2001 XJ8 VdP.
I knew this car didn’t have upgraded tensioners when I bought it last year. I had the parts and gaskets to do the job and I’d been planning to do it this month during some vacation days I have. I wasn’t too worried since the car only has ~54000 miles on it. The new tensioners we’re going to be preventative maintenance. I’m glad I did it though because both tensioners had cracks starting along their axis.
The new ones are in now and I can rest easier.
The photo shows the cracks starting. These went into the trash bin.

 

Each and every startup is like Clint Eastwood asking "do you feel lucky.....punk"....the closest thing to Russian Roulette in automotive manufacturing!

I can imagine the meeting between the Sachs exc's and the bean counters at JLR (Ford)

Jaguar "But they're plastic?"
Sachs "But they're a 10th of the cost"
Jaguar "Oh, that lowers engine cost dramatically"

A couple of years later.....lots of broken engines.

 

aguar "But they're plastic?"
Sachs "But they're a 10th of the cost"
Jaguar "Oh, How long will they last?
Sachs: 50k miles at least.
Jaguar: ahhh outside the warranty, huh?
Sachs: Yeah and nobody will figure it out till it's too late.

A couple of years later.....lots of broken engines.

 

some made it well into the 200s with these. i just pulled one out of a 160k engine

 

Yep, there are still some Studebakers on the road too.

 

I had a customer with a 2001 S-Type 4.0 AJ28 engine with original chains,tensioners,guides and blades at 254,000 miles.
She had the car since NEW.
Her gearbox (5R55N) finally failed so she scrapped the car. This was about 10 years ago and I was amazed.

I advised her to replace the timing components but she 'never got around to it'.(moot point when the gearbox went out)

 

Absolutely. Without a doubt, they CAN last a while, however it is also without a doubt,
they fail more than they last. Shame about the gearbox.

 

It sounds like she never shut the engine off so I can understand why it lasted so long. They more so fail at first startup.

 

I also had AJ26, AJ27 and AJ28 engine timing components fail in new car warranty when I worked at the dealer. (less than 4 years, 50,000 miles)

The most spectacular was an X200 (2000-2002 S-Type) 4.0 AJ28 that broke the secondary chain that 'wadded-up' on the intake sprocket and pushed out a large part of the cylinder head.

Jaguar replaced the engine with a reman unit so the customer was 'made-whole'.

We were well aware of the plastic tensioners.

 

Now THAT is funny!

 

Real world confirmation that these cars are meant to be driven?

 

Yes, they are meant to be driven. But they’re also meant to be maintained!

 

Automobile engineering has definitely evolved over the years. The initial engineering
of safeguards and warnings on our X308s were obviously designed to augment our
driving experience even as father time causes degradation and sometimes painful
diagnostics in order to chase down that errant warning light. Overall though we should
be very happy with the thoughtfulness and consideration the engineers provided for
the sophisticated and beautiful X308. To me, there are very few cars that even approach
the styling grace and rich environment provided by these cars. The Duchess is a daily
driver that always feels good and provides that "spark" of proud ownership.