Since my friend has a 2006 c230 sedan, I have been reading w203 forum in the last few days. Apparently, w203 has timing chains issues because the chain only has one row.

I read that most other timing chains are double-rowed. How about w209? More specifically, how about a 2004 CLK320?

I always thought that timing belt should he changed every 100k km but not timing chain.

 

The concern with the single-row timing chain is on the I4 engines (M111 and M271). All the V6 and V8 engines (M112, M272, M113, M273) have dual-row chains. Timing chains should be good for at least 250K miles, but there have been some cases of M11/M271 chains breaking before that. It doesn't seem to be common, but if you have one of the engines (which your friend does not - the MY2006 C230 has a 2.5l M272 V6), then you could replace it. It's not terribly difficult. In fact, it's probably easier than replacing a timing belt on the typical FWD car. You remove the valve cover and splice the new chain onto the old one, then manually rotate the crank to draw it in. Of course it's not quite "that" simple, but that's the basic procedure.

 

+1^. The M271 problem is preceded by a clear chain rattle at start up after standing overnight until the oil pressure comes up.

Duplex chains don't give any problems on the bigger engines other than the early M272/273 balance shaft sprocket issue.

 

So, this chain rattle is normal at start-up? Can this rattle be felt inside the car compartment?

You just reminded me of the balance shaft issue. 2006 M272 would fit the range, right?

 

The chain rattle is not normal at start up. It is a sign the chain has stretched. You need to listen at the front of the car or with the door open to hear it. It can also be confused with cam adjuster rattle to the non initiated. (due to burring on the I4 engines.)

2006 M272 would fit the range for balance shaft sprocket trouble.

You have a M112 engine so no worries there. I have never known a M112 engine have duplex cam chain trouble even at extreme mileage.

 

I have a 500 with the m113 engine, I get a ticking noise at a cold start, could it be an issue with the timing chain? its been happening more frequently as the car ages. Can the chain be adjusted or does it need to be replaced? if thats even the issue

 

Unless you have over 300K miles on that M113 engine, I would not think you'd be having timing chain issues. It's more likely just slightly clogged oil passages causing a little vale tap until things warm up. That's perfectly normal.

 

It's likely a hydraulic lifter taking a little while to pump up to zero lash. If it did it all the time it would likely be the purge valve getting noisy which is common.