651 Timing chain tensioner replacement

[john campbell]

Just a quick one ................
I own a e250 and I'm thinking about replacing the chain tensioner but unsure if this can be done without the engine locking tools. Is it as simple as taking the old one out and putting the new one in ? I don't have any noise at start ups but once warm I seem to get a rattle noise from the turbo or back end of the engine that sounds like a heat shield rattle but everything has been checked and ok so I'm at a loss. I'm now thinking is it the chain tensioner causing this because I can't find anything else and everything else that I have been reading about the chains all say that the rattle is at startups but mine is not. Sometimes it's not that loud and other days it is and it's been like this since I bought the car 4yrs ago at 47k miles. The car now has 71k on it and the oil has been changed every 6k. I'm not really worried about it but I would like to get to the bottom of it and fix it before anything might happen because it's my daily car and I need it for work.

Many thanks

 

[gianton]

Engine locking tools not needed, it’s time consuming though. My indie did it in about three hours. I had mine changed at 175k miles.

 

[john campbell]

Thanks for the reply......... I just want to rule out a chain problem before it becomes a problem.

 

[Misterdog]

I've considered changing mine, it is external and only held on by 2 bolts. Apparently the tensioner can get a bit lazy and is one of the few components you can actually get to on my W169 A Class.

I believe the timing chain maintenance interval is - 'the lifetime of the vehicle' meaning that if/when it goes you need to buy a new car....

 

[Suhail Khan]

hi
I've done my tensioner on my e250 cdi at 157k miles - 20months ago with the help of a very strong pair of hands
engine is quieter on a cold start.no issues after 20k miles

steps are to remove airbox and a steel place that keeps hold of some pipes
put the engine at TDC using timing marks
then its quite limited for space to get to the tensioner so the tricky bit is to fit a socket in the gap
unbolt the tensioner and remove
PRIME the new tensioner by pressing it in and how while on its head in fresh new oil ( so the head of the bolt submerged to oil so it can suck oil in)
then screw in the new tensioner ( is VERY tricky-this took the longest because the tensioner is quite hard after priming it)
tighten to 85-90nm if i remember correct
then build it back up =)
total time was 90mins in total

 

[Manc Rick]

Wow, 90 mins seems very quick, considering it’s right at the back of the engine (afaik). Suppose it helps if there are two people though. Bravo