Not on my car... I've done 4 or 5 other Jags as well as mine. Even one with the LATEST style tensioners... They were original parts and badly worn. Not cracked but worn. One had the New secondaries fitted and old chain guides. They were basically just a thin later of metal...

Every material loss results in a lower tensiondurability. A steel cable with 10 strands can hold say 1 tonne. But when 9 have snapped, it is f**ked.

My chains (secondaries) were badly worn. I measured something like 3/10th of a mm thinner/worn than the outside...

And why replace the whole lot? Because the plastic guides will just fall apart. How can they be less fatal? Instead of just one cam being damaged, all the cams on one side (therefore all the valves) will be knackered.

Saving money, okay. But not when it come to important parts IN the engine.

You can get full kits for less than €200 with the same 'quality' Jaguar offers... Why then just sabe a couple of quid/dollars/euros/yen/stones/bitte caps on just bodging two tensioners? Most Jobs I repaired were bodge jobs. Timing wasn't even with in spec afterwards... When I finished the timing was 100% and everything was like new...