A couple of times over the past few weeks, when we start the engine, there has been a noise that sounds like it is coming from an item which is belt driven, however, it disappears very quickly. Today when we were coming out of a multi storey car park, it started again and as the lights were on, I noticed that the head lights dimmed as the noise started, again it stopped very quickly. Can anyone suggest what it could be?

It is a 2010 FL2 TD4, 70000 miles with full LR service history.

Cheers
Paul

I would suspect a dry alternator bearing ?

If the noise is like a squeal, it's possible that the generator load is too great for the accessories belt and/or its tension and the belt slides/skids over the generator pulley.
Check the accessories belt tensioner and eventually change the accessories belt if it wasn't changed up until now.

Largered wrote:

I would suspect a dry alternator bearing ?

alex_pescaru wrote:

If the noise is like a squeal, it's possible that the generator load is too great for the accessories belt and/or its tension and the belt slides/skids over the generator pulley.
Check the accessories belt tensioner and eventually change the accessories belt if it wasn't changed up until now.