X5 Noisy Diesel

[sja]

My X5 53 plater 3.0d 85,000 is now staring to sound like a rattly old taxi at low revs and low speed. Cruusing its fine, no drop in performance and once the turbo kicks in stil sounds fine. Its just when staring up and pettering about. I posted on x5Drivers.co.uk and asked if an oil change would help. I was then notified I had probably missed an oil change due to inefective service lights as I have been prompted for Inspectiion / olil service in 20,000 miles. But thats another issue.

So I'll be having the oil changed today, but if that doesnt quieten down can anyhtjhing else be done?
And whats he donside to having the same oil in for 20,000 / 18 months?

Thanks in advance..