My 406 has recently developed a rattle on acceleration.
It's not audible if the revs are being held constant, but it's really clear when the revs go up. If I pump the gas a few times, it's most apparent. It sounds rather like it's coming from just behind the driver's side firewall.
I've had a brief look inside the engine bay and everything looks (on a cursory inspection) normal. A quick check on t'internet suggest that I'd be best focusing my investigation on the exhaust manifold.
Gut instinct suggests that it is an exhaust issue as it feels just a tad sluggish. The exhaust (Everything after the cat) has recently been replaced; could the cat have blown?
Should I be worried? Is this going to cost me an arm and a leg?
John