Timing chain tensioner (4.4i 2003 120k miles)

[RoShamBo]

Hi all,

Bit of history on this but a few weeks ago my 4.4 developed a loud rattle from the engine, out of the blue.
My mechanic came out and quickly diagnosed timing chain guide rails failed. Rang around a few specialists and they pretty much said the same thing based on the noise and not opening her up to see what the problem was.
I speak to an ex BMW mechanic today and he says that guide rail failure is actually quote un-common, and that more likely its the timing chain tensioner and to replace that. Seeing as its pretty inexpensive to do, makes sense to explore this before writing the car off ?

Wondered if anyone has any thoughts or past experiences on the above ?

Cheers

Ro.

[X5Sport]

Definitely get it done and no it isn't uncommon!  Loads of reports of guide failures on BMW V8 engines.  Dealers probably whack a new engine in as they aren't allowed to replace anything >:(

Failure results in seriously expensive engine repairs!  At least one member on here has been quoted over £5k to fix after a failure in that area.