Originally Posted by silvertonesx24

Thanks for the useful information. I did watch a bunch of youtube videos and there are a lot of ones on the Land Rover 5.0, same engine.

Bottom line, is this something that generally can be fairly diagnosed and addressed as an issue before catastrophic failure? I am pretty aware of noises/smells that are out of the ordinary from my cars and addressing them promptly. The idea of an engine grenading on me randomly BMW-style is not something I like.

Originally Posted by Fraser Mitchell

What does "blown engine" mean ? What does "heads blew up" mean ? Jaguar do not include explosive devices in their engines !



It is clear the main agent, whilst appearing sympathetic, don't really want this job. They will much prefer to do warranty claims jobs where Jaguar pay the bill.

Originally Posted by SinF

Generally, you can hear it long before it goes. While sudden failure is possible, it is likely they heard and didn't tell you, or didn't know to listen.

One of my other cars, a much older car than your XJ, has a V8 notorious for chain problems. To the point that I replace chain and tensioner every 10 years just in case. So I heard many stories of chain-related engine failures. While most of the time the engine is write-off, it doesn't happen every time. Don't immediately assume your engine is toast (but don't start it!) before the scope inspection confirms it. Here is what could happen:

a. Chain jumps one tooth - car runs like **** or stalls right away, but this is fixable! In this condition your ignition timing is off, but everything else is intact!
b. Chain jumps completely, but you only hit one valve on one side. No cam damage, no significant piston damage (just a scratch). This is also fixable, but requires head off and new valves. Still generally cheaper than an engine swap.
c. Chain jumps completely, nothing hits before it stalls (rare, but possible). Buy a lottery ticket.
d. Chain jumps, piston hit valve hard enough to damage cam and/or piston bearings. This is generally not economical to fix as it requires engine-out and pistons, bearings and a lot of other hardware. You do an engine swap at this point, unless car is something unique.

The damage and severity of repair all depends on how hard valve and piston hit. If valve was coming up as piston hits it will likely only cause top-end damage (valve, valve stem, valve stem seal, follower, maybe even cam). If valve was coming down, then it is more likely that both piston and valve could sustain damage. It also depends on how quickly the engine stalls after chain fails. You could have multiple ignitions after chain fails resulting in multiple hits on open valves.

Originally Posted by SinF

Have you run the numbers on doing an used engine swap? I think you might lose less money on selling a running car.

Originally Posted by RPM0507

Yes. Labor to replace engine is $4300. Price on an engine with similar miles to my car, 68,000 mile engine, is $9100. My car was also diagnosed with a leak in the water pump, and possibly needs the isolation kit on the Supercharger. All in, that would be $15,000 to $16,000 for engine swap and repairs. AND, the replacement engine with 68,000 miles would most likely have the faulty aluminum timing chain tensioner guides. So the timing chain service would have to be done as well. I would be MORE than 100% upside down at that point.