I haven't driven the Jag for several weeks due to a surgery and my son borrowed it this weekend while he was in town for Thanksgiving. The short story is that he drove it for at least 10 miles while the car was making a noticeable noise from the engine. I haven't been outside to hear what it sounds like yet but my father-in-law said perhaps a piston rod bearing and I threw out the thought of a rocker arm or pushrod. What would the usual suspects be in a case such as this?

Frank

 

There are no rocker arms, or push rods on the engine. It has overhead cams and they won't cause a knocking noise. If it is knocking loudly your friend is probably right.
The usual suspects for low oil would be rod or main bearing.

 

Big end bearings, which means a new engine. They don't like to be run without oil.

 

Give Dr Dome a shout for an Engine.
He is not far from us and he should be able to hook you up with an engine and any other parts you need.

 

What do you mean by low oil? Low quantity? Low pressure?

Pretty hard to give a diagnosis when you've not looked under the hood yet.

 

As mentioned above, no rocker arms in the x-Type.

I ended up having to replace my engine. Here's what it started as:
I parked the vehicle immediately after hearing the ticking, maybe drove 1.5 miles home and the car sat for over 2 years for me to look at it.

Drove it to Jaguar after I hadn't torn it apart in over 2 years. After about 25 total miles since I first heard the tick, this is what it sounded like:
As mentioned, engine needed to be replaced. It is now running just fine.

Good luck, and inform your son to stop driving a vehicle when it makes strange noises.

 

Thanks 91Stelthes for the videos. I listened out the door when the guy from the garage came to pick up the car and it sounded closer to the second video than the first. They also said new engine would be the recommended fix as they said that chasing down the bad parts would probably end up costing more and taking longer. I spoke to my son after he came home and told him that as soon as he hears any engine making a strange sound that he should pull off the road and turn it off, as it's usually a simpler fix at that point that it will be after driving for any length of time. Ironically the reason that he borrowed my car is because his was getting the engine replaced...guess who will not be borrowing another vehicle for a time...

Frank