Hey Everyone,

I'm a long time reader of these forums however this is my first post!

Engine is M271 (E200 Kompressor) and has 186,000 KM on it.

Engine running video:



Around 5000-10000 KM ago I started to get few OBD errors related to engine timing. Initially deleting the errors made them go away for few weeks at a time, recently however they come back after a few drives.

Errors frequently showing up:
P0020 Camshaft position actuator circuit (Bank2)
P2054 Reductant Injector Circuit Low bank1 Unit2

Rarely also seeing:
P0365 Camshaft Position Sensor "B" Circuit (Bank 1)
P2054
P200B

Engine performance is OK (no apparent power loss). I checked the Camshaft actuator connectors, they seem to have dirt and oil residue although the oil-stop cables have already been fitted by a previous owner. I cleaned them up with contact cleaner (also cleaned up the sensor cables), however errors are still showing up.

I would like to double check the timing, for peace of mind since there is a slight rattling sound to the engine (not new), it is however persistent and I can hear nothing special upon engine startup.

I got a timing gun and connected it to trigger on the 1st spark plug (the one farthest away from the bumper, right?) and aimed it at the crank pulley.

Results:

Idle (800 RPM or so): about 5 degrees to the right of OT [viewed from bumper]
~ 1100 RPM: 25 degrees to the right of OT
~ 2000 RPM: close to OT, about 5-10 degrees to the right.

The big question: Do I have a problem with the timing chain, or with timing at all? What is the best way to check? Is the timing gun conclusive?

I am trying to verify timing without having to take lots of things apart (valve cover etc...) if possible. If there is no other way please advise.

Thanks!

 

Visit the w203 section and research the m271 and codes thrown when you have timing chain issues. They are known to stretch and then usually snap causing very expensive repairs.
Upload us a cold start video.

 

Remember that the camshaft actuator magnets & connectors are on the front of the engine. The camshaft position sensors are further back on the head. You might need a new CPS. You need to make sure that the pigtales & engine harness are free of oil all the way down to the O2 sensor plugs.

I don't like that rattle. If it was my car I would immediately pull a new timing chain & replace the use once tensioner element. While I had the cam cover off I would carefully inspect the camshaft actuators.

That rattle is either a stretched timing chain or a damaged camshaft actuator, or both.

The spurious codes you are getting lead me to believe both faults.

Good luck!

 

Thanks Glyn for the feedback!

Forgot to mention that due to regrettable reasons, the car was driven around 18,000 KM without oil change. Maybe that hints at something?

What about the stroboscope measurements? I read in the MB docs that 20 degrees is about one tooth. The measurement at 2000 RPM was exactly 20 degrees off that of idling. Can we conclude that the chain skipped one tooth?

How would you inspect the camshaft actuator?

I am doing my research now in order to open the valve cover up soon. I would like to have all parts with me though, to minimize the time it takes to get her back up and running.


Regards

 

I don't think the chain has skipped a tooth. The chain can stretch that far though. We also need to be careful not to confuse cam timing with ignition timing. Anyway, you can check the static cam timing with the cambox cover off. Don't delay chain replacement. We don't want to end up with bent valves.

You need to check the cam adjusters for burring & play/rattle. Also use an engine stethescope to listen to them before the cambox cover is removed. You need to check the cam sprockets for wear. A worn chain can wear them out of spec.

I don't think one 18K oilchange would affect this. The standard drain interval was 15K on the M271.

Good luck.

 

Update for the sake of history, hopefully someone benefits from this.

I ended up changing the two camshaft position sensors (one intake and one exhaust). Guess what? It worked. After clearing the errors they never came back.

BOSCH 0 232 103 086
+
MERCEDES-BENZ: 272 905 01 43/ 272 905 00 43 (was a FEBI part)

Regards

 

HI thanks for the good information I have the same problem in my car can you til me watt you Chang in the Exhaust AR you Chang exhaust gas temperature sensor
or exhaust o2 sensor or all ??


Regards