Hi there,

it's been a while since I've started the "epic fight" with my XJ gearbox. It all started back in December 2011 when I posted this thread: https://www.jaguarforums.com/forum/x...82/#post441237

Well after a very long stay at my mechanic's workshop the transmission was absolutely and completely disassembled and then assembled back again. The strangest thing about my story is that any single piece inside the gearbox was good as new! Including the A-drum - no scratches, no signs of worn or anything else... to be honest the gearbox is looking more like to be 5000 miles instead of it's actual 150'000 miles.

Nevertheless after inspecting every element inside we decided to assemble the transmission, put it back on the car, change every gasket and seal on it, change the oil and the oil filter and try to run the car again. Everything was perfect until the moment of "starting the car". The fuel pump is pumping, the car is on, but it doesn't want to even rotate the starter... It only shows up on the dashboard "High Gearbox Temperature" but as much as I found about this - it seems that we have broken a temperature sensor, but this shouldn't affect the start of the car?!?!?!

I expect any advice, because it's been almost a month since I can't use my precious car

 

Does the starter attempt to engage at all? If not, I wonder if that temp sensor is preventing the car from starting as a safety feature? Hopefully a tech or someone more knowledgeable than me will come in with an answer on the no-start situation as it relates to the temperature warning.

I just finished putting a replacement transmission in my 98 XJR, but I had better luck, as the car started up and ran without throwing any codes.

Have you tried clearing the code and giving that a go, or maybe a hard re-set?

If the starter is trying to engage.. it may be more ominous. I was warned by the transmission parts supplier that sold me the cooler flush to be careful not to wedge the torque converter when bolting it in. It would have to be really out to stop the car from turning over, so that is probably not the problem. I assume you have to be a bit heavy handed to do that, but he told me he has seen it lots, where people tear the pumps up by not having the converter fully home and torquing up the mounting bolts. I made sure I could spin mine by hand before bolting it onto the drive plate and pretty much turning the bolts in by hand.

Hope you don't have to pull the transmission out again... although you will be good at it now!

Good luck

 

No, the starter does not engage at all, meaning that the car's computer is preventing the car from starting, meaning that something is telling the car it shouldn't start the engine! The question is - what it is

My mistake! I have just spoken with the mechanic - the starter is actually rotating, the fuel is entering the engine, there is enough charge on the battery but the car doesn't start at all!!!

Yes we did cleaned through the OBD all the errors, because there were a lot thanks to the problems that brought the car in the mechanics garage. But we haven't tried to read or clean errors on the transmission itself... Today we are planing to do this...

Still waiting for some advices Thanks for your fast reply JWT - I appreciate it....

 

Yesterday we've checked all the connectors on the transmission - everything was ok. And still - can't run the car... we've tried to do engine flush, we've put a new battery - nothing helps. The starter is just engaging, the fuel is flowing (even the spark plugs are wet) but no start at all

Anybody?!

 

There is a "crankshaft position sensor" on the gearbox-engine joint area, reading inputs from the flywheel, to coordinate the ignition. On some cars(or all cars,I think) if it is unplugged or damaged the car fails to start.

 

Actually there are two sensors... And we did checked them - they seem to be in good condition. The only way to be sure that they are working is to measure the values they are returning. Can someone provide the default values for this sensors?!?

 

Estilian:
In order to "measure the values" for the ckps is to use a scope and you are looking for 26 or 27 pulses per rev, as I recall. The static resistance may be in JTIS. Your statement that there are two of them makes me wonder what you are actually looking at. There is one crank position sensor, (on the bottom of the engine), and one or two crank position sensors on the top, depending on the engine. What engine are we talking about, anyway? BTW, I THINK you would not get fuel pulses without the CKPS, but I am not sure. I assume they have looked for pincjed wires and blown fuses in the engine control circuits,
Good luck, and keep us posted.

 

Thanks for all advice, but unfortunately, as my mechanic said - the worst had happened to the cat... After all the problems I had in the last month right now the car is in perfect condition, meaning that the transmission is working as it should and even smoother than ever; the engine starts perfectly; no error codes at the ECU at all!
The worst thing about all this is that the car somehow repaired itself without any actual work done by us, except for the total disassembling and re-assembling of the transmission (no repairs had been performed except for the oil, filter and gaskets change) and some procedure my mechanic did for starting the car after reading some threads in this forum. He said that the engine cylinders had "choked" - I don't know what this means, but I don't care as far as this is not related to some malfunction.

Well, the result of all that happened - I spent a lot of money for repairing the BIG Nothing... I couldn't use my cat for about a month, including during the holidays around Christmas and New Year... I had my car back in almost the same condition I left it back in December and no one can guarantee me that the problems won't reappear in the future!

 

Aside from haunting by supernatural spirits, I would guess that some connector(s) got dirty and provided intermittent contacts. Taking everything apart and reassembling also exercised the connectors and scraped away oxide and corrosion on the pins. Just a guess...