As we know, the N47 engine has a reputation for timing chain failures related to the design of the crankshaft sprocket. However, having just searched through Autotrader there are lots of examples of high mileage cars (1, 3 & 5 series) which have in excess of 100,000 miles and right up to 170,000.
Although some of these cars may have had rectification of the timing chain related issues, I'm sure there must be a lot of them that have managed to get to high mileage without any attention.
This raises the question as to whether there are any external factors which contribute to the premature failure of the chains, i.e. town driving, or whether motorway miles extend their life? Could there be other factors such as more frequent oil/filter changes or driving style? Are failures more common on manuals than automatics?
Although the main cause of these failures is undoubtedly down to the design of the engine, I'm curious to know what your opinions are on this subject and perhaps members could tell us here how many miles they have on their N47 engine, the type of driving they do and the frequency of oil changes and whether they have any timing chain noise from their engine.
My manual 520d has just reached 80,000 miles, has only had CBS scheduled oil changes and sounds fairly quiet at present (hopefully to remain that way) I believe most of the miles covered were via motorway before I purchased it.
If we collect this information we may be able to spot any common influencing factors, so post up your info,
Although some of these cars may have had rectification of the timing chain related issues, I'm sure there must be a lot of them that have managed to get to high mileage without any attention.
This raises the question as to whether there are any external factors which contribute to the premature failure of the chains, i.e. town driving, or whether motorway miles extend their life? Could there be other factors such as more frequent oil/filter changes or driving style? Are failures more common on manuals than automatics?
Although the main cause of these failures is undoubtedly down to the design of the engine, I'm curious to know what your opinions are on this subject and perhaps members could tell us here how many miles they have on their N47 engine, the type of driving they do and the frequency of oil changes and whether they have any timing chain noise from their engine.
My manual 520d has just reached 80,000 miles, has only had CBS scheduled oil changes and sounds fairly quiet at present (hopefully to remain that way) I believe most of the miles covered were via motorway before I purchased it.
If we collect this information we may be able to spot any common influencing factors, so post up your info,
. In the end I was driving around with the vent off constantly, listening for that slight chain rattle 24/7. 
