I have a fine old knocking noise on my '98 XJ8 . The 'pipe in the ear' test gave me a black ear(!) and it seemed as thought the noise was coming from the front of the righthand bank.

It sounds just like the noise in the video 1999 Jaguar XJ8 VandenPlas Engine Noises posted by tempest.

Not quite the same engine, I know but the sound seemed familiar.
The consensus there seemed to be secondary timing chain tensioners, so I changed them today. The various posts here were very useful and it was quite an easy job once I had invested in the right tools. I changed both sides to the newer metal type.

Woe upon woe! Sadly the noise is still there. It started a few months ago when it was intermittent and fairly quiet. I thought it was a dry cam follower, especially as it seemed to go away after topping up the oil.
It's now developed into a very loud tapping, varying with engine speed. I can even hear it from inside the car.

I'm getting codes P1392 and P1397 which JTIS says are right and left VVT solenoid circuit related.

All suggestions gratefully received.

 

The ECM does NOT 'SEE' the VVT actuators electrically. You can do a continuity test to ensure that both the actuators and the wiring to the ECM are intact (DVOM).

You can also remove the actuators from the front cover and press the oil valve that the actuator pushes to listen to the engine (at idle) change 'state' as the intake cam advances (eg. idle RPM and/or 'smoothness') but that will trigger a different DTC.

Sounds like an electrical fault.

bob gauff

 

Thanks Bob. I'll try out your suggestions and let you know how it goes.

Do you think the fault could be causing the noise? I hope so. Fixing electrics sounds cheaper!

Thanks again
Graham

 

Got it! It was the 10A fuse 21 in the engine management fuse box. It must have blown when the MAFS plug was left loose and melted on the engine. All codes gone and noise much quieter. Also added a can of Winns to the oil just in case.