C180K - Rough Idle & Missfire

[matthewnorman]

Evening all, I have been reading through here this afternoon after acquiring a C180K with some engine woes!

The car starts ok, but idles like is it a thudding great V8 wobbling and vibrating all over the place!

I have checked on the forums and beleive the issue could be linked to the cam chain and the possibility that it may have actually skipped a tooth or two!

The previous owner completed the following work while chasing the problem:
Cam sensors
Actuators
New plugs
Tested the maf
and has given up spending money on the car

I picked it up early and nursed it home the 1/2 mile to my place and have stuck my cheap diagnostic thing in which has flagged up the following

P0010
P0101
P0301
P0302
P0303
P0304
P200A
P201B
P2054

I have checked these codes out online and P0010 suggests checking the timing before going any further, and the P030 codes show a missfire detected on all 4 cylinders - so a misstimed CAM could well be the cause of this!

I am in no way a Merc guy! - This is my very first MB and I have purchased it purely to spend some time exploring the MB engineering and seeing if I can learn a few things - I am not a mechanic by trade although do a lot of my own work (including timing belts etc) - using haynes and internet for guidance with regards to setting cams, advance, retard etc....oh and the other thing is I am ususally working on 80s and 90s VAG stuff, which I appreciate will be different!

I am planning to get the cam cover off, checkout the condition of the cams and the sprokets, in the hope that the issue is slipped timing due to stretched chain - if that is the case I will attempt to replace the chain and sprockets and see if it can be saved!

I do not have any specific tools other than your standard socket set, multispline bits etc - will I need bespoke MB tools to be able to do this, or will I be able to get by with a basic toolkit.

And finally, does anyone agree that it sounds like the cam timing has slipped - therefore causing all of the issues?

Thanks
Matthew

 

[markjay]

Welcome.

Google "M271 timing gear failure".

* And don't try starting the engine again *

(If you're lucky, the engine can still be rescued)

 

[markjay]

See also here:

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

Unfortunately we are seeing a common fault amongst the Mercedes-Benz W204 body C200 & C250 engines more often than we’d like to. Being Mercedes-Benz owners and fans ourselves, we hate seeing these beautiful cars having such a major issue. The problem mainly affects the later version of the M271...

candsservice.com.au

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

With this issue continuing to frustrate unsuspecting Mercedes C Class owners, we thought maybe we should go back to our initial write-up to continue helping those of you who may be suffering. This time we look closer at the M271.9 “Kompressor” 4 cylinder found in the W203 and early W204 bodied...

candsservice.com.au

And more specfically:

Fig 5. Here you can see the difference between an adjuster with worn teeth, and a new adjuster with hardened teeth.

 

[markjay]

I am planning to get the cam cover off, checkout the condition of the cams and the sprokets, in the hope that the issue is slipped timing due to stretched chain - if that is the case I will attempt to replace the chain and sprockets and see if it can be saved!

You will need new camshaft sprocket wheels, timing chain, tensioner and guides - if you caught it in time before the valves hit the piston crowns.

If there's already valve and/or piston damage, then I'm afraid that the engine is a write-off, as it will be beyond economic repair.

 

[matthewnorman]

Thank you everyone for the replies

I assume the right course of action now will be to take the cam cover off and start looking for timing marks to see how "out" of time the cams currently are.

Do I need specialist tools to change the chain and sprokets?

Thanks
Matthew

 

[markjay]

You'll need to establish first if there was valve-to-piston contact. Because if there are bent valves, then the engine is practically a write-off (keeping in mind that there will probably be damage to the piston crowns where they were hit by the valves, and potentially also damage to the conrods).

Unfortunately, you shouldn't really run a compression test on the engine, because turning the engine on the starter might cause the very damage you are trying to avoid/detect (if the valves are not yet bent)....

You might be able to use a borescope inserted via the spark plug holes. Perhaps someone else has an idea how to diagnose bent valves without turning the engine and without removing the cylinder head?

Trying to evaluate how many teeth the chain has jumped won't help much, because it will not be decisive enough in order to justify spending shy of a thousand quid in parts without confirming first that the valves are indeed not bent.

The good news, however, is that if the valves are not bent, and you find a way to confirm it, then the engine can be rescued by fitting new timing gear. That said, you didn't specify the age of the car, but you'll obviously need to take into account the value of the car - for example, a very early M271 car (e.g. 2003 W203 C180K) might not be worth fixing, unless the car is special to you in some way.

With regards special tools, I don't know the answer for fact, I did run a C180K with the M271 engine for 9 years but luckily had no issues with it. From memory, you'll need a special tool for the timing chain, but if you check online or on YouTube there should be plenty of info on how to replace the timing gear on the M271 (this engine was very popular on the W203 sold in the US, so there's plenty of info online).

 

[markjay]

See also:

M271 engine timing chain and camshaft sprockets | Engine

Hello all, Long story short, on my 140000km 2011 1.8 turbo C 180 I had an engine light that would disappear then come back and a fault code pointing at the intake camshaft sensor which I changed but no improvement. Tthen I heard a short diesel sound for one second every now and then and...

forums.mbclub.co.uk

The above relates to the M271 engine as fitted to W204 cars (2007-2015). But even if your car is a W203 (2000-2007), the principle is the same.