Hi!


Hoping for some ideas from you all concerning a knocking noise on my 2015 V8S. It started becoming more and more obvious from about 5000 km on the odometer, now by 25000 it has gotten worse.


Most pronounced when cold, it becomes less when the car warms up. Closing the two open exhaust pipes quietens it down - nearly impossible to hear it then.


I have two sound files to listen to - the first one is a cold start, the second one is driving in an underground garage after a start (moderately warm).


Can someone tell me the best way to make the two .mp3 files available for to listen to?


Thanks DJS - I saw in some other post - link to a file on Google Drive. I'm doing this right now and will add a post with the links to the sound files

 

I think you need to have made 5 or 10 posts before you can attach files, so keep posting.

 

I learned how to do it


Here are the links to the sound files:


Number 1: Cold start


https://drive.google.com/file/d/10Di...ew?usp=sharing


Number 2: Medium warm start, slow driving in underground parking lot


https://drive.google.com/file/d/1eLr...ew?usp=sharing


Hope someone recognizes what is causing that knocking sound. Or do your V8's sound the same?

 

My 2015 sounds the same when cold, doesn't last long. In the old days we would have blamed it on hydraulic lifters. Not noticable when warm, or maybe I just don't hear it, couldn't really hear it on your recording of warm engine either.

 

i wouldn't say that these engines have NO character of that sound, but it does seem more pronounced.

 

It sounds very much like the "Torsion Isolator Coupler" issue. It generally will sound like a "box of rocks" near the front of the engine (if this is it) it is coming from the super-charger Torsion Isolator Coupler. Search the site for threads on it. I had mine done at ~62.5K KM. Cost was ~$2K parts & Labour.

 

https://www.jaguarforums.com/forum/a...rger-noise.pdf

 

 

Perfect excuse to buy a VAP system! Do it, you'll love it.

That said, I have the valvetronic system and my engine still sounds like the OP's at cold idle. Really does sound like lifters/rockers out of adjustment in the old V-8's.

 

Thanks for that statement, because that's really also my suspicion. The sound becomes less loud when I close off the two outer tailpipes, left and right, thereby only allowing the exhaust to pass through the muffler.


I actually also fixed both flaps in the open position as an experiment with two long pieces of wood - no way for them to rattle or flap against their stops. I checked that first.


I had reported this to the dealer and always got the reply: This is normal.


But it can't be normal, another V8 we had a look at did not exhibit this sound (but it only had 50km on the clock). Mine was fine before 5000km also.


A visiting Jaguar technical expert said it stems from the exhaust getting older (such BS!) and did not recommend replacing it, as the sound would allegedly come back after a few thousand klicks. In order to prove that the sound comes from the front, from the motor itself, I had the exhaust replaced anyway (I paid for the parts, the dealer paid for the work) - and lo and behold, there was no change in the knocking sound at all. QED - and I expected Jaguar to accept that something is awry. But they were steadfast in their assertion that this sound is normal for a Jaguar, even when I said I might sue.


At least the written history of this disorder is on file so that when the motor finally dies because of this, I can then start litigation. Until then, I try to ignore this noise, which is gradually getting worse - although I test drove a BMW M6 some days ago and that dealer sounded happy to take my F-Type off my hands, I am getting worn down by this.


It seems then, that anyone who buys a Jag V8 should know in advance that this is what a three year old 25.000km Jag V8S F-Type might sound like and this will be considered normal, as stated by Jaguar Germany - have fun all of you.


Does any one know how to get to the spark plugs so that I can run the motor in idle with one plug pulled, one by one, to localize which cylinder is the one going off its rocker? It seems to me they are difficult to get at.

 

i have a strange clicking noise did some one have the same ?
is somebody knowwhat is the problem ?

see my video

 

 

Originally, I thought that it might be oil starvation to a hydraulic lifter but from the sound bites it sounds more like a fan belt isn't quite aligned with the pulleys or tensioner.

 

I think Ichi means supercharger belt as there is no fan belt.

 

 

My V6S sounds exactly like this (the video in post #11). I have been told it's normal by the dealer on three separate occasions. You can only hear it when idling; it does seem to speed up when you rev the motor a little bit, but it doesn't take much to lose the sound completely in engine noise when you give it some gas.

 

Here's what my cold V6S sounds like:

 

The noise does bother me, but I'd say it has been present for over a year with no noticeable change in performance of the car, and no obvious worsening. I don't have any faith that my dealer can diagnose it, so I quit. Would love to hear if the new forum member from France figures it out.

 

in France i see two jaguar dealer , the first tell me it s normal , the second tell me yes there is a problem and they want change the compressor ( 4000 dollars )
when I went to pick up the vehicle after changing the compressor, which had a fault, unfortunately the noise is exactly the same. and for the moment nothing has changed the garage jaguar in France tells me that they are hydraulic presses but it is necessary to disassemble the entire engine

 

I don't believe any of the supercharged Jaguar engines in F type whether V6 or V8 have hydraulic valve lifters.

As has been mentioned one source of noise can be the supercharger coupler. There is a TSB (technical service bulletin) that describes how to examine the supercharger drive and determine if a new coupler nose is needed or whether the entire supercharger needs replacement.
If out of warranty then if the coupler only is needed it can be much cheaper in parts and probably a better fix to dismantle the coupler and just replace the defective isolator.

Another source of knocking noise has been high pressure fuel injection pumps, again there's a TSB that details this.

link to follow or search forum