The Gas Menagerie   JAGUAR & ROVER SERVICE

          Downtown Troy, NY             518-272-3087



Be aware that the early Jaguar V8 engines used plastic-bodied
   timing chain tensioners that are prone to premature failure.  When a

tensioner fails, its chain jams and breaks which disrupts the valve timing

relative to piston travel. Pistons and valves collide and the result is not pretty,

as illustrated in second photo. This engine is ruined.

Depending on the engine speed when this occurs, it may only bend valves

but this still requires removal of the cylinder heads to repair.

Aluminum-bodied tensioners were introduced late in 2001

and should be retrofitted to all earlier cars to avoid costly damage. 



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XJR engine with tensioners, chains and sprockets removed and cams locked

in preparation for installation of new updated tensioners

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Another problem with the early V8s involved the water pumps.
They had a tendency to lose their impeller vanes as indicated
by the arrows in the photo above. Needless to say, without
proper coolant circulation the engine overheats.
The car this pump was removed from showed just over
67,000 miles on the odometer. It suffered blown
head gaskets and both cylinder heads were warped from the heat.
It also dropped a valve seat as shown in the next photo.
The heads were straightened and reconditioned,
timing components were upgraded, and the car was returned to service.