This is my first post in this forum. I found what I thought was a lovely 2003 XJ8 4.0 in zircon blue which I paid the normal average price of 5K for.

The car has covered 88,000 miles and all was well for the first few months then the transmission started grumbling and scraping at around 40 - 50 mph... then the engine would stall coming to a halt.

I cleaned the throttle body and MAF after watching several YouTube videos. The car ran perfectly until the day it didn't .... the check engine light came on and the engine cut out a few times.
It was towed to a local reputable mechanic who installed a new torque converter and crank position sensor and put the transmission back in the car.
The car died on the way home, so she was towed back to the repair shop where it was found after a long search that the ECU had fried and there were earthing issues and a few faulty relays.

After a few months the car was ready, complete with recharged A/C. I was over the moon to get her back again, but the scraping noise was still there when putting load on the engine in top gear ( around 1500 - 2000 rpm ).

The euphoria lasted a day and then the car died on the freeway and after waiting a few minutes started again but was stuck in 4th gear which was not scary at traffic lights.
I plugged in my OBD and I have the P0715 code input / turbine speed sensor A circuit and the P 1797 code : neutral switch circuit malfunction.

Does anything I am highlighting point to a common fault, or can anyone recommend a fix that will get rid of these problems. Am I looking at a replacement transmission here ?If so can anyone recommend a good supplier ?

I realize I bought unwisely, but I intend to keep the car for a long time. it does everything I need a car to do and looks fantastic whilst doing it, it's comfortable and quick enough (when working)

Any advice from experienced owners would be greatly appreciated.

Thanks in advance.

Scotty

 

It might be of help, if you could post here a video with the noise the tranny makes. Someone might know it.
Other than that I have a feeling that you would either need a new tranny (transmission) or you might have to have it fully re-build.
I can't imagine that you can find a new tranny, maybe a re-build one. Any random tranny from the wreckers (which is not rebuild) might have the same issue already or soon after.
I most certainly think that the repair shop, where you went, is not capable of solving your problem - if they would know, what they are doing, you would not have the issues now.
A few days ago I came across a very good video on youtube. This guy knows, what he is talking about. This video is about the tranny of a Merc., but he explains the issues an old tranny has, thus it does not really matter that this is not about a Jaguar tranny. Also, the video is in German, BUT you can simply switch on the subtitles in the setting and then select auto-translate into English. The translation is good:


In short, he is talking about dirt/sediment in the mechatronic of the tranny, plus - and this really requires a specialist repair shop - he is talking about compression air-leaks of the "pistons" (I assume they are the moving parts, which do have rubber seals, which are being moved by solenoids). Those rubber seals are old now and there sealing issues and this obviously affects the functionality of the tranny,,, I actually do not know, if there are rubber seals in Jaguar transmissions, nevertheless the actuators (that is probably a better word than pistons) in there might also be leaking or be stuck due to dirt-contamination.

Also, it is very important that someone does that job, who seriously knows what he is doing and has done that before. The guy in the video - albeit competent - repairs Merc-trannys only, as he explains.

 

There is no wise purchase option with those cars, all sooner or later end up with tranny service
Are you sure garage took apart gearbox and looked inside or they just swapped TC and sent you home?
If your noise has anything to do with TC there is also TC valve in the valve body which wears the bore and messes TC operation, symptoms are slow unresponsive TC but who knows, it may also cause the noises
I would look around for someone who does transmissions for living, this box is not hard but i doubt an random garage will get it right so you will only shuttle your car back and forward and pour cash on them for no reason.

 

Thank you for taking the time to write such a comprehensive overview of the transmission teardown and include the video. My car is not driveable at the moment as it is stuck in 4th gear so I will not be able to make a video and post it. The noise sounded like a rock in a brake rotor and then changed into a hum as though something was rubbing on a rear tire.
The differential was serviced and all was good in there, the tires are brand new as are the rotors and pads all round so that's not the issue. the suspension was also renewed at all 4 corners just before purchase.
When I picked up my car from the garage this time, I was told that the car was tested and there was no stalling and the electronics were all working with the new ECU. there had been the earthing issues but they had been cleaned up and the car was operational. I did know that the grinding noise was still there as I had tried to solve the problem with a new torque converter and not immediately stump up for a rebuilt transmission. this seems to have been a false economy as I am not about to put a replacement transmission in the car. it's the only way to have peace of mind.
I will update on progress as it happens.

 

I knew I was in for a rough ride but was trying to keep costs down. I was quoted for a replacement transmission in the beginning but I opted for a new torque converter, hoping this would solve the stalling and the scraping noise..... I was wrong. now I am paying the price.
Sometimes you have to trust the mechanic when they tell you what you need.
I think nearly everything on the car will have been replaced in the past few years except the engine, so it should last me a while.....is the only ray of sunshine in this situation, ha ha.