Just wondering for timing belt ot chain?

How often it shoyld be changed? every 100,000km?
or first 100,000km, after that, 50,000~70,000 km?

Thank you.

3.5 litre is the M272 engine

http://en.wikipedia.org/wiki/Mercedes-Benz_M272_engine

Double row chain drives intake cam shafts, exhaust cams driven from gear off of intake cam.

I've never heard of it as a "maintenance" item.

https://mbworld.org/forums/e-class-w...placement.html

saw this thread...so anywhere between 150-250k miles, maybe more...I think the rest of the car will have to be replaced before that chain.

I know old Nissan Maximas had chain and it had to be replaced at 120-140k miles.

Our engine is chain driven and it almost never needs to be replaced, unlike belt.