While driving my 1999 XK8 convertible with 123k miles this week, I had the following problem come up.

The car was warm and running well. I pulled out to pass a slowing car at maybe 35-45 mph and pressed hard down on the accelerator (but not wide open) with the car in “D.” The rpm’s climbed briefly but with no acceleration (it felt like a slipping clutch in a manual), then a loud “clunk” and the car takes off. At that point a “Gearbox Fault” message comes on (I don’t think the CEL was on). I drive it gently for a bit and stop to check the manual to see what it says about that message. I also hook up my Innova code reader and get the following three codes:

P1384 – Jaguar
Variable Valve timing
Solenoid A circuit

P1000 – Jaguar
OBD system readiness
Test not completed

P0734 – Generic
Gear 4 incorrect ratio

So I gingerly drive it the rest of the way home. I had to stop twice and both times when I restart the car there is no Gearbox Fault message and the car backs up fine. I put it in Drive or any numbered and lightly rev the engine to around 1,500 rpm and nothing happens. I rev it a bit higher and hear the loud “clunk”, and it start to move and the Gearbox Fault message comes back on and now the CEL is definitely on .

Taking off (gently) it seems like the car is in a higher gear (though there may have been some slipping. I’m not really sure as I was giving it gas very gingerly.

When I got home I pulled the following five codes (note that I did not clear the codes at my first stop.)

P1722 – Jaguar
Stall speed

P1384 – Jaguar
Variable Valve timing
Solenoid A circuit

P1000 – Jaguar
OBD system readiness
Test not completed

P0732 – Generic
Gear 2 incorrect ratio
P1722 – Jaguar
Stall speed


I started getting VVT codes before the trip (P1384 and P1396) but don’t think those are related.

In searching the forums I’ve found a variety of things relating to these codes, most of which seem to be related to a broken A drum – which I am going to read up on more tonight. It seems that this code can also refer to low fluid level but I have yet to figure out how to check teh fluid lever (since there is no dipstick!) Can anyone point me in the right direction for this process?

Also, I am curious why the first P0734 disappeared on its own and I now have two P1722 codes and what, specifically “Stall speed” refers.

Thanks for any help!

Mark

P.S.: I am in the S.F. Bay Area (East Bay) if anyone has any recommendations for a good shop to deal with this (as I’m afraid I will probably be needing that.)

 

Sorry to hear about your problem. I'm no expert but the first thing I thought of while reading your post was a-drum. The XJ-308 forum has many threads on this topic - search using drum valve body and you will find some good information.

Through this link: https://www.jaguarforums.com/forum/x...-bmw-x5-66718/ and its embedded links you can learn a lot about your transmission.

Good luck. I hope all works out for you.

 

Thanks for the reply and links, Craig. I'll read up on them more tonight.

I'm still hoping someone might be able to shed more light on what "stall speed" refers to. It seems the code can be anything from as minor of a problem as low fluid to a mechanical failure.

I called my local dealer and asked if I were to bring the car in if their scanner might have the capability to narrow the problem down (offering to pay them) but the guy I spoke with was less than helpful!

If no one else has any ideas before then, maybe this weekend I'll see if I can pull the pan and see what I find in there.

 

I have 2 xj v8 jaguars one executive the other sport. They are 2000 and 2001 respectively having done 136,000 miles and 148,000 miles. They are both x308's. I was driving the executive last thursday and it came up with gearbox fault p1722. Took it to the local jag specialist and he said it was either low gearbox oil fluid or a failure of the foward drum. He put car on ramp and checked fluid level underneath next to gearbox. Not sure how he did this as i left car with him. When i went back he said fluid was ok and car needs new gearbox at 1500.00 gbp new or 750.00 recon. I have seen gearbox on ebay for 375.00 recon and am thinking of doing job myself but i am aware it is not going to be easy. Also there are differnt opinions on what gearbox oil to use. Does anyone know what gearbox oil to use??

 

For anyone who was curious, the problem ultimately did turn out to be a broken A Drum.

I looked into several options and decided on a local shop that seemed to have a lot of experience with these ZF trannys and had them do a full rebuild.

It is working great so far and I'll keep my fingers crossed that it will hold up for another 100k+ miles!

 

I'm not surprised Mark, those are classic A,drum symptoms, or in the case of my X5, bearing failure. Once it's fixed, you should be good togo for many years.