There's an on-going discussion on the X150 forum about the 5.0 supercharger torsion isolator. This is a spring-loaded disc that helps keep the supercharger spinning cleanly at low revs, by damping out the slight variation in tension on the belt when the car is idling. The problem is, the hardened spring, which is coiled around the input shaft, starts to wear grooves in the shaft. This leads to excessive play in the isolator, which then starts to 'chatter'; the sound is described as like marbles rattling around in the front of the engine. As the 5.0 cars begin to age, more owners are starting to report hearing this sound.

The problem is not unique to the XK, but applies to any other 5.0 supercharged model. It isn't even confined to Jaguar, as a number of other marques that use the same Eaton supercharger have experienced the same issue. However, a Jaguar Technical Bulletin JTB00349v2 has been issued about it. The fix involves fitting a "Supercharger Spring Isolator Kit".

The burning questions are: does this "kit" simply replace the isolator disc, is it the same design, and what is done about the existing wear to the shaft? One owner says the whole nose of the supercharger was replaced under warranty.

Can Jaguar tell us what is contained in the kit (part no. C2D38554 for Denso models and C2D38553 for Bosch models), and whether it is a permanent/long-term cure for the problem?

 

Might be an idea to copy this thread to: https://www.jaguarforums.com/forum/u...uar-crc-82019/ just a thought.. as I'm not too sure how often the Jaguar CS on here, scans through the threads..
Just a thought :-)

 

Ta - have done

 

Hi Ngarara

Thank you for your post.

I note your query and would advise that the kit detailed within the bulletin is designed to ensure a robust fix in relation to this concern. However, the Technical Service Bulletin is only a recommended level of repair.

As such, all of our retailers are able to inspect and assess concerns in each specific case and should any additional parts be found to be at fault, these will also be replaced to ensure the correct function of the vehicle moving forward.

Regards

Ryan

 

Thanks, Ryan.

We understand that each case needs to be examined individually; some owners have had the SC 'nose' replaced, others have received a new SC drive belt.

However, more information would significantly increase confidence in this fix. There is a concern that the problem will reoccur if the damaged parts are simply replaced with the same unit. Some detail on what is in the kit, and how this represents a "robust fix", would greatly reassure owners.

Can you tell us what has been changed on the isolator to avoid a reoccurrence of the problem?

 

Hi Ngarara

When a concern is identified, our Engineering and Technical Departments work directly with our parts manufacturers and suppliers to ensure that where necessary, any required modifications or updates to parts are completed to ensure a robust fix. This process has been completed as part of the Technical Bulletin.

Should you be experiencing a concern with your vehicle and require assistance, please visit your local Jaguar retailer who will be able to assist you.

Regards

Ryan

 

As I said above, I've raised this question on behalf of a number of 5.0 XKR owners in both the UK & US, all of whom would like some idea if this is a permanent fix or not. That particularly applies to those who no longer have warranty cover and are wondering whether to spend their own money to get the kit installed. Telling us all to go & pester our local dealer is not really a productive use of our time or your dealers' time, and is not really helpful - particularly if the dealers themselves don't know the answer, which they won't unless they've previously fitted the kit.

It's a simple question: what's in the kit? We're going to find out eventually - it would save all of us time & a level of concern if you could tell us now.

 

Hi Ngarara

Thank you for your post.

With reference to the technical bulletin in question, this has been produced to fully address this specific concern. While we can never fully guarantee that a concern will not recur in the future, any technical bulletin we release is done so to ensure a robust fix is implemented. We are confident that this will resolve any concerns that may be experienced of this nature moving forward.

For assistance with any vehicle concern, your vehicle must be assessed and diagnosed by a Jaguar retailer in the first instance. Your retailer will be able to confirm if a fault is present and advise on the required course of action. All of our retailers within the network are fully Jaguar trained and receive the latest bulletins to allow them to resolve vehicle concerns and also can raise any concerns with our Technical and Engineering Teams should they require further support.

The kit in question includes the relevant latest parts and please be advised that during the course of manufacture of any of our components we will continually modify and improve the design where necessary.

Regards

Ryan

 

Ok, Ryan, I'll stop flogging the dead horse - I appreciate there are strict limits on what you can say. The fact that you've confirmed that this is intended to address not just the immediate problem but also future reoccurrence (caveat noted) is of some reassurance. We'll just have to carry on with other avenues to get the detail.