From my very first post on my car and the problems I had with the transmission, I've never been able to fix it but am getting closer.

I've learned that it has had the fluid changed at some point. I don't know what fluid was used or when but it wasn't the correct recommended zf fluid. Following the pink fluids origin and finding a different type plug in the fill hole is the proof of prior work.

So that is a good and bad news mix. At least I know the transmission was attended to but I do not know why. I would've taken care of the tensioners first as that's a known issue but it wasn't as I came to learn the hard way. Must've been a reason they did that and seeing I have an updated thermostat housing may be part of it? I'll never know what went on.

Back to the limp mode when I first start the car in the morning and the coolant leak which has gotten worse. These might be related.

If the coolant is leaking onto a connection it may cause the P0715 turbine speed sensor code I'd found. A real mechanic with a jaguar specific computer program found a previously unknown "failure to communicate" or somesuch error between tcu and ecu and told me it could be a bad connection and agreed my coolant leak could cause it. They would not perform any transmission services until I fixed that error.

I had replaced the battery just to be safe as I was told about the problems low voltage could cause. Mine was resting at 12.38v so I replaced the battery. Now I'm a solid 12.6v and good there.

Thinking about why would multiple starts and code resets, upto 5 times but usually four, finally get the car to run right? What is happening to solve the issue for thee day?

Thinking maybe its warming up and drying off the dirty connection I tried a new approach and let the car warm up prior to driving off first thing. I also ran through the gears to distribute fluid.

Thee results are better. The first time only one reset was needed. 2nd time none but I'd let it warm up for 15 minutes and coolant temperatures was at or above 190. So it looks promising.

However the coolant leak has increased and I'm still trying to source the exact location. What I can see is a good amount running out right above the transmissions gear selector mechanism and/or a bit forward of that spot. Hard to pinpoint but have noticed the leak increased as the car warmed up then slowed down? What's that about?

Looking at the side of the car part of the leak was lining up with the reservoir tank. I had just topped it off using 2 cups / 16oz of fluid and was about to check how much it had just leaked during my test. Could it be its that tank emptying out which is why the leak slows down? How much does that reservoir hold anyways??

Unfortunately my tests have stalled by the hood release mechanism breaking. I can't check the fluid loss or continue on until I resolve that matter. See my new post on that subject and tell me if I'm doing it right. Appreciate it.

So I'm closer but have not resolved the issue. Its interesting that warming up the car helps in its current state which is why I'm posting this. I may be onto something or just out in left field hopelessly hoping??

Anyone ever been down this road before?

Thanks to everyone and the good advice I've had. I'm following all of it and going at it slowly and methodically but it is wearing on me. This issue is two months old already. I thought it'd been fixed a long time ago but it just keeps getting weirder.
Building a lift was necessary to gain a better viewing point. That slowed me down.

It's never nuthin ### rtp

 

Not been following your journey, but felt a few suggestions may or may not help!

With regards the timing update, you can eyeball confirm if it's been carried out by pulling a cam cover, I prefer the opposite side to the dipstick, seems easier.
A total of 20 mins to undo the very lightly torqued bolts, take a few pics of the primary chain tensioner and chains etc, then button it back up as Job Done.

The transmission:- they do have issues, so a new to you car could benefit from all fluids changed - a rolling list to tick off - then you have data points for service intervals of your own.
Correct fluid, filter and possibly a transGo kit installed again for piece of mind.

Coolant leak - there are a few parts than can cause a leak in this area, the Octopus hose that sits at the rear of the engine on top of the transmission bell housing, res tank as you suspect, they have a welded plastic seam that can crack expand and leak... Also, the 2 'valley' hoses that run down the centre of the engine can leak and appear to pool at the back of the engine. A good torch, hot engine may ID it.

 

Are saying this tank could be expanding and leaking then contracting and stop leaking? Or that the expansion could cause a crack that leaks?

Follow my thought? The stop and go leak i get. It'll only leak under pressure which is apparently whats happening.

I suppose a pressure test is a good idea. Might not be the reservoir but it may help locate the culprit?

Thanks for your time!! I do appreciate your input and guidance. I'll get this fixed eventually.

Ouestion, if I have to resort pulling the intake manifold what other parts need to be changed while I have the access??? I'm assuming any and all hoses, vacuum line and in my case maybe the upper bank driver side o2 sensor thats giving me the 1647 code? Hopefully the o2 sensor can be gotten to then. Anything I'm missing?

Thanks again.

 

I've seen it stated that it's worth changing the knock sensors as they are under there & can't be accessed normally.

 

Normally aspirated 4.0 engines have an intake manifold with access to the KS between 'runners'.
SuperCharged engines are altogether different.

 

Ahh, I was thinking of supercharged ones. Thanks for the correction.