www.jec.org.uk

Bit of a story to this one I'm afraid but any input or assistance would be appreciated. I have a 2003 STR that has done 49k miles. I can live with the issue but I'd also like to fix it if I can as I love the car and want to keep it long term.

The car has always been very 'snatchy' when pulling away with even a light throttle spinning the wheels. I've got used to it and can ease away without any problem if I'm careful. Anyone new driving it always wheelspins it, including the guy at the Jag Dealer and the local indie who services it - both called it 'lively! Could this be an extreme 'lurch'? Possile though when I drive gently there is no 'jump' at all.

It also has the fluctuating revs (about 150) issue when the engine is warming up. This always disappears after a few minutes, is less obvious when in Sport mode and occasionally doesn't do it at all. There was a recent article on this in the Magazine and it said it was software or the torque converter.

Next, the gear change is generally smooth except for the 1-2 change which always gives a small jolt. Nothing major but obvious and completely different to the other changes, up or down.

Lastly, I think there have been a couple of occasions over the last month or so where there seemed to be an increase in revs without the instant increase in speed, a bit like a rubber band effect. However, this disappeared quickly leaving me wondering whether I imagined it.

To complete the picture, on reading Mike's advice I had the gearbox oil changed in June last year by a specialist in Portsmouth and they also reflashed the TCM with the latest software. Apparently the oil was in good condition with no debris, discoloration or water. Whilst I'm glad I had it done it didn't make any noticeable difference to the gearchange or any of the other issues above.

So, is there an obvious answer or cure? I think all the issues above are connected but I could be wrong. After reading numerous posts on forums, etc. I'm leaning towards it being the torque converter on it's way out. It could also just be a software issue. I'm happy to spend money putting it right but I can live with it and don't want to spend lots of money guessing.

If you got this far and have any ideas I'd really appreciate hearing from you.

Many thanks

Mark

I believe your deduction process is well on the mark. May be a trip to a good specialist gearbox company might throw up something else. A second opinion is well worth having.

Mike

Thanks for the quick response Mike. Any suggestions on who to go to? I used Express in Portsmouth for the oil change.

If it is the torque converter, any idea how much that is to replace?

The guys at Express gearbox in Portsmouth are top guys. Indeed we have had them come to a Portsmouth Region meeting and chat to us about modern gearbox issues. Several of our members have used their services and been well pleased with the outcome.

Removal of the torque converter requires the gearbox to be removed from the car. It is bolted to the flywheel and gearbox removal is the only option. Alan or Wayne Priddy at Express will be able to advise on costs and options.

Mike

Car being looked at on Wednesday, I'll let you know how I get on.

Thanks for the help and guidance

Mark

OK, took the car in this morning, Express were helpful and informative and took the car for a good test drive (and I got a quick tour of the workshop too which was interesting).

Taking account of the oil condition when they did the change (confirmed as very good) their view was that the gear-change was at the good end of the the range they would expect and generally very smooth. With the sensitive throttle they didn't think it was a gearbox or torque converter issue but they also didn't think it was that severe either and not disimiliar to what they see on some high performance cars. We decided the 'rubber band effect' was my imagination until such time as it manifests itself in a more obvious way.

That left the fluctuating revs issue. As it's not such an issue for me personally (and actually goes away completely if you just use manual gear changes for the first few miles) we decided on balance, and considering costs, to let sleeping dogs lie.

So, it appears that my paranoia may have got the better of me. I'm sure the car felt better on the way home as well!

That just leaves me to say thanks to Mike and Express Gearbox in Portsmouth.

Mark