Whilst cruising in overdrive just over a 3 figure speed (at the nurburgring of course) a porsche 911 came along side for some fun. So I kicked down but the box just lost all drive to the wheels and the engine spun around to the red line leaving me red faced and wondering what TF happened. :headvswal I backed off the throttle and the drive came back with a jolt and clunk then only by smoothly pressing down on the accelerator did it behave a re-attempt to kickdown resulted in the same thing. Note I had covered about 200miles at this point car was warmed up and had driven faultlessly til then at an average 85mph cruising speed.

So.......

What could this be?????

I am in the final stages of preparing for my big trip to the ring so do not want this dangerous issue coming up there (erm again...).

Note my autobox was re-conditioned at Ztech earlier in the year and has run faultlessly since but admittedly I have not tried this at these speeds before.

 

It seems like something could be wrong with overdrive (didn't know if that was included in the re-con) but any expert advice would be welcome.

 

Thanks

 

Chris

Take it you checked the obvious like fluid level? Was the dipstick part way thrown out? Does the oil smell burnt or look brown?

You lose drive if the oil is low.

I will check it.

 

Last time it was ok but I am paranoid about over-filling it as i know that can blow the seals out. I have had the z centre oil-cooler upgrade fitted too.

Do I check the level when it is hot or cold?

What spec of oil goes in?

 

Chris

Check it with the engine running and up to temperature.

Well I checked the level and it was ok. So i checked it hot AND cold exactly as per workshop manual. It seemed a bit down on checking it hot so I added 350ml (hmm better crisper shift and overdrive hooking in smoother and faster) So tested the 100mph kick-down.

D'oh same problem (no drive revved right into the red :confused: )

So...........Added another 350ml even better shifts and now 100mph kickdown all good...........So

 

What have we learned?????? :confused: :confused: :confused:

 

My car has a Zcentre autobox oil cooler upgrade and is lowered could this be the reason why my oil level dipped ok but still needed more oil to work correctly?

 

No it is a fully re-furbed box so...........

 

Confused............

check the TPS voltage and see if the AT kickdown-switch is functioning (with a conzult)

kick down working ok now but technically there is just a little too much oil in the box when i dip it. I have concluded this is because i have got an oil cooler upgrade so the extra oil circulating must be about 700ml?

 

Chris

Whilst cruising in overdrive just over a 3 figure speed (at the nurburgring of course) a porsche 911 came along side for some fun. So I kicked down but the box just lost all drive to the wheels and the engine spun around to the red line leaving me red faced and wondering what TF happened. :headvswal I backed off the throttle and the drive came back with a jolt and clunk then only by smoothly pressing down on the accelerator did it behave a re-attempt to kickdown resulted in the same thing. Note I had covered about 200miles at this point car was warmed up and had driven faultlessly til then at an average 85mph cruising speed.

So.......

What could this be?????

I am in the final stages of preparing for my big trip to the ring so do not want this dangerous issue coming up there (erm again...).

Note my autobox was re-conditioned at Ztech earlier in the year and has run faultlessly since but admittedly I have not tried this at these speeds before.

 

It seems like something could be wrong with overdrive (didn't know if that was included in the re-con) but any expert advice would be welcome.

 

Thanks

 

Chris

I had exactly the same problem! Tps voltages ok! I even stripped it down to check all the connections inside! all fine! changed oil in box and cleaned gauze.

Never did sort it but mine used to jump from 4th(overdrive) back to 3rd(top gear) when i booted the gas at 130+ and red line every time?? take your foot off the gas and it goes back into 4th :confused: still got engine out at mo so i have yet to sort this :o My Box is reconditioned too??! Its from what i can see still attempting to Kickdown when over 130mph which it should not and its not the speed sensor or revolution sensor as they were replaced when the box was out so i can only think its a problem with the Line pressure or AT control unit.or another internal problem (Makes me want a Manual at this time!!):confused:

I have Not tried this in Hold Position but i will when i have the Engine Back in Unless you have tried this before?? Which should eliminate the Kickdown process and keep it in Overdrive once above 40-50 mph

Andy just got in from a 'spirited 250mile' trip back up the country (germany - autobahn of course ;) ) everything fine now. I have concluded that the oil-cooler upgrade means I now cannot rely on the stock oil-dipstick indication and have needed to put in roughly 700ml more ATF. My box is re-conned too and your symptoms were exactly the same as mine.

My oil cooler upgrade is lukes (Zcentre) cooler upgrade, it uses the stock engine oil cooler as the auto trans cooler and then a 13 row mocal cooler to upgrade the engine oil cooling. Sort of like two upgrades in one. Touch wood its now ok. Only other thing i thought it could be is that it is a JDM model with a converter de-limiter so maybe this is screwing with the shift maps. Of course my top-up with oil seems to suggest that was the issue. Totally paranoid about it as alledgedly autoboxes are very sensitive to right oil level being present.

 

Chris