I am beginning to make plans for the replacement of the upper timing chain tensioners on my '99 XJ8. I have made calls to several local shops, confining my search to those shops familiar with the engine with Jaguar-trained technicians. I eliminated one shop who claimed to do Jaguar repairs when the mechanic seemed to have no idea what I was talking about, and quoted me a labor price of $40.

My question is this: What is customary to pay for this repair? The quotes I have gotten are all over the place, from a low of about $900 to a high of $3,800 (the latter is a worst-case scenario, including replacing all tensioners and guides and all the timing chains and seals). My local dealer quoted me $1,200, which includes only upper tensioners and the installation of new cam cover gaskets. I was planning to do the gaskets myself, (a) as a cost-saving measure and (b) to check for the unlikely possibility that the previous owner may have already had metal tensioners installed.