300SE Timing Chain guides

[rogueinla]

Recently bought an 89 300SE, with a slight noise from the front of the motor, took off the distributor and the timing chain cover, and the chain guide on the drivers side is missing. Well, not 'missing', I can see it down in the block, but when I looked at one in the local boneyard it is definitely longer than what I've got. How much trouble am I looking at to replace this? Looks to me like the front cover has to come off? Is this as big a PITA as I think it's going to be? Or should I just get a bottle of tequila and mourn my "good deal". The chain guide pieces I can see look to be pretty brittle, the car has 140K on it, I'm assuming the chain guides should last longer than that. Thanks in advance.

[Mercedes Guy]

On your model of MB it's very important to replace the timing chain and guides every 10 years or 100,000 miles. The chain guides begin to get very brittle and if they shatter they will do major damage to the valves. The chain will likely jump time and bend the valves, requiring a major top end rebuild.

If the chain and guides have never been replaced your vehicle is well overdue. Certainly do not start the vehicle until you have done this service, because if the guide broke without causing any other damage you are unbelievably lucky. It's not extremely difficult to replace the chain and guides, it just requires some time and know-how. Good luck.

[wbain5280]

It's not a major PITA, but a lot of equipment has to come off the front of the engine. Chain stretch is not a major problem on the M103 but they do need the guides.

[rogueinla]

Thanks, I'm surprised tho, I've never really dealt with Mercedes before, thought they were good for at least a couple of hundred thousand miles before things broke. Anything I need to know in the way of special tricks or tools to take off the front end?