Jaguar XJR (X308) 4.0 V8 Supercharged · 1998 · 4.0-litre supercharged V8 (AJ26)
Jaguar XJR timing chain replacement
Completed October 2026 · Southern VSR Ltd, West Harting
This 1998 Jaguar XJR came into our West Harting workshop with the classic early warning signs of timing chain trouble — a light rattle on start-up that the owner rightly didn't want to ignore.
The XJR's 4.0-litre supercharged V8 is a wonderful engine, but from the factory it was fitted with plastic timing chain tensioners and guides. Nearly thirty years on, that plastic goes brittle — and it's one of the most common failures we see on these cars.
From the factory: plastic tensioners that fail
Jaguar built the supercharged AJ-V8 with plastic chain tensioners and guides, and they are notoriously common to fail. As the plastic ages it loses its flexibility, cracks, and eventually lets the chain run loose.
Once a chain runs loose on one of these engines, it can jump a tooth or let go entirely — and with the valves and pistons sharing the same space, that very quickly turns a tensioner job into a ruined engine.
What we found — caught just in time
With the front of the engine stripped down, the chain guides were already visibly cracking. This one was caught at exactly the right moment: a few more months of driving and those guides could have broken up, letting the chain whip against the casing or skip timing.
It's the reason we always tell owners of older Jaguars and supercharged V8s: if you hear a rattle at start-up, get it looked at straight away. Timing chain work done early is a fraction of the cost of the alternative.
The repair
We stripped the front of the engine, removed both timing chains, and fitted a complete new timing chain set — new chains, guides and tensioners — then rebuilt everything with fresh seals and a new oil and filter.
Every stage was photographed for the customer, and the car left the workshop running quietly with its supercharged V8 back to full health.
Timing chains on older vehicles — why owners come to us
Timing chain problems aren't unique to Jaguar. We regularly replace chains, guides and tensioners on older Land Rovers, Range Rovers, Mercedes, BMWs and other classics — engines that many modern workshops simply won't take on.
We're based at Hill Ash Farm in West Harting, just outside Petersfield, and work on older and classic vehicles from across Hampshire, West Sussex and the surrounding villages. Whether it's a full timing chain replacement, a diagnosis of a start-up rattle, or advice on keeping an older engine healthy, we're happy to help.
If your car rattles on start-up, or you've been told it needs timing chain work, get in touch for a straight answer and a fair price.
Rattle on start-up? Don't leave it.
Timing chain problems caught early are far cheaper to fix. Send us a quick description of your car and the noise, and we'll come back with honest advice.