Let me start out by thanking everyone on this forum for all their incredibly helpful and quick advice!

Let me continue by stating: I am a 1st year elementary teacher, so I'm very limited on money and time. Taking my Jag to a shop is not a reality for the time being, so I'm trying to do as many repairs by myself as possible; this forum has been a saving grace!

That being said, I've read about how finiky the transmission can become due to a variety of non-tranny issues. So here goes:

-I recently replaced a bad upper-breather tube below the upper elbow which seems to have fixed a vacuum leak that was occurring. I checked the lower elbow, which was fine.

-This was covering a misfire issue. I've replaced all 6 spark plugs and the driver side coils (the passenger side coils will have to wait until December). The engine runs very smooth now and feels completely different in the best way.

Prior to these fixes, the transmission would have difficulty engaging from P, R, or N when cold. There was also a 3-5 second engagement delay. Shifting to 2/3/4/D would not fix the problem. The vehicle would drive like it was stuck inbetween D/N. After driving for a while, reshifting into D would usually solve the issue, and this problem would disappear after the car was warm and running a bit.

-This shift/engagement issue has gradually become worse, in that it may take multiple D/N shifts before the tranny engages fully. Some days take fewer than others. Today I just finished re-adjusting the shift cable, which needed some tightening, but had no effect on the quasi D/N state. It seems that only driving for a while eventually leads to the tranny being able to fully engage, which became much quicker and smoother after tightening the cable.

-Now with the 3 new coils and 6 plugs, and after the car has warmed up and Drive is fully engaged, there is a tranny slip/jerk problem when accelerating from a complete stop and slightly hard shifts. This problem popped up after the coil/plug replacement, not the cable tightening.


I realize that this is a lot of information, and I have found a lot of info in the threads addressing various aspects of these issues, but I thought I would try putting these in one place so I could get much more focused advice based on all the information I've provided, given these tranny issues can be due to a myriad of things.

If anyone could give advice it would be very appreciated, and I'll try to respond ASAP. I would ask that "replace the tranny" not be suggested as the first solution; that's not an option for now. Rather, could you provide least invasive to most invasive suggestions?

At this point, I am considering transmission fluid issues as the next thing to look at. The car just passed 118,111 miles...

 

My findings with both ours:

Trans fluid "drop and refill" about 4 times is #1. With a short drive of say 20kms between those "drop and refills".

The actual gear select cable is mal-adjusted. 22mm spanner on t bheig nuts inside the console. Move then SLIGHTLY at a time ensuring that when the lever says D or R, or N, the trans lever underneath is actually IN that position. This is fiddly, and a tad time consuming, but is a must check.

On the LH soide pf the transmission,under a rubber boot, is teh mystery electrical switch pack. They fill up with oil, duh. Carefully pull back the boot, unplug the connector, and use a contact cleaner solvent (p/pack can) and clean what you can, then reassemble.

Disconnect the battery, leave it that while you have a drink or 3, reconnect and reset whatever codes you need (radio usually) and that will "reset" the ECU, and clear most faults. Mind you, if the root cause of the fault is still present, it will return soon.

That being said, BOTH ours were sorted with fluid changes (8 in all in 1 year), and new plugs, and under manifold couils (whilst it was off made sense). The Black car had oil in that switch pack. The Silver car had cable adjustment issues (slightly more than 1 flat of that nut fixed it).