Hello all,

I got my 2005 S Type 3.0 automatic 2 weeks ago and it really is in great shape. 65k miles but it looks and feels practically brand new. There is one little issue though; when accelerating at about 30% throttle and higher the engine RPM flares up about 250rpm, give or take. It doesn't do it really when you initiate an up shift by backing off the throttle.

It doesn't trigger any fault codes. I just changed the transmission fluid and filter/sump (with the genuine stuff) and reset the gearbox software by unplugging the battery for an hour. I was hoping this would help but it didn't (but needed to be done anyway so no big deal).

Does anyone have an idea of what could be wrong? The car does judder a little bit when putting it into drive, and on occasion there is a tiny judder when gently shifting from 5-6 at about 40mph (rarely happens and is very slight, like running over a little bump on the road).

The car is still great to drive but any advice would be appreciated, thanks!

 

I'm not clear if that's a fault but you cannot reset the trans that way. It has non-volatile memory and needs the proper jag tool.

 

I see. I was sceptical when none of the gear change characteristics (not just the flair) changed after the battery was unplugged? Do you think it would be worth the half hour's labour to have the trans reset?

From the research I've been doing I haven't seen another s type or jag with the same issue. I think I'll try the cheap software reset and if that doesn't work then I'll just drive it as it is, it's perfectly driveable and I don't want to take expensive action to reciting a "fault" which is only a minor annoyance.

Hopefully given the fluid/filter change the gearbox is good for another 50k miles.

Thanks for your input

 

You may need an autobox specialist who understands the actual cause.

 

I will probably just leave it as-is unless it gets worse. When you put it into drive it kind of feels that it wants to creep forward too quickly, causing the knock. It feels like the accelerator is still being applied during the upshift. Strange

 

One thing to try?

Has the unit been flashed with the latest software update?
As JagV8 mentioned this will need to done by the dealer.

That was one reason I had the dealer do the ZF trans service on my 2005 STR. They would check and re flash if needed. I was told mine did get updated but to be honest I did not notice much difference.

I had/have the "lurch" to a small extent. The service did help that a good bit. But I drive in "S" 100% of the time and once in a while get a clunk when coming to a stop as the tranny keeps downshifting.
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Thanks, this may be worth a shot. I presume this process wouldn't take any longer than the reset and would therefore still cost half an hour's labour? Wishful thinking probably!

I do wonder if driving it like this is causing unnecessary wear. That's my only real concern, it's perfectly driveable.

The problem is actually less noticeable in sports mode, presumeably because the gear change is quicker and it has less time to flare. I also normally drive in sports mode all the time but I've been told that I can't use it for the next 500 miles (and that I have to drive like my grandma) as I've had the tranny fluid and filter changed. Did you leave it in S after your service?

 

The fluid/filter has nothing to do with 're-flash' or 'clear adaptations'.
You can change the fluid/filter and drive like a complete idiot, it will not change anything.

When you erase and re-install software the TCM needs to relearn the shift points.
Moderate driving is recommended. There are parameters for teaching the TCM proper adaptations.

Most dealers charge 1 hour minimum labor shop time.

If you post your location you might find someone in your area with IDS or SDD to 'clear adaptations' so you can start from 'scratch'. I charge less than half of what the nearest dealer charges but sometimes you just need to visit the local dealer for special software and diagnosis.

bob

 

Yes. Listen to Bob.
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With the recent IDS/SDD it can reset the adaptations AND then they SHOULD drive the car in a specified way to re-adapt as it goes through the gears (driver + passenger who watches the IDS/SDD screen as they learn), the result being no real need to drive any particular way thereafter. (But bear in mind it is learning how you drive so if you drive it like an idiot....)

I have a feeling that not all places will ACTUALLY do it, sadly.

 

Jaguar in their infinite wisdom has removed the requirement to perform the transmission adaptions drive cycle as of 16 FEB 2009. TSB JTB00072 issue 2 has a statement....

"Action: Should a customer express the above concern, reconfigure the TCM by following the Repair Procedure below. The requirement to perform the transmission adaptions drive cycle has been removed."

I would STILL drive the car in a NON aggressive manner for the first few hundred miles.

bob

 

Oh

What a shame! (Thanks for pointing it out though.)

 

Thanks for your input everyone. I think I'm going to get the adaptations cleared in a couple of weeks by my local jag specialist. I still haven't found a single person with the same issue. I have a hunch that it's an electrical issue. I can't help but think that if it was mechanical then the oil and filter change would have altered the nature of the issue at least slightly, but I'm no mechanic!

I could go and fork out some cash to have it looked at and taken apart etc but by the time I'd done that I'd have almost spent as much as a warranted gearbox replacement would have cost, factoring in the £350 oil and filter change I've already done.

Get the chip reset/updated and then if it that doesn't work just carry on driving it. If it goes pop in the future than just replace it. Can anyone spot a hole in my logic?

 

I wonder if it might be a small air leak. At low load it would have a marked effect. Easy enough to watch fuel trims as it does it. (And at idel etc to compare.)

 

Fuel trim seems to be ok. I only checked it quickly though and I'm not 100% sure what I'm doing, B1 and B2 didn't seem to stray much more than 5% at idle, 1,500 and 2,250rpm. I did see 8% flash up but only briefly, I presume that falls within normal boundaries.

It's a tough one to troubleshoot. The only clues from my perspective are a) it affects changes between all gears b) fluid/filter change didn't seem to have any impact, good or bad c) hot or cold makes no difference d) no fault codes

 

Watch (record) LTFTs and STFTs when driving and you get the "flare", too.

 

Another job for my girlfriend on our trip up to Liverpool! She thinks that she's going to sleep the whole trip but I've bought her some felt strips so she can diagnose and fix all of the rattles that the car has developed since I have been driving over the f****** cobbled speed trap next to the office.

Would the vacuum leak not have to occur only during gear shifts if the fuel trims are fine otherwise? (Assuming that it is what causes the issue).

Driving the car in sports mode has pretty much got rid of the knock/slight lurch when going from park to drive.

 

Well... the car's quite clever and does things like reducing torque just before & during shifts, so any air leak will have more effect.

It may turn out not to be a leak but it's cheap to check.

At idle, are the LTFTs under 5 as they should be?

 

I remember finding that out firsthand when I test drove a brand new 2004 XJR. We got the car in late 2003 and I did the PDI on the car. I was driving out the shop door for a test drive when the shop foreman stopped me and jumped in the passenger seat.

He said go and we went to a remote road in the back of the industrial area we were located in. I stopped at the end of the road and gave it full throttle.
The car shifted to second and the car hesitated and then took off again. The guy next to asked if I did that? I said "no" I had my foot in it the whole time.

He noted that the engine backed off a little during the shift.

bob

 

I am leaning towards an air leak somewhere. I had a slight air (vacuum) leak on the rear of the plenum at the brake booster quick connect. It caused the ZF to do some funky things. I replaced the quick connect and immediately the ZF box was back to normal. JagV8 is correct at looking at the fuel trims. Sometimes a slight air leak will not throw a code.
You are in luck, there are a couple different threads I am linking to below, that pertain to your MY V6 air (vacuum) lines. I know for a fact that the OP is not a professional mechanic, but he fakes it pretty good. The first link is every air line identified, routed, and color marked for easy reference. The second is the IMT o-ring check. Within this link is a R&R link to see how you replace the 2 IMT o-rings.


https://www.jaguarforums.com/forum/s...ics-faq-52720/


https://www.jaguarforums.com/forum/s...ck-pics-49214/