After inspection it is confirmed my tappets are worn. Service advisor is telling me that when tappets are replaced, valves need to be as well. There is no documentation they can find that says this is the case, just that it is what mechanics are taught in the training courses. As a result my warranty company is looking like they may not cover the valves/valve labor.

Anybody have any experience with this?

Thanks!

 

In modern engines such as the AJ133/AJ126, it's extremely rare to need to adjust the valve clearances unless the cylinder head has been disassembled and components in the valve train have been replaced.

It would be helpful to know the MY, number of kilometres/miles showing on the instrument cluster, and if any prior work had been performed on the cylinder head(s). Who performed the inspection to determine the valves and tappets need to be replaced?

 

2016 V6S unmodified, 39k miles, prior head work unknown. Brought it in because I was chasing a worsening ticking noise that did not go away at operating temp. Jaguar dealership mechanic suspected tappets, disassembled and confirmed tappets measured out of spec.

Do you happen to be a JLR mechanic?

 

I'd be interested in knowing in the opinion of the dealership Technician, how the tappets became worn. The only disassembly to check the valve clearances is to remove the cam cover(s) and rotate the engine in a clock direction to measure each valve's clearance.

I retired many years ago and now only work on my personal vehicles and those of friends.

 

Oh I see now you have a badge on your posts, thank you very much for the input. I guess quite a bit needed to be removed from the engine to access the valve covers because it has been costly. Fortunately I have warranty coverage for all of this.

I'll inquire as to an opinion on why the tappets became worn, especially at this mileage. I also plan to ask what shape the camshaft is in.

In the meantime, if you could weigh in on whether tappet replacement should/would/could necessitate new valves as well, that would be greatly greatly appreciated.

 

It would be very unusual to need to replace valves due to increased clearances (slight wear) of the camshaft to valve stem ‘buckets’ and shims.
it would have to sound like a bag of nails to have damaged the valve stem ends enough or the camshaft lobes are worn.
these engines don’t have hydraulic valve followers so the clearances are set for each with individual shims. Ticking during cold start is often a result of one or more gaps being too much ( I get it on mine) but lessens as the engine warms if and things expand closing the gaps.
if I were you, I’d get the clearances checked cold as one member recommended and see how much larger than specification they are. It may be just one or two. After recording that for all valves then removal of camshafts and then followers, measurement of existing shims will allow calculations of any needed replacement shims . Most importantly looking at the tips of the valve stems which the shims sit on, will confirm if any are damaged ( which I highly doubt unless the engine has been badly abused and oil not changed)
Good luck and keep us updated.

 

Having slightly out of spec valve clearances does not require replacement of the valves. Each valve has a tappet bucket that uses a shim to adjust the clearance between the bucket and the camshaft. If the clearance is out of specification, the shim for the tappet can replaced with a thinner or thicker shim to bring the clearance back into the specification range.

 

so let's say the max clearance is .25 +/-.02mm, or approx .009-.011 inches. how much knocking would you expect if one of my exhaust clearances is .014"? knocks pretty loud on cold start, seems to mostly dissipate after warming. thx!

 

actually it’s more like 9-10.5 thousandths so at 14 thousandths “ I’d expect a lot and it to sound very clattery. I think this happens a lot with these engines and why they tick do much on cold start and even when warm to a lesser degree in some instances (like mine). It’s a shame they didn’t use hydraulic adjusters. Cams have to come out to fix.. what a ball ache!

 

I had been hearing a loud engine tick and finally got it diagnosed and will be repaired under extended warranty next week, i have a 2017 R with 50500 miles on it.

Several of my tappets show signs of wear, see attached pics. I haven't really been given a good explanation of what could have caused this, but i have definite valve damage as well due to one of the values piercing the top of one of the tappets - this tappet moves freely and i assume is the most significant contributor to the tick i am hearing!!

 

I haven't been told that valves need to be replace aside from the one that has contacted the piston and pierced the tappet...