S-type auto gearbox jerking
 

Hie all, I'm new to this forum and am a proud owner of a 2003 Automatic Jag S-Type V6. The car has been a joy to drive and my wife and kid are completely besotted with it.

The problem I've recently started having with the car (progressively so over the past month) is that when I accelerate normally the car appears to choke and jerks; almost as if it struggles to engage quickly through the gears. Easing off the accelerator and applying the lightest of acceleration seems to help. This has also started happening when the speedo goes over 50mph; the car jerks as it tries to go over that speed.


I always leave the engine to warm up before driving and there if no gearbox fault light on the dash. I'm quite frustrated by it and am hoping someone out there could provide me with some invaluable information and help me save money before I just rush into seeking a gearbox change. Please help!

Are you sure the gearbox is the problem?

If so the first thing would be to ensure that the fluid level is correct, this is a slightly tricky procedure which you will find in the how to section.

Are there any stored codes?

May have nothing to do with gearbox, meaning possibly a vacuum leak.

Have you checked this thread out:

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

damn norri, just a mere minute this time. :)

As others have said, it's not necessarily a gearbox problem. Have the codes read and do NOT rush out to buy parts until there's clear evidence that they are faulty.

BTW- there's no benefit in letting an engine sit while it's warming up, simply a waste of fuel.

Could be misfires, such as a bad coil.

I had just experienced a cat failure that cause a similar sounding problem.

Symptoms:
- Hard acceleration caused misfires
- Under hard acceleration, I could rev-up the rpm's enough to get into the next gear.
- by backing off on the throttle to about 80%, and no problems were noticed.

Initially for about 6 weeks, no codes were being thrown, until I finally decided to go drive it hard to force the codes to be thrown enough times.

Codes were:
P0430
p0302
P0304
P0306
There was 1 other code that I can't remember.

Anyway, it very well could be misfires from a bad coil.

In my case, the collapsed catalytic converter caused backpressure on bank 2 resulting in random misfires across the whole bank.

Just something else that may help diagnose your problem.

There are no codes being shown at the moment but the engine seems quite sound; there are no shakes and it doesn't sound like its labouring to suggest a coil problem.

I'm enclined to think its the gearbox because this jerking sometimes occurs when taking off at a traffic light, junction or even from a parking bay. Slowly taking off and building speed slowly seems to prevent the car from jerking, as well as taking the foot off the accelerator (when driving) as soon as it jerks the first time (this seems to prevent an episode of jerking).

Fuel trims (at idle & 2500rpm, in P) should rule in/out a bunch of problems.

Thanks JagV8; will give that a try.

Cyberjag,

I have exactly the same problem. We began continuity tests across transmission connectors today.

Hesitation on acceleration when operating temp is reached.
Unusually high revs before next upshift.

We have the code p0733, "Gearbox Fault" message and p1233 - we think the solenoid pack has failed. Your OBD monitors might not have been set just yet, please update us with codes when they arrive.

Check your coolant bottle for pressure - this data feeds into PCM loop. Ours was cracked and leaking - once fixed and driven the fault message was consistent.

Please realise you have utterly different cars! Different gearbox, different PCM, his has a TCM, yours doesn't. His has a CAN bus, not yours. Etc. Please move to another thread. His is a ZF 6HP26 box, yours is Ford 5R55N. The list goes on.

Apologies, thought i glanced and saw 2000 v6.

Have you got anywhere with the vehicle?

This sounds exactly like you have the common "Lurch" found in many of the "03" models, I've drivin one of these and taking off from a complete stop was horrible even when comming to a stop it felt like it wanted to lunge forward. From what i've read on the lurch, it can be helped with some sort of flash or software update some even say a fluid change helped which I don't understand why it would, But still the car shifted fine when accelerating I could hardly feel the shift points, so the common "lurch" doesn't explain why it's jerking when accelerating, My guess is that it's a performance problem than a shot transmission, look for vaccum leaks, air in cooling system etc. You could be low on transmission fluid theres no way to tell on these cars with out draining it and measuring what comes out. :icon_rolleyes:

Transmission lurch!
 

This transmission "lurching" is famous on the 2003 model year. That was really the only year it was an issue. They introduced the new ZF tranny in 03, and had it fixed by 04. I know...I own this same car and have owned it since 2004. Jaguar issued a dealer transmission module software flash update that has since fixed the issue. Might be worth asking the dealer to perform this item for you...may not be costly at all. Mine was still under warranty when i fixed it. But I remember the problem well !! Good luck!
---chris

The infamous ZF "lurch" persisted well beyond the 2003 model year. After all, it's the same six-speed transmission from the 2003 model year through the end of the S-Type run in 2008....

Keep in mind that the software reflash has proven to greatly help some S-Types while doing next to nothing for others. Some owners report that their lurch has virtually disappeared after a transmission fluid drain-and-fill. Others have said that the fluid change made no difference with their lurch....

The ZF is a quirky box, no question about it....

Yep, it's "quirky". The latest Jag Bulletin I know about for it is Feb 2009. Yes, 2009, so I don't think it was fully fixed by 2004 :(

i have a 2006 s type diesel auto when I put in gear the gearbox jerks. this does this when putting in drive or reverse but once driving its fine till I park up again. alsp showing gearbox fault abs fault and dsc fault/ new battery fitted last month

New battery or not , with those symptoms I'd go have that new battery load tested .

new battry cleared initial gearbox fault code abs/dsc still there think needs new wheel sensor. I spoke with jaguar they don't repair gearbox they would only fit new around 3000pounds