I’ve just had my car serviced (27,000 miles over 5 years) and I got an advisory that the front upper wishbone rubbers are perished and will need replacing soon (they also included a video showing the perished rubbers).

 

My last car had covered 12,000 miles over about 15 months when I bought it, then I covered another 40,500 miles over the 7 years I owned it and this problem never occurred.

 

This leads me to think that maybe something isn’t quite right and there maybe an underlying issue that I should get resolved whilst the car is under warranty.

 

This also raises the following questions in my head;

 

1. Is there a possibility of an underlying issue that has led to this early deterioration?

 

2. Would this be covered under my 2 year Jaguar warranty?

 

3. Would buying OEM parts invalidate my warranty?

 

The research I've done so far indicates that these “rubbers” are not individually replaceable, but are part of the upper wishbone assembly, which comes with a substantial price tag, plus the labour cost to replace it.

 

The part numbers I’ve found online are:

 

C2P25603 – Genuine Jaguar Right Front Upper Wishbone (£390-£430)

C2P25604 – Genuine Jaguar Left Front Upper Wishbone (£390-£440)

C2P16948 – OEM Jaguar Right Front Upper Wishbone (£125-£142)

C2P16949 – OEM Jaguar Left Front Upper Wishbone (£125-£142)

 

As my car is under a 2-year Jaguar warranty, I feel I should use genuine Jaguar parts and the suppliers I have found so far are SNG Barratt, Moss Europe and Brit-Car.

 

British Parts and Berkshire Jag Components only seem to stock the OEM parts, which are about 1/3 of the price.

 

I’ve consulted my workshop manual and there seems to be considerable labour involved, namely the removal of the Shock Absorbers, plus the ECM on the left-hand side and the coolant expansion tank on the right-hand side.

 

Opinions /advice please?

Are you talking about the boot over the ball joint or the bushings themselves?  The Ball joint is integral to the unit so the control arm needs to be replaced in it's entirety if it's bad.  If the rubber itself is the only issue, you can by replacement rubbers.  

The symptom of a bad upper control arm is a thumping or clunking over bumps.  To test them you need a pry bar and there are a myriad of views on how to do that.  You should see less than 1/8" of movement up and down using a pry bar.  Now you want to be careful not to tear into the rubber boot but if it's already set...

 I'm in the US but here is a UK supplier:

https://www.balljointboots.co.uk/index.html

You only need calipers to get you fit right and that's fairly easy.

If you need to replace the bar, Note, when Ford took ownership of Jaguar, they used the same control arms as on their Lincoln's, Thunderbirds, S-Type, X350's and XK.  They are easily replaced and can be found for less. 

Here's an example:

FRONT
MotorCraft MCSOE38 = Jaguar  6W4Z3084AA
MotorCraft MCSOE39 = Jaguar 6W4Z3085AA

Here's a link on eBay.  These will fit your car

https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=6W4Z3084AA&_sacat=0

To address the warranty question, OEM is original manufacturer so no using that can't void your warranty.  Sorry, I'm not a warranty guy bu would suspect that some warranty's would attempt to require OEM, but I doubt it.  You should certainly pursue it.  They may call it normal wear and tear and not cover but worth the effort imo.