Hi, I am using a W202, yes a W202 user not 124 user.

My question is simple, when do you change your timing chain ? I do not want to wait till the car breaks down to change it and I can't ask other W202 owner as most of their cars are below 80,000 miles.

My car is hitting 103,000 miles already, what would be the right time to change it ? Don't tell me MB claim that there is no need to change or something, I don't think that is safe especially on long journey we could end up sleeping on the road side.

thanx

 

Well, there are a couple schools of thought on when to replace a T-chain. I think MB recommends b/t 100-120K (on a W124), however, usuaully just the chain tensioner needs to be changed out at that mileage from what I've seen and heard from other techs and owners.

I was going to do mine at 137K in the 500E but it only needed the tensioner replaced. I would say with regular maint and oil changes you could go to 140-150K.

I'm not too familiar with your W202 motor but a few techs I know say they've never had to change a M119 motors chain...even in 200+ mileage cars, which is hard to believe, but I do.

Of course, if you hear a rattle upon start up for a few seconds, no matter what mileage; it is time to crack open the motor and inspect all that stuff. High torque motors can and do stretch the chain (s) (need to remove it to check anyway)....somehow, I don't think a W202 motor has the torque to do that though.

Bottom line...IMO if it makes no noises, then its OK.

 

When I bought mine on 120,000 miles I asked the stupid question of the dealer "has the timing belt been changed". Once he had stopped laughing he pointed out that it was a duplex chain not some cheap rubber belt.

So I asked when that should be changed and was told when it makes a noise.

At 145,000 miles the head gasket went. So while the head was off I asked the specialist to replace the chain. He rang me and asked why as there was nothing wrong with it and it was still well within limits for the tensioner etc.. He also went on to say that it should be good for 250,000 miles (mine is an early M104 3litre 24v 6cylinder)

Well now I'm at 165,000 miles and not a sound out of the chain.

At this rate the bloody head gasket will probably go again before the chain needs replacing.

 

A few months ago my 92 400E suddenly developed this loud banging noise in front of the engine. the engine will run fine but it sounded like a self firing M-50 machine gun. the only way I can get the noise to go away was when all spark plugs were removed (no compression). $1400 later found out that a camshaft adjuster went bad ($575 dealer item only). I asked my mechanic if, since we have the engine 1/3 opened up weather the timing chains should be replaced, he said NO, since at 145k miles its way too soon to go through that expenditure. He claims that he has seen chains with 300 K plus miles on them and that they were still "serviceable" when replaced at customer request. As a precaution, the hydraulic chain tensioner was replaced. Dual chains and easy on the torque should make those dual chains last a long time along with proper vehicle (lubrication)maintenance.