Non VW - V12 Jaguar - Valvetrain Help.

Hey I was just working on dads V12 Jaguar, there seems to be a ticking noise (Sticky valve or similar noise) coming from number 12 cylinder overhead valves and or cam.
My question is has anyone come across this problem or do you have any diagrams/pictures of the cam/valvesprings etc themselves as I'm not sure whether or not they use rockers being an OHC engine.
Unfortunately removing the valvecover requires the removal of the intake manifolds, water jacket/manifolds, primary fuel system etc etc etc... so hopefully it's something someone else has come across before.

Thanks in advance.
-Staggers.

The problem is its a Jag.😁

Hehe no no, the problem is it's not mine! Yet...
But if it helps anyone, the car is a Series 2 XJ12L.
-Staggers.

V12 jag, overhead cams have a notorious reputation when it comes to valve adjustment. A real bugger to get right. And very fiddly to work on as well. Doing them right is a real work of art, you need to find yourself an artist.

Matt.

Being a 3rd year diesel apprentice, I need to learn!
Mind you after a quick service it's cleared up a fair bit.
-Staggers.

A dud hydraulic lifter will produce this sound. Are yours solid or hydraulic?

No lifters, found out the setup today.
They run followers sraight onto the cam from the valve.
Seems to be okay for now.
-Staggers.

From memory I think they are adjusted by adding & removing shims and you have to pull it all apart, reassemble and recheck each time, which is why you really need to have a "feel" for it, after all, there are 24 of them to do.

Dont take my word for it though, I've been out of the trade a long time and jaguar may have changed the way they adjust.

Matt.

The OHC jags run the cam straight onto the valve and is similar to a VW set up

the spring has a upside down cup and uses shims to adjust the clearance

It may be a broken spring you could do a compression test on and see if theres any difference in # 12 to the others

I rebuild a V12 engine bout 20 yearsago... and the cam timing is not vey clear as the timing marks are on the reverse side of the drive gears

Thanks people, it seems to have cleared up with a few oil changes.
If there's any problems down the track I'll keep ya posted!
Oh here's the Jag V12 in her shiny glory...





-Staggers.

Okay just tested her out...
Spins out to 100kph on the spot in no time.
🙂 Happy enough with the performance for now.
-Staggers.