If You Want To Buy A Cheap Jaguar, Here’s An Engine You Should Probably Avoid

In the used car horsepower-per-dollar wars, five-liter supercharged Jaguar and Land Rover products seem incredibly appealing. You can pick up an XFR with 510 horsepower for less than $20,000, and it’s still a handsome, well-equipped, and seriously rapid car by today’s standards. However, cheap things are often cheap for a reason, and the early third-generation AJ-V8 engines in XFs, later XKs, final-generation XJs, and several Land Rover vehicles aren’t exactly known for staying in time forever.

Yes, these five-liter V8s had timing chain system issues, notably premature guide wear that can result in seriously expensive repair bills. Let’s dive into what goes wrong here, along with one supercharger-related bug-a-boo, and smart ways to shop around the timing issue.

Over the life of the third-generation AJ-V8, Jaguar Land Rover used two different timing chain designs. Exceptionally early AJ133 V8s got a 6.35 mm pitch chain made by Tsubaki, while everything else got a chain with an 8 mm pitch made by INA. While some will argue about the reliability of either chain system, the fact of the matter is that the primary culprit in five-liter AJ-V8 timing system problems usually aren’t the chains themselves. However, it is worth noting that the Tsubaki chains are no longer available, meaning that if they get damaged, all sprockets and hardware will need updating to accommodate INA chains. Not fun.

A technical service bulletin for 2010 to 2012 Land Rover models with five-liter V8 engines reports of a rattle that “may be caused by wear on the timing chain lever, resulting in reduced tension on the timing chain.” That’s a very hush-hush way of saying JLR used a design in which steel timing chain tensioner pistons would ram directly into aluminum timing chain guide rails, and since steel is harder than aluminum, the tensioner pistons would eat into the rails and lead to slack in the chain. The fix? Pull the front of the engine apart and replace both the rails and  the tensioners. On a 2011 Land Rover LR4, a timing job calls for 18.4 hours of book labor, making for an exceptionally expensive job.

Mind you, worn timing guides aren’t the only route through which a five-liter Gen III AJ-V8 may jump timing. Imported car specialist JE Robison Service out of Springfield, Mass. reports of another failure mode.

We have also seen slipped chains in engines whose the oiler tubes have been torn off by contact with the running chains.  The only way that contact could happen would be for the chains to go slack on overrun, which again suggests tensioners are failing on their own.  If an oiler lube (several inches long) got pulled into a timing gear, it’s not hard to imagine the chain slipping a few teeth in passing.

While it seems from the published technical service bulletin that Land Rovers are affected while Jaguars aren’t, reality doesn’t quite reflect that. Multiple Jaguar owners have reported timing system issues on their five-liter V8s, including one owner who tore down the front of his engine and found it had jumped timing despite previously receiving updated chain guides and tensioners.

Here’s a Jaguar XFR owner reporting diagnostic trouble codes P0016 and P0017 — camshaft position codes that often indicate jumped timing.

And here is one of the worst-case scenarios, an XKR owner reporting that their timing chain jumped hard enough to bend several valves.

Mind you, timing chain rattle isn’t the only rattle to worry about on supercharged models. According to a Jaguar TSB, a “clatter/knock/rattle” might occur due to “torsional isolator and/or the torsional isolator spring support shaft wear causing excessive backlash in the supercharger drive.” The fix for this is a supercharger isolator kit that takes between 3.4 and 4.7 hours of labor to install depending on model, although if there’s any blade wear or supercharger bearing wear, the whole supercharger will need replacing.

So what can you do if you still want a V8 Jaguar or Land Rover but also want to mitigate the risk of expensive timing-related repairs? Well, you have a few options. The 4.4-liter engines found in 2005 to 2009 Land Rover LR3, Range Rover, and Range Rover Sport models, along with the supercharged 4.2-liter V8s found in 2004 to 2009 XJRs, 2003 to 2009 XKRs, 2008 to 2008 S-Type Rs, 2008 to 2010 Jaguar XF SCs, and 2006 to 2009 Range Rover Supercharged and Range Rover Sport Supercharged models are substantially more robust and extremely unlikely to run into any timing system issues. In addition, five-liter supercharged models built after 2015 should feature updated parts that are more robust, but as we’ve learned, not completely failure-proof.

Another option, and this both sounds and is crazy, is to build timing guide and tensioner replacement into your budget and replace those items proactively. Figure around $7,500 to have the job done at an independent specialist. That’s not small change, but if you really have your heart set on say, a Jaguar XJ Supersport, it’s best to not be caught by surprise should issues arise. When they work, they’re lovely cars, and the cars we love make us do funny things. Besides, it’s not like BMW’s N63 V8 was a bastion of reliability either, but that’s a story for another time.

Images: Jaguar

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