Last night I took the XF back to the exhaust place that recently fitted my extractors and 2-1/4 inch system, because it has started making a loud, metallic, tinny, rattly, vibrating sort of noise at around 1000rpm when the auto is in "drive" and I'm accelerating gently. If I hold the brakes on and push the accelerator just a bit I can keep the noise going for a while and it definitely sounds to me like the exhaust is rattling itself to pieces, like a flange connection is loose or a heat shield is hitting against it or something.
The guy said it was noisy lifters, can you believe it? The engine was rebuilt in about Feb 99, so I reckon he's trying to do me over. Does anyone out there think that noisy lifters could sound like an exhaust rattle? If it *is* lifters, then I guess I'm up for big bucks to fix it.
It's probably worth doing the cam at the same time.
I'm going to get a second opinion on the weekend.