I would price them at AutoZone, Advanced and NAPA.

Gus
www.jagrepair.com

 

Gus: I tried AutoZone and NAPA...no listings for 2006 XK8.

 

Let me ask you one more thing: Is this surging temperature dependent? Is it worst by far when the car is cold (and even worse when the weather is cold), but subsides to be barely noticeable when warmed up to operating temperature? Or is it pretty much the same behavior at all temperatures?

 

I believe the surging is not temp dependent. I know for sure that it occurs when up to operating temp. Have not really tested it when cold...but I will attempt to this weekend. Usually takes at least a mile to get to an open road...but weekends have lighter traffic.


Will update after my test drives.

 

Pretty much forget everything I wrote above...start from here:


Went for a drive after car sitting all night; the surging begins when there is a slight load such as going up a small hill and just trying to maintain speed around 40 - 50mph. If more throttle, then surging stops.


The more I drove, the less I was able to get it to surge. Took out on highway, held it at 70mph...all was good, although pretty flat road. Put cruise on at 70....came upon a short hill....no surging. Put pedal to the floor..down shifted just fine, took it to 90mph and then coasted back to 75mph, held there for another mile or so...no surging. Got off highway and took a road that is a slight incline for 2-3 miles....held speed at 45mph....no surging at all.


Took another road held 40 - 45mph...nothing for awhile and then heard a "moan" out of the trans and it felt like trans was slipping...this only lasted for 2 seconds and only did it once.


Continued to go up various hills at a constant speed and nothing. Wife was with me and told me many times that it should be surging....but never did.


Also did the R to D and listened for any type of clunk from U joints....nothing....as I expected.


Also I had cleared the P1797 Thursday evening....wife drove to work as usual on Friday and then driving it today (Sat); checked codes after my test drive and no P1797, only the P1000.


So now I am at a total loss. Going to wait until tomorrow morning and see if surging returns with everything cold.

 

Another update: Wife drove car Sunday morning and surging was as bad as ever.


So appears that the surging goes away after 30 -- 45 minutes. Did not check codes yet...will go do that now and update
again.


Checked codes and only got the P1000.


So now what????

 

I will again suggest the Mercon SP fluid change as it has apparently given good results for the people in this thread. It should be a relatively inexpensive DIY job.
See here... https://www.jaguarforums.com/forum/x...03-xkr-147016/

 

Lenny what is it you are looking for? If it is an easy fix I am not sure you are going to find it. The only way to find it is to drop the pan and have things tested and or repaired and that involves replacing the fluid filter and gasket.

The only thing you can do is use the codes to guide you then look and see what you have going on and the only way to do that is to open it up and when you do that you are half way to finding the problem. I am no expert but this procedure has worked for me and many others.

 

To me, it seems to suggest the surging is dependent on the temperature. Also, it seems like your re-seating of connectors and hard reset could have cleared the cause of the P1797 code, hopefully.

At this point, with no error codes and a working car, there are a couple of options:

• Go visit the dealer again and get your software updated. Now that the bus code is gone, they might agree to perform the update. To me, you would have the satisfaction of knowing you have the latest code for the long term, but this is unlikely to completely resolve the issue.
  
• As others have pointed out, visit the thread about the Mercon SP fluid and see if it convinces you that it would be money well spent. The idea is that this model ZF transmission is used on some Ford-branded vehicle, and Ford calls for this cheaper Mercon SP fluid, instead of the expensive ZF Lifeguard 6. Folks have reported a much improved transmission after the switch. I have personally not done this, yet, but I plan to. I therefore have no direct experience. If you decide to go down this path, I would recommend finding a reputable place as there is a very specific temperature-based refill procedure, and having the wrong fluid level is generally considered the source of many ailments.

 

Everything about your ZF 6HP26 transmission issues | BMW Logic7 site


Magnus says:
January 1, 2016 at 6:45 pm
Hello!
I have this transmission in my 2003 XKR.
My problem is that the rpm when the engine is cold goes up and down when driving. The biggest problem is that the transmission makes squik noice when i make a kickdown from gear 6 to 5. The transmission goes in to safemode. I have changed the oil but I still have the same problem. Need your advice here.
Regards
Magnus

Reply

1. logic7repair@gmail.com says:
   January 7, 2016 at 6:03 pm
   sounds like valve body problem or and torque converter, but first you need valve body rebuilt
   
   Reply

 

https://www.jaguarforums.com/forum/s...t-flare-96631/

 

Yep this is not some easy fix. I drove the car more today and it feels like something is not able to hold pressure so it drops out, then pressure builds again and then it drops out...and this cycle just repeats until really warm.


Difficult to believe that with only 58,000 miles the transmission requires repair. Going to see if I can find a compentent shop that knows what they are doing...last one was a total waste!


I would try doing a filter/fluid change and go to MERCON SP but I think that would be a waste of time/money as more needs to be done here.


Thanks to all for your comments and suggestions.

 

Lanny, If you are going to do that, why not get the kit with the new valve in it. Just a small one more step in the procedure.




Wayne

 

There is a mindset that miles are what is important on a car, in some cases that is true, but on these cars often it's years, your car is 10 years old which means depending on previous service some filters / fluids maybe original (ie tranny). Many of us regardless of miles will replace all fluids to get a starting point on condition(new). All fluids will deteriorate over time from heat/moisture/friction. This also applies to all rubber parts as well, sitting is just as wearing as driving to some degree hence you see all the suspension posts in this forum. In the picture of XK repairs tran fluid/filter change is pretty cheap.

 

Not trying to talk you into it, but draining the fluid and dropping the pan might show if there is mechanical damage (metal shavings on the magnets on the pan) or burnt fluid. Also, you could measure the quantity of fluid drained to check if the level was right to begin with. How confident are you that the last transmission service was done correctly? Fluid is about $60, then add a couple hours labor I would guess. I would not change the pan/filter again...

 

Yes take a good look when you drop the pan. If you see shavings or sludge in the pan it might be a good time to reevaluate you situation.

 

https://www.jaguarforums.com/forum/x...07-xkr-155883/
Just more reading up on the experiences of others. And yes I know this is an X150, but basically the same tranny. There are many opinions and many more real car trial and errors out there. Take it for what you will.
My thoughts on your car would be a new or rebuilt valve body included with a Mercon SP fluid change.

 

I can only assume that the Jag dealership correctly changed fluid/filter....as this was done two years ago I think it is a safe assumption.


I talked to a trans shop and was told to bring the car in so they could diagnoise the problem by driving with their computer connected to data log and go from there.


I think this is the best route at this time as the problem needs to be diagnoised and I do not have any means of doing so. Yes I could drop pan/filter, remove/replace valve body and fluid and then hope problem is fixed but that is really all I can do. It needs to be diagnoised....hopefully this trans shop can...and hopefully ALOT better than the last one.


Will be taking car in week of Jan 18.


One thing for sure though, I will be going to the MERCON SP fluid.

 

OKAY...trans shop pulled codes and one of them had to be with the brake switches. I had removed these last year as they were a problem and would turn the yellow light on in the dash...but no light this time...unless bulb is out or something.


Trans shop tells me that the brake switches control the lock/unlock of the torque converter...makes sense....put brake on...unlock TC. I believe the brake switches input to the TCM so it is probably the TCM that is at fault, but I am going to replace the brake switches anyways.
Also going to see if I can talk Jag dealership into reprogramming the TCM without having the new parts in-hand. If it disables the car, so be it....will flatbed it home and let it sit until either a used trans or a new TCM can be found.


Now to find that person that has the brake switches........

 

Can you elaborate on this? Was the switch replaced? Are the other code(s) interesting?

When my brake switch acted up, I got the "Cruise Control Not Available, Check Rear Bulbs" message. May have had a yellow light on, too, I cannot remember. The car did not seem to act any different as I do not use cruise control.

These switches are readily available and are a common failure. As a general statement, you should try and convince yourself that your brake switch is operational before delving into anything more complex regarding the transmission. Best of luck, keep us posted.