N42 rattle

Post Fri Mar 11, 2011 9:42 pm

I got this problem with a 318ci. On idle you can hear rattling noise in the inlet manifold area. Does anyone know what this might be?

Post Fri Mar 11, 2011 10:52 pm

the all to familiar death rattle.

give it a rev and listen to the rev decent chain Buzz!

take the rocker cover off and see if the upper sprockets have wear and if you can move/lift the chain.

Post Fri Mar 11, 2011 11:11 pm

timing chain tensioners are rubbish and allows chain to jump but you can be lucky with only guides damaged, new tensioners are modified and slightly longer

Post Fri Mar 11, 2011 11:41 pm

Its fine when you rev it, only seems to be at idle. Its more like a ticking noise, kind of like a diesel.

Post Sat Mar 12, 2011 12:05 am

get a scope on it and rev it and listen to it on the run down to rule out the chain ect as its standard fair on these engines if not injectors would be my next place to check.

Post Sat Mar 12, 2011 1:16 am

toadster987 wrote:timing chain tensioners are rubbish and allows chain to jump but you can be lucky with only guides damaged, new tensioners are modified and slightly longer

This happened to my girlfriends '03 318ti at 23k.

Post Sat Mar 12, 2011 7:27 pm

It will be the exhaust vanos unit, last one I did had broken the end of the camshaft were it drives the vac pump which I think was probably caused by the problem with the vanos been ignored for so long. Usually replace the tensioner at the same time as the vanos unit.