i have a uk spec twin turbo auto..and all of sudden its started dropping out of drive..ie will suddenly free rev and then clonk as it re engages. sometimes it will reverse ok but not engage drive ?...oil level seems ok ie over the indicator on the dip stick and no warning lights are coming on?

Plus when i floored it whilst doing 90 or so the engine just revved right up and nothing happened in the forward propelling area???

any ideas?

Smell fluid, check level with engine running in park and warm.. Sounds low on fluid. Does it buzzzz?

Smell fluid, check level with engine running in park and warm.. Sounds low on fluid. Does it buzzzz?

 

 

yes it seems to on start up?

Think it could be torque converter on its way out. If oil smells of burnt sugar and is a dark colour it wiil be the case.

Smell and re dip. and report back maybe?

Porbably a longshot but my auto box did this once when my speed sensor was packing up. I came out of a fast bend over a humpy bridge then floored it - nothing revved up to the redline and coasted to a halt clearly in neutral even though I was in Drive. "torque converter shot" was my first clear thought. I stopped the car dipped the trans oil and it was in great condition (only recently changed) I then re-started the car and it worked faultlessly except the shifting pattern when fully floored did not shift into top unless I backed off and re-floored it. :headvswal As I then replaced the speed sensor that weekend the box has worked faultlessly since. I therefore assumed the speed sensor input is crucial to the box working and that the ECU plays a part obviously............If not the torque converter look at the electronics too.......

Forgot to add........Does anyone know exactly what the HKS autobox upgrade :bow: does I know it is about £1500 so I assume there is some serious work in it

Thanks for the suggestions but.....

well tried the warm test and the levels seems ok...the oil is also clear...took it (tried too) for a run but when you put the box under any load the gear change is more like someone thumping the cog with a hammer and it lunges forward.

anymore suggestions anbody? eeek!!!