My 2001 Disco II has done 200,000 km. Service Manual says to replace the timing chain. Is this necessary? Advisable? Imperative? Optional?

 

are you sure it doesn't say replace at 200k miles? That's the mileage I personally think is a good time to change the timing chain.

 

I have read about people driving 230,000-250,000 miles without replacing the timing chain. I don't know if that is a smart thing to do but they have done it and have not had any problems.

 

If my math is correct 200k = 125k miles it is not "Imperative", but the next time you into the motor to replace the water pump or camshaft sensor you should consider it while your there. I do not "think" like a lot of engines today that the valve to piston clearance is so close that a piston will strike a valve if it does break. I am sure someone will correct me on the last point if I am wrong.

 

I just got into this conversation with someone on another board. From what I'm hearing, you are correct (about the 4l and 4.6l at least). I didn't think it was with this old push rod motor, and it doesn't appear to be that way based on the service/rebuild manuals, but people who ought to know are saying it is.

As I tear my spare motor down I'll be measuring and see just how bad of an interference fit it actually is (out of my own curiosity).

 

Around 180,000 miles and up and also replace the oil pump and water pump at the same time.
The other option is to replace the cam and lifters at that mileage cause they will be worn out.

 

Where did you get this info?
The dealer?
Your mechanic?
The owners manual?