Just feel the urge to share the last weeks' story, it has been interesting with my little green one.

After passing it's 200.000 miles recently (it now has a something short of 323.000km) the old transmission exceedingly slipped in 3rd and 5th, reverse wouldn't engage but sometimes let the car roll forward a meter until it caught, plus the torque converter would let the engine run away when stepping on the pedal without really making the car follow. Then one day the car suddenly smashed in a gearbox fault at 170 km/h on the autobahn that left me stuck in 4th gear until the next rest place, where I was able to reset the error codes. That was the moment of decision, something had to be done.

So given the option to get a ZF factory revised transmission (fast but €€€€), have the transmission revised at the regional ZF station (only €€€ but much slower) I stumbled over an ebay offer of a transmission with only around 50.000km on it, and for a price that I considered worth the risk to not be 100% sure what to expect. Especially because the trans didn't have a a S/N and part list label, because it seemed to come from a test car, so maybe some interesting electronic communication problems to fix later.

Bought the transmission, had it shipped to the ZF workshop, installed, worked like carm right away, I felt lucky, for really small cash. Well, not quite yet.

Two days later the car performed a rather abrupt change from the charming English lady it originally was, to something that was more like an American V8 muscle car. I never believed it to be possible that the Jaguar V8 with its different ignition order can sound like an old mistuned Corvette, but yes, it can. After the restricted performance warning came up all four fuel trims showed +25% saturation. Lots of oxygen that shouldn't be there.
Because I had checked the calibration of my LPG vs. gasoline systems before I knew that originally all fuel trims with both fuels were amazingly perfect around 0.

So I had the workshop tow it back (always 80km one way), and only 2 days to go until Easter, not much time. They found that during disassemby of the catalysts to get out the transmission, one of the exhaust manifold bolts had broken causing a leak that allow air to be sucked in before the O2 probes, and at the same time offer a completely new sound experience.
Took them until end of Thursday before Easter to fix the bolt, but when they returned it the car still had the restricted performance warning. Because it sounded silent and sealed on the exhaust side I decide to take it home, but realized that at low loads/speeds and idle the fuel trims were still running away to approx. +17% or more. Well, still something left for me to look at, exhaust was sealed so now it had to be on the air side I guessed. Fortunately not so dangerous for the catalyst because right or wrong mix, it all goes through the engine and burn in the cylinders, not in the catalyst to melt it down.
After reading a lot here (thanks to everyone who ever touched the topics of the two crankcase ventilations, the EGR and the throttle bypass hose here) I boldly opened the hood and after taking off the engine cover quickly found that the hose between MAF and throttle housing had been pushed partly off the throttle. Maybe someone had been leaning on it during work, I was delighted to have found a prime culprit for my unmetered air.
After the original hose clamp broke when attempting to tighten it (probably was as old as the car) I fortunately still had one of suitable size in the garage from fixing the heating in our house some years ago, normally these huge things don't exactly pile up at home.

After that the car was finally not to be recognized again, purring, smooth shifting and acceleration (yes, taking the risk with the transmission paid off !) and in general a much better behavior that it ever showed since I had it. Maybe the bumps along the way were some sort of compensation for saving so much money on the transmission change

Long story that occupied me for the last weeks to an extend that I had to write it down here.

P.S.:
Immediately after closing the leak the twisted LTFT and STFT started to match (like LTFT -17%, STFT +17%), but the LTFT are extremely slow to come down. After 1 day they are now at L +11% to S - 11%. I expected them to be faster. Anybody know how fast these LTFT values are allowed to update in the ECU data?

 

Great story and even better write up

Quick question...

Did you service the original transmission at all?

 

Thanks, after all that I needed a bit of gallows humor to work it out.

The original trans already had flakes from the bearings in the oil pan/filter, so I never even bothered to have another look at it. I assume the shop scrapped it, or maybe they have a way to return it to ZF for complete factory revision. Revision of it would have cost between 2 and 3 times what I paid for the lucky eBay device.

Besides that the collateral damages are still not finished. Trims keep jumping around like the kids after too much sugar. Tomorrow afternoon will be leak search time

 

In case you mean if I changed oil on the old one, yes, I did after I bought the car. But I have no idea what the previous two owners did.
On my account I would definitely flush oil and change filter every 120.000 km.

 

Preliminary conclusion, old dogs may not learn new tricks, but old cats do.

Thanks to the very detailed descriptions of steveinfrance in his thread Hard Reset and things to to after Battery reconnect I decided that lobotomy was the only way to get my Jaguar home.
So I disconnected the battery, touched the ground to the plus forever, turned the to ignition and start, virtual overkill to get the last electron out of the system and kill every remaining memory. (I assume that disconnecting the battery and leaving the key in pos. II for some time would have been enough, but hey, why take a risk)

Leaving the car dead for the night the first thing after lunch was to rework the lower ground point behind the right headlamp, which looked extremely corroded. I had done the other fron ground points before, but didn't know of the third one at the time. Forgot in whose post here I read of the existence of this one here in the forum, but my gratitude is his! Especially as the lambda probes seem to be grounded by this one.

After following the revival procedure the car started fine, stumbled a few seconds and then started to get her act together.
On first start and idling the LTFTs went from 0 to around +/- 2%.
On second start and idling the STFT followed up to around +/- 3%
Finally the trims were starting to find each other again and not correct each other from an unhealthy distance.

Only thing that worried me a bit was that even though I had around 90°C engine temperature, the LPG system stayed in ready mode and didn't switch over. No chance I'll drive on a fuel that costs close to 1.4€/liter if I can drive on 0.53€/liter ...
On driving away however also the LPG immediately kicked in, completely neutral in terms of fuel trims, so also here the exceptionally good calibration was back.

During the "test"drive (well, more for fun probably) the readings of all FTs were (sorry, German, but top is bank 1, bottom bank 2, left are LTFT, right are STFT):

@ 80 km/h



@ 170 km/h


and @ idle


Said conditions are of course always only the right end of the plot.

Amazing picture for a 15 year old lady with 200.000+ miles.

Not 100% happy with the hanging sections of the lambda signals, may be bluetooth issues to the dongle or maybe the probes are still starting to die. Since I found them all 4 quite cheap on the internet I ordered a full new set and will report back if they perform well.

All in all the car has never driven so well, although I hope it still learns shifting over the next week. The official ZF run-in program to teach the TCM unfortunately is utterly impossible to do on public roads (at least if you firmly intend to live on and feed the family for some more years)

Beer and barbecue will taste even better now in the first real sunny day here since ages.
So if your cat seriously misbehaves: rip her brain out, she'll relearn to be better than before