Recently installed new secondary tensioners, the updated short bolts and all new seals. Chains were fine and old 1st gen secondary tensioners were in OK shape. Did the job with the proper lockdown tools. Also installed a new interstate battery since the car had been sitting for a few months.

After this, noticed the car had a tapping noise which I though was the VVTs, but after using a stethoscope, the noise appeared to be coming from the fuel injectors (no codes or CEL). Ran a full tank of gas with Techron through the system and then went ahead and installed new NGK Iridium spark plugs (the old plugs weren't in the best shape), and then installed a new Jaguar oil filter and Mobile 1 5w30. The oil was definitely in need of a change, and unfortunately I'm not sure what weight of oil was used during the last change.

Well after cleaning the ignition coils, removing any leftover oil seepage from spark plug wells and new spark plugs -- the car flies! And more importantly, that tapping noise from the injector area is gone and the car purrs. I had almost forgotten how great these cars are to drive.

Now with the joy, comes some disappointment. After starting the car when it's cold or has been sitting a while, there is a definite clacking/tapping from the front engine area. This seems to go away after a few seconds (maybe 5) or if the engine is revved above 1500rpm. Didn't appear to have this type of noise before the oil was changed. Filled the Jaguar oil filter with oil before replacing it onto the car as well.

Any thoughts? I'm wondering if the car might need a good run to get some fresh oil into all of the seals after sitting so long. Or, if it's possible I got a bad oil filter from Jaguar and I should consider another oil change with possibly a different oil. I'm also considering replacing both the idler and tensioner pulleys as preventive maintenance since they're never been refreshed, just in case.

99 VDP with 60k miles.

Thanks for any advice

 

Sounds like VVT to me. It's a common problem. My XJ8 has done it for years. I suggest a search for tapping in this section, you will find lots of posts.

 

Obviously an oil pressure related issue.

Perhaps the old oil was thicker or had an additive or maybe the oil filter back flow valve is leaking. I installed a AP store filter and with it came a slow rise in oil pressure and ticking on start up. You can change the filter and loose much less than a quart.

A can of RESTORE, which is the common solution to worn VVT problems will tell you if that is the issue.

 

My 8 often starts quiet, but after a couple minutes at idle, it starts tapping. My theory is the oil pressure is higher when cold, then drops as the oil warms up.

Revving the engine stops it.

 

The first and second generation were a very sophisticated design, but plastic. Third generation, metal are not, but stronger. I read somewhere that third gens are noisier on cold start. If you look at them you can see why. Which is what i found on changing mine, had 3/8 and 5/8 inch cracks in the plastic ones, but noisy after upgrading. Couple minutes, quiets down. I changed oil weight and added expensive oil enhancers, still noisy on start up. After 18 months, learning to live with it. Cam timing working perfectly. Don't think it's VVT.

 

Thank you all. Will try to give it a good run-in for the next few hundred miles to see if perhaps an o-ring or seal might be stuck on the VVTs from sitting. Perhaps the thinner oil needs some time to clean off whatever sludge might be stuck.

Still want to do the primaries and the guides at some point, and now possibly the VVTs while the engine is open.