The Complete M271 Engine thread. ( Revised and Updated )

[grober]

M271 breather hose full install - MBWorld.org Forums

 

[nicolson]

Hello, thank you but did you read the last paragraph? I don't want to remove the supercharger and find out that it didn't help...

 

[grober]

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and
Worn Breather hoses w203 ?
QYUITE

this introduction to the m271 evo may help with a couple diagrams of the crankcase ventilation systems but it does refer to the later turbocharged version.
http://autocats.ws/manual/sdmedia/mediadb/mb_Acrobat/einf/m271/2009_05_001_001_en.pdf.

My guess would be you might be getting a small airleak into the inlet leaning out the mixture. One way to test this [ without removing the kompressor] would be to disconnect the breather pipe leaving it open to air where it joins the inlet temporarily and block off the connection where it enters the inlet temporarily . If the idle smooths out then it would point to a leak from those hoses mentioned above?? Evidently its the long upper one that goes most often.

 

[nicolson]

Hello, thank you, I will try to block the inlet. Like i said earlier, I checked the upper pipe and it seems to be ok. It was replaced in 2012. I'm not sure about the hidden two hoses, though.

 

[Wolfmann101]

Hi all,

Newbie here looking at buying an slk second hand for weekend car, between 2004-2008. Want to get a a 271 version but have been hot on my research and seen multiple thread and websites saying cam sprocket and timing chain issues, how common is the issue? Also I’ve seen somewhere that at some point in engine numbers they rectified the problem? Is this true? Some guidance would be helpful even though I’m sure it’s been answered a thousand times? Looking for one with around 70k on. Thanks!

 

[markjay]

1. The issue affects all M271 engines, up to when they were retired in 2014.

2. If buying a car equipped with the M271 engine:

a. Buy a low mileage car (sub-80k miles) with FSH

or

b. Buy a car with proven (bill) timing gear upgrade

or

c. Buy a car after a mechanic removed the camshaft cover and inspected the timing gear

or

d. Buy a car and set aside the money for upgrading the timing gear asap

 

[markjay]

Re how common the issue is... obviously it's a statistical risk that does not affect each and every engine, but its quite common, unfortunately.

And there's a very real risk that if it occures, then in a worst case scenario the reapir cost will in fact write-off a 2004-2008 car.

 

[Richardalexanderbennett]

Need info on replacing a 2004 271.941 engine in a w211 (180k) with a 2010 271.954 engine including gearbox as my engine and gearbox are both knackered. would this be a straight swap or would I need to change other parts?

 

[grober]

There were numerous changes to the M271 over its lifetime later engines were turbocharged rather than the supercharged [kompressor]earlier type. Because by this time much of the engine electronics [ ecu] is integrated into the rest of the cars electronics engine swaps are difficult. Another m271 engine/gearbox will fit [ possibly with minor mods] but getting them to talk to the rest of the cars electronics may prove problematic
Mercedes-Benz M271 engine - Wikipedia

 

[Richardalexanderbennett]

The 271.954 is supercharged and fitted to e class from 2006-2009 it’s about 20 more hp but according to the seller basically the same engine. will this still have compatibility issues with a 2004 e class?

 

[grober]

The only person that can answer that with any certainty is someone who has done such a swap. Mercedes, inline with other manufacturers, make detailed modifications/improvements to their powerplants over the years of production making compatibility of powerplants from different years difficult to predict.

 

[Richardalexanderbennett]

Thanks for the info. I’ve now decided to get an exact match engine and gearbox (same year same model) what other parts would need swapping over other than the engine/gearbox. Thanks

 

[Remmoc]

This timing chain issue is making me want to sell the car . Like a buffoon I bought it without doing enough research . Its running fine and a recent star test only picked up a crank sensor out of range ( i knew this already ) and the alarm module inoperative ( didnt know this at all )
Engine when stood over it ticking over sound quiet and smooth even from initially start up after a day doing nothing . however if i stick my ear on the cam chain plastic cover it all sounds rather rattly .
My question is ---
Is that normal
Should I worry
Ive no money left after a few unexpected house issues ( central heating boiler ) so i cant realistically do much at present .
Advise would be most welcome
Thanks

 

[markjay]

If the chain is on it's way out, you'll hear the rattle without putting your ear to the timing cover.... I heard this noise once and the description 'bag of nails' is accurate.

But if you do hear a rattle, switch off the engine immediately.

 

[Remmoc]

If the chain is on it's way out, you'll hear the rattle without putting your ear to the timing cover.... I heard this noise once and the description 'bag of nails' is accurate.

But if you do hear a rattle, switch off the engine immediately.

Thanks , il keep my ear open just in case , would the star test pick anything up such as cam timing

 

[grober]

Put your ear to any engine-recommended technique is to use a solid object like a large screwdriver- tip on the engine and handle to your ear [taking care not to get caught in any moving parts like the fan or polyV belt or touch any ignition HT ] and you will hear a startling variety of metal on metal sounds- this is normal- the noises to worry about are ones you can hear without opening the bonnet!

 

[Richardalexanderbennett]

How many hours does it take a garage to replace the timing chain? do you need to replace the sprockets if you are changing as a precaution and there is no problem with the engine? Also is it easier to replace the chain with the engine out (mines out at present)

 

[grober]

If the engine is out already [ half the battle is access] subject to detailed component inspection/engine mileage/overall condition it would make sense to replace all the timing gear -chain- gears-guides- tensioners while its out.

 

[Bobclive2]

This is an interesting read, it appears the M271 kompressor will just let go, if the EML comes on that`s it, the CGI version according to the article below will be repairable as warning is given by rattle at startup and EML on dash.

Part I - Mercedes Benz c-class timing chain (W203-W204) C180/C200/C250 - C&S Service Centre
Part II - Mercedes Benz C-class timing chain rattle (W203-W204) C180/C200/C250 - C&S Service Centre

 

[Remmoc]

This is an interesting read, it appears the M271 kompressor will just let go, if the EML comes on that`s it, the CGI version according to the article below will be repairable as warning is given by rattle at startup and EML on dash.

Part I - Mercedes Benz c-class timing chain (W203-W204) C180/C200/C250 - C&S Service Centre
Part II - Mercedes Benz C-class timing chain rattle (W203-W204) C180/C200/C250 - C&S Service Centre

Thats not good , one day it runs , the next it and the car is scrap