2010 Wagon Violent gear change when cruising at 100km/h

[Denno]

Hi all,

Been away from the forums for a while, but can finally come back now that I've got a Commodore again .

I recently purchased a 2010 Wagon from a dealer, and it's been driving fine, however on the weekend was the first time I took it on the expressway.

Cruising along at 100km/h, revs sitting just under 2k, if I gently place my foot on the accelerator to get the car to change down a gear and speed up, I instead get quite a violent gear change and the car aggressively pulls back, before it changes into the correct gear and accelerates like nothing happened.
I don't think the issue is changing down to too low a gear, because the revs don't go up. I seem to recall a bit of a clunking sound when it happens also. It's not like the foot is taken off the accelerator either, because the car actively pulls back, rather than just rolls along, like aggressive engine braking (but as I said, revs don't go up).
I'm still within my 3 month warranty with the dealer, so I think I just need to call him up and see what he can do about it, but does anyone have any ideas what these symptoms might indicate?

Thanks!
Luke

 

[greenacc]

Email them about it as well as call so you have some proof of the issue!!
Hopefully it just needs a service, aka new fluid. But your description does sound eerily similar to how my VS used to do strange erratic things when the TPS had pooped itself and was sending wildly inaccurate throttle readings.
Service would be the first thing on my list.

 

[aussie4life]

Is it the 4 speed or 6 speed auto?

 

[Denno]

The listing for the car said it's a 6 speed sports automatic

 

[Skylarking]

I'm still within my 3 month warranty with the dealer, so I think I just need to call him up and see what he can do about it, but does anyone have any ideas what these symptoms might indicate?

The symptoms indicate something isn’t correct and the issue should be fixed by the dealer under your used car statutory warranty. So best not to delay notifying the dealer of this problem.

It‘s also best to document your correspondence in a written form in case you have issues with the dealer not fixing the problem. Keep it short and simply, just reference the fault symptoms you experienced, the conditions around the fault and whether i5 can be reliably replicated (going up hill @ 100pkh and trying to gently accelerate, etc), the fact you’d like it repaired under your used car statutory warranty and requeste an appointment where you can present the vehicle to be examined and the fault corrected.

Email is best as you have a record of the notification. It’s even worth keeping records of each and every contact you make with them, be it via phone or via personal discussions. It may be pedantic but following up phone call with an email summary of the conversation doesn’t hurt either (though dealers do get peeved as they don’t like paper trails)…

As already mentioned, it could be TPS but also accelerator pedal position sensor or something internal in your gearbox… but really that’s for them to determine the cause and correct it… Their first port of call is to check for any fault codes… but also drive the car in the conditions that can replicate the fault.… hopefully they can identify the root cause and fix it…

Let us know how it goes.

 

[Denno]

Thanks for the replies and the encouragement to get in touch with the dealer. I have done so now both by calling and email, just have to organise a time that suits both of us to get the car looked at.

Will keep everyone posted

 

[Denno]

Finally got the reason for the issue from the dealer, needs a new gearbox. When he rang me to tell me, he said that he could get it "fixed" for around $400-500, but it would need to be fixed again in a couple of months (when the car is out of warranty). In order to properly fix it, it's around $1500 for a new gearbox. He then asked what I wanted to do, and obviously I want it fixed properly. He then asked how much I could contribute to the repair cost. I was a bit taken aback by that, and said that I could only possibly do a couple of hundred dollars.

Anyway, my next question is, am I at all liable for any of these costs? I feel like I'm not, but the fact that he asked me to contribute has me wondering..

 

[Lex]

it's around $1500 for a new gearbox

A lot more than that for a new transmission. I just re-read your earlier posts. Gearbox is manual. Trans or transmission is auto.

For that price l'm guessing that is for a used trans? Plus labour?

 

[Martbar]

Finally got the reason for the issue from the dealer, needs a new gearbox. When he rang me to tell me, he said that he could get it "fixed" for around $400-500, but it would need to be fixed again in a couple of months (when the car is out of warranty). In order to properly fix it, it's around $1500 for a new gearbox. He then asked what I wanted to do, and obviously I want it fixed properly. He then asked how much I could contribute to the repair cost. I was a bit taken aback by that, and said that I could only possibly do a couple of hundred dollars.

Anyway, my next question is, am I at all liable for any of these costs? I feel like I'm not, but the fact that he asked me to contribute has me wondering..

I would have thought that it would have to be fixed properly.
Asking you to make a monetary contribution for the repair seems like he's trying it on. It's his problem and its got to be repaired to an acceptable standard and the cheaper repair lasting for a couple of months is not an acceptable standard. Good luck.

 

[greenacc]

Definitely sounds like someone is trying something on here. And how much can you pay for us to fix your car under warranty?
I'd want it all on paper exactly what I was being asked to pay for before handing over a single dollar in this situation.
You don't want to find yourself in the situation where you pay for it to go in for a new transmission and get it back with the same trans in it filled with new fluid and a bottle of transmission 'fix'.