valve /cam replacement

[blaineuk]

been to look at a 4.0 chimera today every thing ok except for what sounded like a exhaust manifold blow but i suspect it to be a burnt out valve. any idea on cost of doing just valve or while it is stripped replacing the cams if they turn out to be worn.

cheers
blaine

[pupp]

Assuming the car is not running aftermarket 'solid' lifters set up with too tight /no clearances, it is unlikely to be a valve. Standard set up is hydraulic ... manifold gasket is favourite candidate.

At 40k + miles perceived wisdom seems to be that cam wear is likely (although it is often said the 400 is less prone to this) although it would have to be pretty well donald-ducked to be making a racket and I doubt you would confuse that with manifold chuffing (albeit that can sound 'mechanical')