I purchased a 2016 S last month, as part of the purchase I had the dealer replace the upper and lower coolant pipes, the thermostat and housing and the rear heater pipes, the SC belt and the plugs. While in there I asked them to check the water pump and the Super Charger coupler as everything was out anyways, they told me all was good.
I have the car back now and while I can't hear anything from inside the car I happened to have it running while out of the car and could hear some knocking. Pulled the engine cover and the knocking is pretty loud. Searched the forum and I have had some people say a similar sound is normal and others say it is the coupler. So here is a video of mine, please let me know your thoughts and if it is the coupler how serious is it, the reason I ask is I intend to have the main drive belt replaced over the winter so wondering if waiting is fine. Cheers and thanks in advance.

 

Best way to tell if this is the coupler, remove the SC belt and see how much play you have in the SC pulley if you rock it back and forth, should feel connected and smooth, not making any sort of rattle or clacking sound. From the video, I personally cannot tell. Sounds like the HPFP to me, but videos are deceiving. Also, there is no way the dealer would have taken the snout apart to know the condition of the coupler, without a huge cost. It is not a simple thing to do. Required disassembly and reassembly, need to re-seal the snout. It is a pain in the ***. So my guess is they may have visually inspected the outside, but not the actual coupler.

 

Good advice above!
Another trick?

Usually this noise is very noticeable on engine shut down. With the car running open the drivers door. Now shut off the radio. Now shut off the engine and listen. There is a rather loud clunk as the engine shuts down. This is the easiest way I have found to determine this.

Now it's not something that's critical and my car has been doing this for at least 20K miles. If left too long then the spring on the coupler can and will eat into the snout shaft. Then you need to replace the entire snout and not just the coupler but be aware there are bearings in the snout so it's not a bad idea to replace the entire assembly anyway. But it is more money for sure!

Note this is NOT an absolute requirement and many have simply installed the new coupler on the worn snout shaft. Your car-your choice!

Here is a picture I stole from Reaxions in one of his VERY useful threads!




Note the reddish color is from rust and there can be quite a lot of it depending on the car.

See attached service bulletin discussing this problem.
Note I have NOT discussed the solid coupler or spring coupler variations as that is another whole chapter of SC repair!
I favor and recommend the Eaton factory solid coupler above all others.

Did you use the Aluminum pipes?
.
.
.

 

Thanks Skizot, I am assuming they checked for play, but you never know. They did have the SC fully out. So the fuel pump can make a sound like that, never would have guessed that. Guess I will need to see how to loosen the belt. Thanks !

 

Thanks, no knock on shutdown, its why I tried to record it at the end of the video. I really can't recall how my previous car sounded hence the question, its been four years. Sounds like I can wait until winter when I have the other work done!

 

from what I can tell your sound sounds different than mine (https://www.jaguarforums.com/forum/f...g-idle-282981/) can you confirm? just want to see if we're tackling the same problem or not

 

​​​​​​Sounds similar but yours has some moments when it seems worse than mine. Mine is pretty rhythmic and steady. Someone suggested mine maybe the Fuel pump. I will try taking the belt off and see if there is play. meanwhile I am looking into the HPFP.

 

Let’s clarify a couple of things: there are two engine-mounted high pressure fuel pumps. They are, by nature, noisy, therefore and contribute to the general “clicky” engine noise common to direct fuel injected engines. This noise does not indicate malfunction, but an excessively noisy pump might suggest replacement. An educated ear is needed to differentiate between normal pump clicking and a pump needing replacement

Next, if the SC coupler does not knock/clunk excessively when the engine is shut down, then it is not likely to need replacement. My 55,000 km V6S had a single knock/clunk on shut down, and always had this noise. But when the coupler was removed (as I was having aluminium pipes installed in place of the original plastic pipes), it was found that neither the coupler nor the shaft itself showed ANY signs of wear. The shaft was in perfect condition and rotated freely. The sort of damage in the photo shown in an earlier posting is probably not common for a car in normal use.

 

That is great information, thank you. Maybe not something I need to worry about which is always nice. For sure i am taking away it isn't urgent and can wait until the next time i am having other work done. Cheers and thanks again.

 

Further to my posting #8 above, here are photos of the original coupler from my 55,000 km V6S. You can see the condition of the coupler shaft.

 

Still looks like new, appreciate the responses, really nothing serious to worry about at this point!