I've had the same problem. Mine occurs only when the car is cold. Dealer reprogrammed it and said it should disappear after the tranny 'learns' my driving habits. We'll see. . .

 

For sure it is the torque convertor. Had to replace on my car. Job was about $2500

 

Looking at how many people have the same issue, shoudln't there be a recall or something? The TC failing before 100k on the "maintenence free" transmission, sound like a design/manufacturing issue.

 

I'm afraid if the majority of owners reach the higher mileage numbers, you're examples may fall on the outlier of the statistical curve, unfortunately. Recalls are often (but not always) issued for widespread, and more importantly, life threatening or endangering issues. Hunting for 5th/6th gear may not fall neatly into that definition.

 

I agree with veffremov,

It's absolutely unacceptable for an $70k car to have all kinds of transmission issues under 100-150k miles. Us owners are just supposed to fork in $2500 every 30-50K miles for an TC? Complete rubbish.

I just spent $1000 for a new throttle body at 52k miles on my 2004 XJ8, I also have slightly rough shifting from 1st to 2nd gear and although it's gone now (I think just computer learning what to do), I'm troubled to learn I should fear for major repair which I originally wasn't concerned about at all.

I otherwise like my XJ8 and have always liked Jags but to read problems these cars are having early in their lives makes me understand why the depreciation is so friggin' big.

 

I bought my 04 XJ8 with 27,000 miles on it two years ago, and I've had this issue since day one. The dealer reset the TCM before I bought it and it seemed fine. I found out the day after I brought it home that it's an issue only when the car is cold. The dealer has reset the TCM two additional times and it hasn't helped (thankfully for no charge). They also tried cleaning the fuel injectors - no help either. Sounds like from the earlier posts a new torque converter will fix it.

For now I put the car in 3rd gear until it's warmed up and that seems to keep the bucking/hunting of the transmission to a minimum. I'm hoping Jaguar makes good on this problem and issues a recall being that it seems like a design flaw. The car is otherwise fantastic.

 

I'm getting the same issue, only when the car is warm. I was wondering it there is a possibility of it being a throttle body or TPS? Does anyone know if these cars have a idle pass valve like the older BMW's? Mine isn't consistant, so I don't think it's a torque converter. Also, are these drive by wire throttles? If yes, it could be a dead stop in the variable resistor for a drive by wire system. This would also apply to the TPS.

 

Here is the response I got from certified Jaguar technician...

"The surge you are feeling is from the torque converter. There is a special coded access reprogramming that needs to be done. The problem is that if your VIN number is before G13700 then the lastest software is needed to do this. The dealer can read the software in the TCM and contact Jag to see if it has surge software in it. If it does then you need to replace the torque converter."

Basically since my VIN is before G13700 then I may need to replace my torque converter since they have already tried the reprogram several times.

 

I also have a 2004 XJ8 with the same 100-200 rpm hunting at part throttle, but only for the first 5 miles or so of driving from a cold start. It is at the dealer now, and I should have a diagnosis tomorrow. My VIN is post G13700, so I am hoping a re-flash of the TC will suffice....'cause while the car only has 34k it just timed out of Select warranty 3 months ago!!!

 

The low miles and the fact that it only occurs sometimes bodes well for the reflash taking care of the problem.

It's the cheapskate owners that never take their cars to the "*******s" and continue to drive it acting up for the next 20k miles that usually need converters.

 

Any news on how the reflash went? The dealer wants to charge me $150 for the reflash. He also says that it's not essential that I have it done as the RPM hunting is not a reliability issue.

Mike
'04 XJR

 

I don't know about that reliability comment. The hunt is the converter locking and unlocking and it does put extra stress on the converter. That's why I made the comment about people that ignore the problem and continue driving needing converters more often than people that take their cars in for service when it first starts to act up.

I would consider $150 a decent price for the reflash and the required drive cycle test drive afterwards. The original warranty price for this procedure was 1.1 hours so at $120 per hour that comes to $132 at warranty price, an additional $18 sounds reasonable.

 

I got the transmission re-flash today. It consists of a reflash, clearing of adaptations, and an "extensive test drive", whatever that is. It took over two hours to do. The tech told me that the transmission must be cooled first, adjusted/programmed, then warmed and adjusted/programmed some more. Neat.

The transmission is definitely better now. Perfect? I don't know. My ear tells me that there is not a perfect lock between the transmission and engine during conditions under which every other car I've driven normally does. Specifically, if the car is under load at constant speed and I depress the accelerator some more, I would expect the RPM to remain in a fixed ratio to road speed. Instead there is a very slight increase in RPM before the actual acceleration begins. It's so unnoticeable that you can't really see it on the tachometer, but my bionic ears notice. Perhaps this is "by design" as they say. Whatever -- the transmission behaves better now without the wacky RPM bobbing and slip that it had before.

Mike
'04 XJR

 

I hope it clears up your problem. The alternative is expensive (torque converter). The tech at my dealership was so frustrated with his inability to fix it with the software reflash that he took the car home and kept it overnight. That was his version of an extensive test drive. Unfortunately despite his best efforts he couldn't fix it.

 

Mike, the transmission shifts with a different pattern for a few days after the adaptations have been cleared. Keep an eye on it as the symptom may return after a week or so.

 

Has any one determined if there is an adverse effect to not replacing the torque converter? If you live with it could it cause something else to fail? I don't care if it cause stress to an already defective part, but what about the rest of the trans?

 

make sure you specify the "hunting" concern,the reflash for that is different then a lurch

 

I have an 04 with 39k miles on it. Bought it new.
My wife drives the car 95% of the time. I have had this problem since day 1.

Last year I paid $150 for the transmission flash and 3 days later it returned.
It has something to do with its adaptation/learned data.
When I drive it and this problem manifests itself, I hit passing gear and get a few brisk shifts in.

After this the problem is gone for the rest of the drive

 

I have also noticed this 'hunting' when the engine has started to warm, but is not fully warmed up, when driving on a light throttle at a steady speed of around 50-55. It disappears when the engine is fully warm. I didn't notice it today as I did not have the conditions to cause it on my 2 x 45 mile drives. It is very slight, and Yes, I have had the transmission 'reflash', or at least the previous owner had. Actually car looks brand new and drives like it. Now done 4000 miles since purchase.