I have never head a supercharger before and I thought I read something before that this may be normal:

When cold, and you keep a constant pressure/speed on the pedal, car surges slightly (engine sound/pitch and revs change a bit).

Is this normal? If not thoughts?

 

Surging is typically caused by a lean condition, especially when cold. If it gets bad enough it can cause backfiring in the intake which is especially hard on a supercharger. I'd have a good mechanic look at it.

 

Here is a link to another post where this is covered thoroughly. In my post is a reference to yet another post where even more documents are found. Read through both threads and you should have a good handle on the condition. One is an S-Type, one is an XK8 similar to your XKR; all the same transmission, same condition.

https://www.jaguarforums.com/forum/s...17/#post368706

Good luck!

 

OK so how does a torque converter fail at 60K? Never in my life have I seen or heard of this? Suppose this is the culprit, 1700$ for converter and 400 for install at dealer plus parts like orings, fluid, etc....close to 2500$

What EXACTLY causes the failure or need to replace and when you replace it wont it just happen again?? Was curious WHAT was the root cause of the failure with such low mileage? They say lining in the bulletin, what changed in the replacements?

Also I have NO CODES.

 

If I recall correctly you can put the transmission in the sport mode and you notice a difference (no surging) chances are it is related to the Torque Converter. I could be wrong but it is worth trying.

 

Well, ZF determined that there was an issue with the torque converter clutch material that caused slippage when the TCC was engaged. That is what's causing your surge. When the slip ratio gets high enough, it will set a code P0741. ZF corrected it, but that still left a bunch of folks out there with this waiting to happen. There was a bulletin for each carline addressing it. Yours is attached.

Cheers,

 

yikes! that's my VIN range.... (bows head and says a quick prayer)

 

$1700 for a converter? Have you considered rebuilt? Should be under $500.

 

Few questions, yes I didn't know they did rebuilt converters, but they are available for $500....

1. If I don't fix it, what will eventually happen?
2. Any special tools needed for the job? JTIS mentions a few but are there homemade tools that can be used? Or is this a dealer job?
3. It does it BOTH in sport mode and regular mode, doesnt matter, so should I try and ECU reporgram/check first?
4. Who else has had this happen to them and what was their outcome?

 

If it were me I would first try a few things before diving into the transmission converter. First I would clean the TB and then add a can of BG 44K to a full tank of gas and drive the car. You have no codes and no confirmation that it is the convertor or not. When was the last time the spark plugs were replaced? As for the tools, any good transmission shop could do this.

 

I just cleaned the TB and MAF about a month ago, was a little dirty but not bad.

This car was dealer maintained and the plugs were changed at 60K per the maintenence schedule (I think thats the mileage I remember?) - now I have 67K on it.

Yes no codes other than the typical P1111 or whetever.

 

1. It will just get worse, and eventually the slip ratio will exceed the threshold and set a P0741 fault.
2. Only to the extent you will have to have some way of holding the engine so it doesn't fall forward when the trans is separated, and what ever you may need to actually separate the two. Aluminum engine, aluminum trans, steel dowel pieces. At times they want to become one with corrosion.
3. In my opinion it is ALWAYS advisable to do the reprogramming, adaption clear and adaptive drive cycle per the bulletin as the first order of business. Just so that is eliminated. Once in a while, you can stop there; but most times it takes the converter.
4. As you can infer from above, you are not the only person that has seen this movie; I think the outcomes are covered as well.

For the most part, you seem to have covered the other bases pretty well, too. So you ought to have a game plan now.

Cheers,

 

It sounds like Steve has you covered. I was only suggesting cleaning the TB, plugs and fuel injectors that can cause hesitation and poor performance but if you have checked it the by all means, forge ahead.

 

no slipping from mine, thankfully...and hoping to keep it that way. I've not heard of any come through these forums, at least on the xk8-r side, though I don't read every s-type thread that is generated either, nor xj8-r. Keep us informed, if for nothing else but to keep you sane, and to share your experience with others who may learn from you.

 

Well I need to schedule a appt at the dealer first.......

 

Never a good time when the car is not operating properly and you do not know why. I hope it is a simple fix.