I recognise that this might be a proverbial length of string question but I have heard a strange noise emanating from my 3.0i automatic and was wondering if it was normal or not. I don't normally have the car running in the garage with bonnet up but i did a few days ago when i was loading some music onto the hard drive. That's when I noticed it. Some facts first. The car has only done 20000 miles and has only recently (like 50 miles ago) been serviced by a BMW dealership (new oils etc). On picking up the bill, they didn't come to me with an ashen face saying "we have some bad news..." and remarked how nice the car was.
So, to the noise. It only happens at tick over (700rpm) and the noises I hear are valve gear rustle and injector ticking - normal. The noise that seems more "interesting" is one that comes from the bell housing area (foot of the bulkhead) not the engine block. It is a noise that sounds as though the engine is slightly out of balance - a bit like a spin dryer which has an unbalanced load in it. It's not overly loud (but it's still slightly noticeable with the bonnet shut) and it's not a crack, whirr, or rumble more a light thudding. While it might be caused by an imbalance, the noise itself has a regular rhythm to it (so thud thud thud).
It might have been there for ever! This engine/trans noise stops entirely when revved (or it could be being drowned out by the increased engine noise). The engine is relatively smooth feeling (eg the the vibration felt on the cylinder head) at 700rpm but not as smooth as I thought it would be. I thought it would be near still! Having said that my NSX (V6) is REALLY uneven at tickover but they are all like that.
Anybody who knows these cars well have any ideas please? Is this something normal?
So, to the noise. It only happens at tick over (700rpm) and the noises I hear are valve gear rustle and injector ticking - normal. The noise that seems more "interesting" is one that comes from the bell housing area (foot of the bulkhead) not the engine block. It is a noise that sounds as though the engine is slightly out of balance - a bit like a spin dryer which has an unbalanced load in it. It's not overly loud (but it's still slightly noticeable with the bonnet shut) and it's not a crack, whirr, or rumble more a light thudding. While it might be caused by an imbalance, the noise itself has a regular rhythm to it (so thud thud thud).
It might have been there for ever! This engine/trans noise stops entirely when revved (or it could be being drowned out by the increased engine noise). The engine is relatively smooth feeling (eg the the vibration felt on the cylinder head) at 700rpm but not as smooth as I thought it would be. I thought it would be near still! Having said that my NSX (V6) is REALLY uneven at tickover but they are all like that.
Anybody who knows these cars well have any ideas please? Is this something normal?