Hi all, my name is Alan and I have owned a 2003 JRG STR with 50k on the clock since May this year. A very pleased and proud owner. But there is one problem that I don't seem to be able to get any help with. I've been to my Main Dealer who can only hazard a vague guess and searched and posted on the UK forum but no-one has been able to help. So, now its over to you......

From a cold start, once the temperature needle passes the blue cold block and you reach a steady 30 mph, the rev counter needle fluctuates between 300-500rpm and you can feel a slight surge as the revs go up and down. It does the same at any steady speed up to 60mph. Once the temp needle reaches the centre point, the car runs perfectly.

I have had diagnostics done at local Main Jag Dealer and they came up with an old throttle body code but replacing this was an expensive option based on a guess. Other forumers have suggested that the auto box needed re-flashing which the dealer didn't think would fix it. Some have suggested it might be a failed or damp coil. Has anyone had a similar problem and come up with a definitive fix?

 

my torque converter fixed my issues which resembles what you are saying

 

There's a TSB about it, which your dealer should have known!

See http://jim.customer.netspace.net.au/...s_listing.html

You want (note the wrong spelling): tramsmission_surge.ZIP

 

Mine does something similar when it is not warmed up properly. Its not a "surge" for me, it is very subtle, and I only notice it becasue I have a very loud exhaust. Same as you, when it warms up, runs perfectly. I have a brand new throttle body, so I would rule that out, and just had the TCM/ECM reflash so would rule that out as well. I just thought it was normal during warm up, and that I was being too ****.

 

Thanks jagv8, I did find that bulletin and took it to the dealer. That's the one that recommends the re-flash of the transmission. They ignored it. Maybe I should find another dealer??!!

 

Maybe they're not confident they could carry it out properly or that it would be more trouble than they see it being worth - or something. Another dealer would be my thought.

 

Just had the reflash done. Did nothing in RE: to the "surge"

 

The TSB was issued in 2003 so you'd expect your car already to have been given the right software during manufacture!

You did say your symptom wasn't exactly a surge, too.

In case you've got a variant of the lurch (seems doubtful), they'd have to also flash the PCM. And clear the KAM and do the dire (for an STR) adaption.

 

haha ya i guess the TSB was 2003. I am strictly talking about the J004 recall that was just performed on mine i.e. tranny and ECM reflash. I dont have a "surge" but i do have slight fluctuations in RPMS up and down when vehicle is cold, and I am talking SLIGHT. It could be a variation of what he is talking about, therefore, if I do have a variation of this "surge" then the transmission reflash TSB you suggested can be safely be ruled out as a fix seeing as I just had it done.

Im going on record and saying that this has nothing to do with the transmission.

 

thats how mine started, the torque converter started slipping ever so slightly and i could see the rpms moving around on the tach

may not be the case at all, but just forewarning you just in case

 

F@CK

 

I'll second the comments to date...

Torque Converter: I had the same symptoms. While it was in warranty the dealer reflashed - multiple times but never cured the problem. 9 months after the symptoms (and after the warranty expired) the transmission finally threw a code. Replacement with labor is $3,000 and Jag gave me a courtesy discount of $1,000 for a $2,000 grand total. Filed with the BBC since I identified the problem under warranty and did not get any satisfaction, other than the $1,000.

Good luck,
Eric

 

and if it wasnt for eric, id still be scratching my head. and it was 3 g of a repair

 

Im not going to loose any sleep over it seeing as it has been like that ever since I can remember and it last for all of 3 minutes in the morning, only if I am cruising @1500rpm barely touching the gas (will go from 1500-1550rpm). However, I will shoot my Jag Tech an email inquiring about this CODED reflash/different from the TCM reflash I just got. I will try and be somewhat proactive on this and see what can be done before a new torque converter is necessary



https://www.jaguarforums.com/forum/s...hlight=hunting

Real_Tech

Join Date: Jan 2009
Posts: 344



There is a special CODED reflash for the transmission control module that fixes this problem. I'm not certain it is available outside the U.S.

 

I am losing sleep over it as the warranty runs out in 4 days but I have alerted the dealership to the fact that the problem started within the warranty period. Had a look at the threads for the Torque Converter and, you may be right, it could be the early stages but I am not experiencing Lurch 1 or 2 and the gears dont slip or cause a surge going uphill. I would have thought it would still do it no matter what the engine temperature if it was the TC.

Although 2003 registered, it is a 2002.5 build so that relash might be applicable.
I think I will take it to another Dealer in the vain hope that they may be more interested and get the reflash done anyway. Thanks for all your input and suggestions....the mystery remains!

 

There's a TSB for the TC that specifically lists certain VIN ranges for the '03 model year.

My original service adviser had left by the time the transmission threw a code - and the while the TC was not specifically listed as the cause for concern (my fault) but the symptoms were on the multiple repair orders. Long story short, that level of documentation did not hold water after the warranty ended - or with the BBC.

Please do yourself a favor and make sure (especially if your TC falls within the VIN range) that your concern about a faulty/defective TC is specifically listed on the RO. I can't underscore this enough. If listed (or if my original Service Adviser had still been with the dealership) I would have had a much stronger case for a $0 repair.

Finally and in my opinion, the "lurch" has zero to do with the TC - the lurch truly is a transmission reflash and is not predictor of a faulty TC. And like others, my TC acted just fine once it was warmed up or after approx. 3 miles of driving. Again, it only occurred during the first drive of the day and between 35 - 50 mph under a steady state throttle. Almost imperceptible except that you feel the slight surge and then you have to study the tach to catch the ever so slight needle fluctuation.

Good luck,
Eric

 

mine started the exact same way, although over the next 4000 miles it got worse and more frequent. HOWEVER to get it to function normal for a few days, i would drive it like i stole it for a few short bursts..........and waaaaaaaaaala it would be fine for a few days.

I didnt even give the dealership a chance to poke around, i told them the issue, i showed them the documentation for the TSB, signed some autographs for the office people ( you would be surprised as to how this actually works in your favor sometimes) lol, and told them to call me when its done.

 

Real_Tech will definitely know far more about this than I do as all I know is what I've read in TSBs, forums and so on. (And please be nice to him!)

 

was someone NOT being nice to Real_Tech or something???

People sometimes dont realize how much help these guys are to owners. Also the owners can be of help to them also, if they allow it.


You would be surprised how many techs i have helped in my day, and it is a 2 way street though, they have helped me back in the same ways.

The information these guys posess is enormous to an owner of the vehicle, it would most likely be a good idea to NOT **** them off.

 

I honestly don't know if someone (or even several people) upset any particular tech - but there have been a bit more than suggestions of that and some techs have vanished. I'm real glad to see at least one back. You're quite right in what you said.