I have now had my 2005 STR for about 10 days, since buying on eBay and importing from California. The car is beautiful, and everything seems OK with two exceptions - the steering wheel squeak, and variant #2 of "the lurch".

Thanks to this forum, I have now got 50 ml of the additive C2S 48887, and hope to fix the squeak problem.

Variant #2 of "the lurch" is exactly what I have noticed, whether in Sport mode or not. "When you slow very gently to a creeping halt without actually stopping and then gently try to accelerate - there is a slight hesitation when the engine revs higher, then the gearbox engages the drive wheels with a jolt. This varies from a harsh jolt to snatchy".

Have read many posts on this subject from Forum members, and am hoping to get confirmation that flushing and replacement of the ATF with Shell Lifeguard 6 (M1375.4) will likely solve the problem. However, I did see one post where the problem was traced to a hairline crack in a valve body, and wonder if anyone else had that experience.

 

How many miles are on the odometer? Unless the car is high-mileage (80,000-plus), an ATF drain-and-fill may not affect your lurch issue at all. A ZF transmission programming update at a Jaguar dealership (requires two techs and your car connected to a laptop while in motion) may be a better first option for you. Judging by past reports here on the forum, that typically mitigates the issue but may not cure it entirely....

I would do some further research here before you proceed....

 

If you want to read more, use Search on the word
adaptions
(yes, it's a bad spelling)
or even on
shift strategy

Fair chance a reflash - done properly! - will fix it.

I suspect that it's also important that the engine is running fully right, i.e. (long term) fuel trims are near zero, because the autobox (TCM) and engine (PCM) modules handshake during changes.

 

I've never been confident that a fluid change will cure the lurch. In my case, I can induce type 1 or type 2 just about whenever. The car has the latest reflash but it was not a 100% cure. I just drive around it.

 

Car has done 54,000 miles. After reading up, it seems that I should be doing these things:

1.. Check tranny lines and ATF level to ensure no leaks.

2.. Have dealer use J004 procedure to clear tranny adaptions.

3.. Test drive to see if lurching problem is gone or reduced. If OK, drive normally for about 200 miles, but not in Sport mode, to let tranny re-learn. If not OK...

4.. Either flush or drain overnight and refill with LG6. If draining, consider topping up depleted additive level of tranny fluid that was NOT drained. Check that 6-8 quarts of new ATF were added, and that fluid level is OK.

5.. Repeat step 3.. above. If not OK...

6.. Have dealer reflash tranny software.

7.. Repeat step 3.. above.


Would much appreciate your comments.

 

Can you point me to info inferring that a fluid change alone will make any difference?

 

Mikey - I think it's TSB S307-15v2

 

I'm familiar with that one- it covers the 'whoop' or 'squeak' but that irritant has no connection to the lurch.

https://www.jaguarforums.com/forum/s...hrottle-51476/

 

Looks like it, sorry.

Quite a few people have changed their trans oil and reported it (here / UK forum) much smoother but I don't recall to what extent they may have had or cured a lurch, or whether they even mentioned it.

Checking the trans is filled enough and not too much is necessary, as both cause troubles, but even the check is a bit of a pain and as we've seen not always done right even by those who work in Jaguar franchises.

Got to love the ZF 6HP26 (I gather the 5HP24 wasn't great, either).

 

Well, it's the only outstanding problem with the car, and each option seems to have a 50% chance of success. So, if I go for a J004 plus fluid change plus reflash, looks hopeful for a 100% cure.

If not, I will be contacting Jaguar and ZF for their suggestions. It's just as if the tranny disengages at 2 mph with my foot gently on the brake, and then re-engages with a jolt when I realize there is no need to come to a full stop and step on the gas. Jeez, it's not like trannies were invented yesterday, there must be a solution to this problem.

 

Robin-

There's apparently NO valid references to a fluid change having positive effect on 'the lurch'. It's software flash or nothing.

The 'whoop' is completely unrelated and is only cured with a fluid change.

I'm sure somebody clever could make a video of the two combined and put it on YouTube as a dance video.

 

"valid references" - users don't count?

Regardless, don't omit checking it is filled properly. It's fairly common that they leak fluid and by no means everyone notices.

 

I found none after a search of my own. TSB S307-15v2 clearly only applies to the whoop.

Did I miss something?

 

Well, gentlemen, stand by. I'm going to do it all and, just for research, start with a fluid replacement, then clear adaptions, then reflash. May take some time, but I will report back. I hope I don't end up having to drive around this problem.

 

Yes. I can recall multiple people saying a fluid change worked wonders. I don't know how you didn't read those.

That said, if it were my car I'd start with having the level checked, then the software changes as they're much cheaper and quicker to do.

 

NO is a pretty strong term when used as an absolute. So ... here you go:

https://www.jaguarforums.com/forum/s...-solved-54151/

post #1

Found using local search with "lurch", "transmission", limited to the S-type section as the search parameters.

There are other references for anyone willing to slog through the posts. But only one reference is required to refute NO as an absolute.

++

 

Robinb: Don't read too much into the "lurch"... Bottom line... Does she pull hard through all the gears... Shift good at each one? I'm betting "Yes".

Then it's fine. What you probably will find is that all your work and $$ will make it better but not make it go away entirely. That was my experience.

I think the best advise I can give you is don't fall into the "OMG I bought a POS Jaguar " mindset and freak out at every quirk. These cars are actually very well built. You will run across things that will frustrate you but heck that is true with any car.

I believe that the whole lurch thing is more an attribute of drive by wire than anything else. Also, if you think about it, a computer controls the trans as well. Many different cars that I've experienced have different quirks with their drive by wire systems. A BMW with a ZF trans suffers from weird hesitations, my Chrysler with a Mercedes NAG1 likes to stop and think when transitioning from R to D (kind of scary backing out of my drive). If you really want to see something nuts (at least it was with my Jag), roll to the exit of a parking lot almost stoping then hit the gas to pull out. It will probably stop and think for a moment, just enough to scare the crap out of you.. My Chrysler does that as well. So the reaction is to stomp on it to get going... A big immature OOOPS when you drive a car with more than 300HP.

That said, I would definitely change the trans fluid along with any other service stuff. That is just due diligence for a used car. Make sure to freshen up everything. Then I would get the reflash done along with a full vehicle diagnosis from a reputable Jaguar dealer in your area. Ask them to go over the car with you and to point out areas that may need attention.

Good luck with her... Don't fret and enjoy that wonderful supercharged 4.2.

 

Thanks, I read that post and many others prior to making my statement above. I do regret saying 'NO' (never say never) but it seems that each of the posters in that thread relied on a reflash and fluid change to cure their lurch. If both steps were done then it's hard to say which solved the problem.


From post #1

"I settled on a change in fluid, filter and connector sleeve couldnt hurt. This with a complete memory wipe of the TCU had resolved all the issues."

From post #5

"My Jag certifed tech tried a simple reflash of the TCU first with little improvement. He advised that a "complete memory wipe" was the next level and he was spot on. The results were well worth the money."

Other respondents commented on the fluid change having cured other common ailments, but without mention of having the lurch in the first place.

My interests in the subject is an attempt to substantiate changing the fluid in my own car as the reflash didn't do a 100% job.There are several posts on the board stating that not all cars are completely curable and to just 'drive around it'.

Again- if there's a post anywhere that clearly states that fluid change only eliminated the lurch, I gladly retract my statement above (and schedule my car in for a fluid change).

Thanks

 

Thank you all for your really valuable contributions. Everything seems to point to a fluid change plus a reset and reflash - I found compelling postings from poboyblues that said that a reset/reflash was all that was needed and would permanently cure the problem, and the link from plums has many recommendations to change the pan/sleeve/filter/bolts and fluid.
Right now, I'm full of goodwill towards this beautiful car, so I'll do all of the above. But the last post from JOsworth has made my day.

Robin

 

I fixed ours with nothing but a flash. After about 200 miles of driving, lurch was gone never to reappear.