Huh? What happened to all the other problems? Pretty hard to assist if we jump from brakes to coils to torque converters to seat belts.

 

I hear ya. There's a lot of random stuff going on. The car is a 2005 s type 3 litre.

My vehicle is hunting. I thought it was being caused by the TQ. The dealer mechanic believes it's a coil issue. The hunting is more likely to start after a turn at speed. I don't know if something's loose or just needs to be changed.

I've got a rear wheel squeak that started when a bearing was changed. I was unsure if it was brake related or not. I'm starting to feel like it's something to do with the bearing. Still haven't figured it out.

I started recently getting an airbag/seatbelt light saying that the seatbelt is unplugged. I don't know what triggers it because sometimes it happens and sometimes it doesn't. It didn't happen at all yesterday but two days ago it did. I drove to the grocery store and it was beeping the whole trip there but when I got out of the store the problem was nonexistent. I can live with it for short rides but when I'm driving 45 minutes and it's beeping 4 times every couple of minutes it gets irritating.

 

Hunting may well be an air leak so watch fuel trims / smoke test. With all the posts on here about IMT valves you have presumably already changed the seals...

Seatbelt may well be the switch - just check / replace. Probably cheaper than OE diagnostic machine but go that way if you prefer.

Competent mechanics can diagnose bearings.

 

What does 'My vehicle is hunting' mean specifically? The engine RPM rises/falls? The transmission shifts up and down a gear? The car wanders across the road as though on ice?

If it's the engine RPM rising/falling and happens only during engine warm up, I provided a link above to the most common cause. There's a Jag bulletin that addresses this in detail.

As your mechanic mentioned the torque converters (abbreviated 'TC', not 'TQ') in your year and newer are problem free. The engine coil theory does not fit the description of the fault.

 

I saw someone using the abbreviation TQ earlier in this thread so I wasn't sure if TC wasn't being used for another term like traction control or something.

By hunting I mean the rpm's fluctuate 125-250rpm. This is typically at the beginning of a trip and seems to only happen at speeds under 100km. I've noticed that it'll be fine but if I take a turn quickly (at more than 20km/h) it'll begin immediately after. It seems to be caused more from higher speed turns than the engine being cold but I wouldn't be surprised if it was caused by both/either condition.

I've checked the lines for vacuum leaks but found none. I haven't done anything with the seals yet.

I don't know why the jag tech would suggest an issue with the coil if it doesn't usually cause the rpm fluctuation. He was an older British guy who seemed to know his stuff so I figured he'd know a thing or two.

 

Just like this:

https://www.jaguarforums.com/forum/a...rge%5B1%5D.pdf

 

Yeah that sounds like an accurate description. So I should get the transmission's computer updated?