME, AN 18-YEAR-OLD, ONE WEEKEND. If I can do it, so can you.
Just remember! Some guy from Colorado did the first 4-Matic conversion!!!
Kompressor_5.5, having your indie MB experience do you think the swap between m276 and m278 would be similarly as easy/difficult? (asking because the m278 does have 2 turbos mounted)
The Coupe212 E550's are the same car as the W204's but the Coupe212's are not 4matic like the W212 donors and my current W204.
722.9 Valve bodies and conductor plates are ALL nearly exactly the same. Except AMG, VGS1, MCT, etc.
I would gain nothing from swapping in a W221 specific Valvebody+Conductor plate.
I would still need to change the Variant coding in the conductor plate, to set the differentials correctly. With that being said I would have to set it as a C300 4-Matic 4 digit/numeric code, reversing what I just did. Shift firmness is also determined by that 4 digit code. If I had a Mayback/Guard sitting in front of me yeah, I look at the diff ratio and look at the 4 digit code. And just use that. No, I'm not sifting through 200 codes and seeing which one works.
It would do nothing. No point. AS OF RIGHT NOW.
No one has a list of these codes sitting around on their desktop. 7226, yes. And no one on the planet can change electrical shift/fill times on a 722.9.
You can't just swap out the valve body on a 7229. You need the valve body valve data+specific tolerances of that EXACT valve body. If you were to swap valve bodies and not conductor plates, it would shift like garbage and you may burn something up. They need to be installed as a married pair. As I said, there is not a single effing person that can extract anything besides FBS data from these conductor plates.
The only machine that can extract the valve data is the MB Xentry diagnosis. And even then, Xentry needs to see that the conductor plate is in a NEW, VIRGIN STATE.
If you cant read the conductor plate, you cant extract valve data with Xentry. If you have no valve data, you need the Conductor plate+valvebody AS A PAIR!
I could buy a 2012 E63 4matic CondPlt+VlvBdy, AND I would STILL have to set the 4 digit code back to where it was originally because I don't have a list of every code, and its diff ratio, and the chassis, and the weight, and how firm it's so posted to shift. All just because I don't have the list.
I am slowly making a long list of 722.9 diff+ VGS codes though!
Its slowly adapting to my lead foot, it is shifting WAY faster than it was when I drove it the first hundred miles.
I don't plan on screwing around with Vidmeo and seed keys and hashes and all that BS. The car is just the way I like it. I would like a manual mode, but it already upshifts when I want it to. The car is so light, with the 3.07's, VGS already does exactly what I want it to do, when I want it to. I can't argue with it like an EGS51/52, junk.
I found a sweet spot while shifting though. 2500-3200 RPM, manual/forced + upshift, Shifts so firmly that you can REALLY feel it gently thud in the seat. Nothing bad, it's just adapting to the V8. You cant tell it shifts if you were to leave it alone... No Surges/Spikes/Hesitation while shifting.
When I did the trans service 300 miles ago, oil looked okay, no metal. drained it at 43c to have some extra room for "just in case", shifting wise. Not worried about it.
2012 C300 Sport 4MATIC (current) 2006 C280 Elegance 4MATIC (sold)
Excellent write up. Would I have fewer issues with piping and keep the PS pump in the same location if I went with a 4.7 liter M273 from say an S450 or GL450. I'm seeing low kilometer M273s around where I'm living and will also see if my local indy would give it a shot. Wish you lived in Canada. .
FYI, ALL (I THINK) W204s and W205 (FOR SURE), C63's have the engine properly situated in the engine bay, none of this too tight BS like I'm going through. SO the engine is moved 1 bolt rearwards on the transmission mount bracket, and the front end is extended 1".
No, No, why would you go through all the brain damage to take out the engine, and do the swap, only to put the lamest and slowest M273 in the hole. Prolly be slower than a M272 E35 with a filter and a cheap tune.
Just no. Stop that. Put the M273 E55 in there and call it a day.
I was also concerned about the power steering pump and reservoir. Really! I was! Uhhh I kinda am but not really! C550 W209 M273 E55 W209 M273 E55 W209 M273 E55 W209 M273 E55 WATER CROSSOVER TUBE
Improvise, Adapt, Overcome.
I said to my self; well IF and I mean IF I were to install an M273 E55 W209 Thermostat, water crossover tube, and upper hose, then THEORETICALLY, I would need the P/S reservoir, Pump, and lines. See pictures!
Now if I did that, I would need to make room for my new reservoir. I would need to change the purge valve, purge filter, and all the lines, get a W204 C63 washer fluid tank neck filler tube, and all the other BS in the local area. ALL THAT WORK JUST FOR A P/S RESERVOIR! If I was even lazier, I guess I could just stash the reservoir off to the side and bend stuff. Its not worth it honestly.
If you have the whole engine out, just do the rack seals. They are right there. Not hard.
I did new rack seals, reservoir, and pump to reservoir seal.
Where else is it going to leak from? ¯\_(ツ)_/¯
Drill a hole in the side of the reservoir and put a little m8 bolt there if you're that concerned about it.
Quite a bold project you have here, congratulations! The reason your 272 ECU won't work is because it lacks the electronic components on the circuit board for the extra 2 cylinders, both injectors and coils. In theory you could solder those components in place on the board, if you could find the components and had the right soldering tools, but it's much easier to buy a used 273 ECU and wipe the old VIN as you've already done. You might want to think about clearing the transmission adaptations and re-learning the first three up and down shifts through Xentry as it directs you. However, I'm unsure if you'd run into problems as it may see too much torque to accept the adaptations.
My stock 2009 C550 4-Matic will slowly walk away from a stock 2009 S63 AMG 20-130. After 130 S63 will pass me. He was mad af!
Originally Posted by E55Greasemonkey
Quite a bold project you have here, congratulations! The reason your 272 ECU won't work is because it lacks the electronic components on the circuit board for the extra 2 cylinders, both injectors and coils. In theory you could solder those components in place on the board, if you could find the components and had the right soldering tools, but it's much easier to buy a used 273 ECU and wipe the old VIN as you've already done. You might want to think about clearing the transmission adaptations and re-learning the first three up and down shifts through Xentry as it directs you. However, I'm unsure if you'd run into problems as it may see too much torque to accept the adaptations.
Regarding the ECUs and integration with the car...does the M273 have the same redline as the M272? I think it does but not sure and one you guys may know the answer to this anyway: Let's say I put a Benz engine with a higher redline than my current 3.0 V6 in my '08 C300 (engine would be SLK350 09+ - M272.969 revs up to 7200rpms instead of 6250)...if I use the SLK ECU...will the engine redline properly after installation? Will the gauge cluster rev up to 7200rpms (even though that's past the redline on the gauge?) Wondering if some additional programming is required in the ICM or SAM. But Kompressor 5.5 if you're saying all you had to do was plug in the 273 ECU and it integrated fine...that is pretty encouraging.
No, I am not sure what the redline is on a classic M272 vs M273.
And now that you say that the SLK's have a higher redline than a classic M272, I started to think about the SLK280 I just drove.
The cluster DID look different, in some way, but I wasn't sure how. It just didn't look quite right. When I went to rev up the engine/blip the throttle, I noticed that it revved up WAYYY faster than a classic M272. And when It was done receiving fuel, for engine slow down, like when It cuts the fuel, I noticed that the engine slowed down WAYY faster than a classic M272. Another difference between the two is I THINK/FROM WHAT I HAVE SEEN some M272 350 SLK's received a MAHLE, black plastic intake manifold, versus a Pierburg, Magnesium intake manifold. I have no idea what the differences are between the two. Just something I noticed.
Now when it comes to the ECU.. I see your point about swapping out the ECU. Makes perfect sense. Just swap them out and boom your good! It seems the easiest too!
I was also thinking, what if you found a local tuner, and had them raise your RPM limit, and tune it like an SLK ECU? There is 1 local tuner guy but he's meh. So idk where you would find one. :|
As for the RPM in the cluster, I really don't think it would care. Or any control module for that matter. MAYBE VGS, idk. For fun, one time I had an older 1997 W210 M104 car, and the cluster was bad, dials broken, LCD pixilated etc. And I had these other W210 clusters laying around. One was a W210 1997 N/A OM606 cluster. I put that thing in and sure as ****, That RPM gauge JUMPED out of its paint. Went all the way up to 6200 IF it was there. Needle went off the gauges. Then I installed a W210 1999 M112 and it was fine. It didnt care. I changed the mileage and sent the little old lady on her way. She wouldnt bring her M104 up to 6200RPM anyways. She wouldnt care. To and from chruch on sundays.
look at this W221 with what i think is a bad Wheel speed sensor, going open circut/closed circut REALLY fast, so the car thinks its going 200MPH! RAPIDLY increasing mileage.
My point being, I dont think any control modules care. Youtube link:
CLK550 with no engine cover. C550 4-Matic without engine covers/air filter/TB. C300 4-Matic without engine cover. C550 4-Matic without engine covers. C550 4-Matic with main engine cover. CLK550 with main engine cover. CLK550 with engine covers.
OOPS! I just posted this in another related thread. I got some 2009 C63 Front springs and installed them on my original C300 coil-over struts. NOW the car isn't squatted in the front and the front end is about an inch higher off the ground.
Now the C550 completely looks like a C300. ABSOLUTELY NO VISUAL CUES! I don't want it to look like a gay ***, JDM riced out, lowered, cambered POS.
No, I am not sure what the redline is on a classic M272 vs M273.
And now that you say that the SLK's have a higher redline than a classic M272, I started to think about the SLK280 I just drove.
The cluster DID look different, in some way, but I wasn't sure how. It just didn't look quite right. When I went to rev up the engine/blip the throttle, I noticed that it revved up WAYYY faster than a classic M272. And when It was done receiving fuel, for engine slow down, like when It cuts the fuel, I noticed that the engine slowed down WAYY faster than a classic M272. Another difference between the two is I THINK/FROM WHAT I HAVE SEEN some M272 350 SLK's received a MAHLE, black plastic intake manifold, versus a Pierburg, Magnesium intake manifold. I have no idea what the differences are between the two. Just something I noticed.
Now when it comes to the ECU.. I see your point about swapping out the ECU. Makes perfect sense. Just swap them out and boom your good! It seems the easiest too!
I was also thinking, what if you found a local tuner, and had them raise your RPM limit, and tune it like an SLK ECU? There is 1 local tuner guy but he's meh. So idk where you would find one. :|
As for the RPM in the cluster, I really don't think it would care. Or any control module for that matter. MAYBE VGS, idk. For fun, one time I had an older 1997 W210 M104 car, and the cluster was bad, dials broken, LCD pixilated etc. And I had these other W210 clusters laying around. One was a W210 1997 N/A OM606 cluster. I put that thing in and sure as ****, That RPM gauge JUMPED out of its paint. Went all the way up to 6200 IF it was there. Needle went off the gauges. Then I installed a W210 1999 M112 and it was fine. It didnt care. I changed the mileage and sent the little old lady on her way. She wouldnt bring her M104 up to 6200RPM anyways. She wouldnt care. To and from chruch on sundays.
look at this W221 with what i think is a bad Wheel speed sensor, going open circut/closed circut REALLY fast, so the car thinks its going 200MPH! RAPIDLY increasing mileage.
My point being, I dont think any control modules care. Youtube link:
wow thanks for the info and great video for the 221.
btw i think the slk280 engine is the exact m272 as c300 but maybe it just felt different in an SLK idk. It was only the 2009-11 SLK350s that had the slightly modified 3.5 m272 (with the plastic intake you mentioned and a red strip on engine cover instead of grey) that could rev up to 7200rpms and had 302 hp. I like your 550 swap and would prefer it obviously but as i have more limited shop access/ability to modify stuff the 302hp m272 might be a cleaner swap for me.
WOW! It's so nice to talk to someone with more than 1 brain cell. I worked on like 2 SLK350's YEARS ago, and since you said it, I now remember the red engine cover. I thought it was a cheap look, so I assumed it was like an eBay kit. Same thing with the intake. It was plastic, so I thought it was an ECO budget option or something like that.
Yeah... I just looked up the specs between a 2007 SLK350 VERSUS 2009 SLK350, and holy crap is there a difference I never knew about.
258 lb-ft @ 2400 rpm
268 hp @ 6000 rpm
16/23 mpg
VERSUS
265 lb-ft @ 4900 rpm
300 hp @ 6500 rpm
18/26 mpg
**** dude just get a 2009 SLK350 ECU and throw it in!! I'd love to see a c300 cluster needle be in the red!
I'm thinking about getting one to put in my boss's car and see if there's a difference!
Are there any physical differences between the two though? Lighter balance shaft? High flow cats? Bigger chain? I have no idea!!
12-20-2020, 10:13 PM
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