This is a long shot but just in case some one else has had this problem? My issue is with the 328 and the knocking noise that I get when driving over a small bump/pop hole etc.. even driving onto my drive way. It feels like I am carrying an item in the trunk and it kind of jumps a little? Also unless I am starting to here things it may make a little noise when I pull a way in 1st gear, a small clonk? like its taking up the slack? Today the car has just passed the UK Vehicle MOT with flying colours, all suspension parts are tight with no wear, The guy tested all items that could have movement! I am now thinking rear shock? Drive shaft? Any help would be appreciated..
I would check the allen head bolts holding the rear engine cover to the hinges... I have had them work loose, and make a pretty loud clunking noise....
Good advice, Tex. The 328 has regular hex bolts there...three per side. Just check their alignment and tighten up; I don't know about the inner (pivoting) parts of the hinges though. Open up the rear and look for other clunky things, too. Also make sure to latch both sides of the deck lid. Since you said it makes the noise when bumping on the road as well as when going into first, I can't think of anything driveline-based. It seems to be an inertia clunk. Years ago, I had an Isuzu Trooper that made a shock clunk that was mitigated when the shock was replaced...doubt it for the 328.
Rod it is a very good chance it is the shocks, I had the same problem the oil inside turns to glue. I had them rebuilt on the rears and the noise went away. If I remember yours is a later model, so it should be the yellow Bilsteins. Costs about £100 a corner to have them refurbed. PM me for more info. Regards Roy
I have the same issue but at the front, a knock which happens over small bumps. I am going to get all 4 Bilsteins rebuilt over the winter.
Nah, its not that , its the fibreglass duct piece rattling on the body (I think!). Its only secured by a single bolt on the end of a bracket ISTR. Might be I have a bush or a shock going bad back there but I don't think so.
I have the same problem. I put foam pipe insulation on the A/C hoses, thinking they were thumping. It echoes up high like shock bushing starting to go bad. Cannot find it anywhere. Cannot duplicate it on the ground. Only thing left is a bad shock. Like a front drive strut noise when they go bad internally.
I finally found it. It was the R side Decklid hinge just jiggling on bumps. Sounded just like a loose shock bolt.