This is a prime example of what you do not want to see happen to your Jaguar. On the early XK8 and XJ8 Jaguar vehicles equipped with the 4.0 liter motor, there is a known flaw in the upper timing chain tensioner. What happens is that the chain tensioner fails, causing the chain to slip or completely break like you see here, causing damage to the valves. This has been a known problem for many years that Jaguar fixed when they went to the 4.2 liter motor.

Broken Jaguar Chain
Broken chain as a result of tensioner failure.

Until recently, upgrading the timing chain and tension to the newer style was a major undertaking because the whole front of the motor had to be disassembled. In the last few years, an upper timing chain/tensioner upgrade kit has been made available. This is a great kit which cuts the time of the job in half, saving you lots of money on labor.

Jaguar 4.0 Liter Timing Chain Upgrade Kit
Jaguar 4.0 Liter Timing Chain Upgrade Kit

Doing this update is no easy task and should be done by a qualified Jaguar repair facility only. Most shops will attempt to do this update but will run into problems when they realize that special equipment is needed to for the job. We have cars towed in from other shops doing this repair all the time because they get in over their heads. If you own a 4.0 liter Jaguar and do not know if this update has been performed on your car, it’s definitely in your best interests to have it checked out immediately. If you have any questions about this update, please do not hesitate to shoot us an email or give us a call.