When start the car and drive it cold, around 40mph the transmission give a lobbing feeling and it usually takes about 15 minutes or until the car is warm for it to go away. I watch the RPM gauge when this is going on and it goes up goes up and down about 200 RPM.

 

Mine does the same thing. Mine is a 2003 S-type with 72,000 miles. I jam it in 3rd and it goes away in less than 5 minutes.

I changed the transmission fluid this summer. It doesn't appear to have changed it too much.

 

Mine has 71k. Yeah if I drive it hard at first it seems to go away.

 

Same problem here! Just bought a 2003 3.0 with 150,000km (93,000mi) and didn't pick this one up in the PPI or test drives...

Anyway, I found this TSB information...

"TSB S307-14: This Technical Bulletin has been issued to address a customer concern of a surge in excess of 150rpm during engine warm up, at a temperature of 30°C to 50°C and at a vehicle speed in the region of 40mph (64.3kph) to 60mph (96.5kph)."

Somewhat reassuring to see a tsb, but unfortunately, there is no resolve for it posted.

Note: I notice during the "lob", a faint "honing" sound (for lack of better definition) coinciding with the lob. The sound is as though a rear brake was lightly applied. What are the odds that this is a sensor causing the DSC to partially engage and cutting the throttle back?

 

centaur15 is correct. I have attached the TSB that should allow you to fix this. It will require a trip to the dealer. So if not under warranty you will need to pay.

Be aware that a failing TQ (Torque Converter) has also been linked to this same symptom.
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Mine has it, but the word 'lobbing' threw me.

 

Has anyone gotten this issue fixed by way of the TSB stated software update?

My 2005 3.0 S has this surging/dancing tach needle show, along with the 55-70 mph rear end whine that I am working on diagnosing now.

My main concern is the trans surge along with the deep throaty grind/"honing" sound as described by centaur15, as it totally kills the "Jaguar driving experience"

 

I think plenty have but they may not be current posters of messages.

 

No, I never did figure that one out, and like you it did ruin the "Jaguar driving experience".

I did drive 2 1/2 years & over 45,000km's without a real change in symptoms, but in the end I sold the jag, largely because of the "what may become" of the transmission issue.

PS. I didn't ever get the software updates as I wasn't willing to have my dealership (only 1 in my city and they had to transport the car to the next major city for transmission work) risk bricking the transmission module, but if there were other dealers around, I would have considered that before selling.

Hope that helps.

 

Never heard of a bricked transmission. Where did you hear that???

 

Reading the TSB, it does not sound like a software update. It sounds more like a config change through a password protected path.

 

Just ordered a tranny filter pan/oil change kit...so hopefully this along with a hard reset and some soft driving will help it. If not then, I may look into either getting a code reader with Jag software or taking her into the DEALER for some resets/adjustments...tcm, etc...

Am I heading down the right path guys?

 

It was from the dealership mechanics working on my fathers STR transmission. His had slow shifting on top of the same surging that mine had. When they attempted to update the software, his TCM wouldn't take the flash and they said trying anymore could end up bricking the TCM. Not long after this, his transmission blew out with only 50,000 miles.

I don't want to cause panic to anyone else having this 'surging' though, as his transmission never felt 'right' since it came of the lot. It was more than just the surging that I had, his was sluggish (1-3 seconds) between gear shifts on the j-gate, would think long and hard before going into reverse and didn't like to lock in park all of the time.

Also, I just found this interesting thread:
https://www.jaguarforums.com/forum/x...-warmup-95612/

 

I've been on the forums for over 4 years and never heard of a bricked TCM in the tens of thousands of posts so don't fear for that. Sorry to hear what happened but can't see it being the TCM.

 

Lobbing in the transmission during warmup...GONE!

I just finished doing a drain and fill and filter/pan replacement and all is good.
Transmission shifts smooth as butter (no more jerks during gear changes), I've noticed an improvement in fuel economy, and the car seems to have more power!

I noticed that there were a few of the updated Torx 40 bolts on my pan along with an April 2012 pan date stamp, so the tranny was probably serviced not that long ago, but also noticed that the fluid was very dark (almost black) vs the nice golden color. Also after letting her drain overnight, I was only able to get less than one gallon milk jug (3.89 L) out of it...

This issue was likely a combination of very dirty oil (who knows if it was even the right kind), and a low oil level causing pressure issues within the transmission.

My car now has 56,000 miles on it and drives like new

 

Excellent! (Not in a Mr Burns way.)