My '06 X350 failed its annual NCT ( Irish version of the MOT ) over the weekend because of a greater than acceptable difference in the front axle suspension between nearside and offside. The limit is 30% and mine came in a 44%. Car rides fine, a little firm and there are no warning lights/messages showing.

the damper in question would appear to be the offside front as it had a reading of 15mm as opposed to the other 3 reading between 24mm and 27mm. A new shock out of the box reads 20/25 mm .... Could it be possible that it is in a 'firm' mode and if so how do I change it....

as usual thank you for your input...

 

Not sure I understand you. Are you talking about the suspension heights ? These have nothing to do with dampers, but the air spring heights set by the Air Suspension Module using inputs from wheel height detectors.
Please clarify.

 

Sounds like a pair of front shocks could be required to solve your issue, just how many miles on them?

 

Hi Fraser...... this is how they explain it in their blurb The NCT tests a vehicle's suspension in two ways – a visual check for oil leaks and a mechanical test to identify any imbalance. The balance test identifies whether there is an imbalance between the vertical movement of wheels on either side of the vehicle.

 

Not too sure to be honest... I have put up about 8000 KM since I have had the car and their is 90K on the clock. Not sure if the previous owner replaced them as there are no invoices in the bundle that came with the motor...

New pair of shocks and the labour and tax to do the job would be about 1300 bucks over here ( 1000 euro )
If I need to then so be it but just trying to eliminate any other possibility.

 

Doing the job on the front shocks yourself is not a bad job, if the lower bolt breaks loose.

 

Do you have the same make of spring/damper unit on both sides ? At your sort of mileage, which is quite low for a 2006, I would not have expected there to have been any replacements needed. It would help if you can post up the actual test description as issued by NCT.

 

I think that the imbalance that you refer to is not an imbalance of height but of behaviour upon the vibration test.
This imbalance "reading" usually comes from the testing facility that is not equipped to test gas suspensions such as the X350's one.

In Belgium/Nederlands, its is wellknown and Jaguar has delivered a certificate that allows passing through a "failure".
I have encountered such a failure twice and the certificate was most useful to get a green light from the MOT.

Here is a copy of such certificate, unfortunately in Dutch.
Maybe you can get a similar certificate from the Jaguar dealership/importer in your country

 

Many thanks for your help but the NCT centers in Ireland are uniform throughout the country, all with the same equipment. They do tens of thousands Jags, Mercs and Audi's every year...all with some type of Air suspension and I have never heard of any 'certificate' to get a pass. My previous X350's have passed through the system with little problems over the years but this is the first time I have encountered this problem.
I have until the middle of January to sort out the issue and get a re-test on the suspension so I have a little more time to do some digging.

 

"the NCT centers in Ireland are uniform throughout the country"
I dont really believe that. Different country here, but sometimes you get an assessor plick "acting above their station".

And whilst I've never heard of or had this problem, I'd be inclined to present paydase letter. And the less Dutch they speak the better!

OR...does your suspension actually have an observable problem?

 

Google translation of paydase certificate.
"
Notification

We would like to draw attention to the fact that the car below was equipped with the optional "CATS system". However, this fully automatic, active suspension and electronishe damping only works when the engine is running and the car is not stationary. The system does not expect shocks at standstill and goes into standby mode. As a result, the car can never achieve geode scores on an EUSAMA test. Please take this into account please.
"

 

Cheers for that translation Chris..... very helpful.

In reply to your earlier post, there is no obvious problem that I can see with the car so perhaps it could be a calibration issue with the testing machinery, although they did test it in two separate testing lanes . Anyway, she is locked up from the cold and rain at the moment and I will get her looked at by my guy next week .

 

Just for additional info.
They have modern testing machines in Brussels.
I have had two X350's during a period of eight years up to now, both well maintained.
Only my current X350 had to have the front air springs/shocks replaced 2 years ago due to classic air leaking because of ageing, and had two Bilstein B4 units installed.
Apart from that, suspensions of the cars have worked flawlessly during all that period.

So, overall I had to pass 8 times the MOT equivalent test in Brussels.
I had to use that certificate on two occasions because of an off balance result at the vibrations test, including once with the new shocks.
Also, shortly before replacement of the new springs/shocks, so with already worn springs, the MOT was passed successfully.
So, failing to pass the vibration testing does not depend on the soundness of the air schocks, but on the specifics of the Jaguar suspensions set-up, and that certificate may be really very useful!

 

That's exactly what I was thinking, Paydase.
This is my third X350 and previous to this they have all got through the test. Thank you for attaching that certificate, I have already e.mailed the main Jag dealer ,here in Dublin, to try and get a similar version for the Irish market.
Again , many thanks for your help and I will report back on the outcome..

 

Just a quick update. I let my indy guys take a look at her last week and they re-calibrated all four corners and made sure my tire pressure was correct.
Bottom line is it sailed through the inspection with zero advisories etc... very please.
I had that certificate from Jaguar Benelux printed with the English translation in my glove compartment but I didn't need to produce it.
Thanks for all the input guys.

This is her....