My STR has 44k miles, and I recently did a gearbox filter change and flush (thinking that was the cause of this issue).

However it didn't help. This is basically what is happening:

When I start driving in the morning, the car will have a pulsating hesitation with a frequency of a little less than a second. You can see the tach jumping up and down about 100-200 RPM. I only notice it between 20 and 55mph~, and it only happens under minor load (either maintaining speed or accelerating slightly) but not when coasting. It's not head jarring, but it's noticeable. The water temp gauge will reach normal operating temperature and it will still do it for a little while, but eventually it starts running fine again. It doesn't do it after work after sitting for 8 hours, but I also live in Florida and it's around 86 outside.. in December..

I talked to a local indy about resetting the adaptations since I just did a flush and I also have the "lurch", but he was hesitant about doing it since it has made issues worse with other customers (but I believe that was with higher mileage cars). I wonder if that would also help this issue?

Does it sound like a transmission problem or maybe some sort of vacuum issue? That's all I can think of currently.

Thanks!

 

When you did a/t flush, how did you determine and set correct fill level?
Plenty of advice here on the "lurch".
Suggest you read and post codes.

Best wishes,

Ken

 

I'm not getting any codes or error messages currently.

As for the fill level, I believe I overfilled at first, so I waited for it to have a very slow drip, and the pan measured approximately 47 C when I plugged it.

 

This is a very well known issue. There's a TSB addressing it which introduces a software flash which works in most cases. S307-14 issued Dec 2003, if I remember correctly.

No flushing of fluids will correct what you're seeing.

 

That sounds exactly like the issue. Thanks so much!

 

There are dozens of TSBs you can download free and read. Well worth it.

 

The shop I took it to isn't finished giving me an official quote yet, but they claim it's a 3 hour job to reprogram the gearbox (not to mention an extra programming fee), and that it would probably only be a temporary fix. It's funny because the TSB says it will take less than 30 minutes. I hope I didn't pick the wrong shop!

 

Sounds like you did. It doesn't take anything like 3 hours.

Go elsewhere...

 

+1

 

Hey, fair go fellas . . . remember to include prep time; their reading time of the same TSB you have been directed to in our Stickies; detailed review time of last night's football game; morning tea and "smoko" time; toilet breaks . . . yeah 3hours for a 30minute job sounds just about right!

Perhaps they will also include the recently announced "Chinese New Year Tax" on top of their other surcharges? IMHO, a truly enterprising enterprise!

Cheers,

Ken

 

If you can let us know if the re-flash fixed it.
Might be a Torque converter clutch too?
.
.
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Hey guys, so the re-flash didn't fix it. I ended up having a Jag dealer do it. He only had me "drive like a granny" for 200 miles, but didn't give me specific instructions. I read about a certain re-learning procedure that should be done after a reflash, but I have feeling that wouldn't have made a difference.

Clubairth1 I read about the torque converter issue just now which might be what I'm experiencing. It's surprising a car with 45k miles would have this issue, but it is 14 years old now. I guess I'll save up and consider a new torque converter eventually.

 

If they use the normal jag tool (IDS/SDD) the relearn is done before they give the car back so no need to drive any particular way.

 

Oh I see.

The first indy shop that wanted $600 for a reflash did say the gearbox had slightly high pressures. His theory was that when the ATF got to running temp, the pressures would drop which is probably why the issue went away after being driven a little bit.

 

It seems that you fall into a small group where the software flash didn't help. Welcome to the club.

The explanation I remember reading years ago is the root cause for the problem (and the inability to fix it in all cases) is a certification requirement to reduce emissions by having the transmission warm up as quickly as possible. This is partly accomplished by applying the torque converter clutch via a software command but what works in theory does not work in practice.

I've just gotten used to my car doing it and much like the lurch, just drive around it.

 

That's unfortunate, but not a huge deal. I only worried about it shortening the life of the gearbox, but otherwise I can live with it.

Thanks!

 

+2

 

I'm in the club too ! But without the lurch .
I inherited my club status with the car ,
Mine has had three re flashes and two trans flushes according to my service history .
and I have also done a fluid and filter swap , to no avail .
It doesn't seem to damage anything as history shows my car has done it for over half its life and over 100000km , still otherwise working perfectly , and I think I'm privileged and lucky to have the surge without the lurch !
I find for the 6 or so minutes it takes to warm up selecting 4th gear sorts it out .

 

My '06 STR has it also. Mines usually gone after about three minutes though. I've got 107K miles on her and still runs like a top. Still trying to track down a small vapor leak code. Other than that no issues. I've had the car for eight years and the only thing I've had to replace is the battery, O2 sensor and a thermostat. I can't believe how reliable this thing is.

 

My XJR started doing the same recently as well. It gets annoying in morning traffic though. Sigh.