prevention/repair of common issues Z4 35i

[Busterboo]

Right not 10x times but few times longer... see this: https://www.youtube.com/watch?v=RuNNqh8-jkw. my garage explained the same

And you take this chump seriously?

Yes as my garage who do performance cards told me exactly the same. after changing oil in my gearbox its changes gears smother

It's called 'the placebo effect' and 'how garages make money'. :wink:

 

[enzed4]

And you take this chump seriously?

Yes as my garage who do performance cards told me exactly the same. after changing oil in my gearbox its changes gears smother

It's called 'the placebo effect' and 'how garages make money'. :wink:

So are you saying don't change gearbox or DCT fluids? My 35i is on 78,000 km so wondering whether to get the DCT done.

 

[flybobbie]

I have changed the oil in my manual gearbox twice, never really made any difference.
Friend changed the auto oil in his high mileage car (not a zed) and it buggered the box up and wouldn't change gear properly.
Was living in the states and was due to come home so just scrapped the car.
He was warned not to change the auto oil.

 

[Busterboo]

Yes as my garage who do performance cards told me exactly the same. after changing oil in my gearbox its changes gears smother

It's called 'the placebo effect' and 'how garages make money'. :wink:

So are you saying don't change gearbox or DCT fluids? My 35i is on 78,000 km so wondering whether to get the DCT done.

DCT.

That said, as a member has written elsewhere, DCT sump plate/gasket leakage & replacement seem common, so I assume the fluid is replaced then. (Mine was done under warranty and there were no details on the paperwork.)

However, under normal circumstances, I wouldn't have the DCT fluid replaced until 100,000 miles.

 

[Cees Klumper]

My DCT has 96K miles and I will probably change the fluid shortly. I am a bit concerned about the warnings ("you'll dislodge stuff and it will ruin the box") but I'll take my chances.

 

[marioz4]

My DCT has 96K miles and I will probably change the fluid shortly. I am a bit concerned about the warnings ("you'll dislodge stuff and it will ruin the box") but I'll take my chances.

yes if you dont chnage your gear fluid then "stuff" will build up inside and when you chnage fluid it has opposite effect, this is why i changed my on at 60.000milies and will keep changing it on 120k

 

[R.E92]

Make sure that you clear existing adaptations and add new ones when doing the fluid change. If you're getting it done at a BMW dealership they will do this as part of the service.

 

[Cees Klumper]

Make sure that you clear existing adaptations and add new ones when doing the fluid change. If you're getting it done at a BMW dealership they will do this as part of the service.

About adding new adaptations: any more info on that? I have the Foxwell N520 that can do a lot, but not sure about DCT adaptations. It did register a new BMW battery for me last week and there's all sorts of programming options I've seen but not come near yet, so probably it can do gearbox stuff as well.

 

[R.E92]

Make sure that you clear existing adaptations and add new ones when doing the fluid change. If you're getting it done at a BMW dealership they will do this as part of the service.

About adding new adaptations: any more info on that? I have the Foxwell N520 that can do a lot, but not sure about DCT adaptations. It did register a new BMW battery for me last week and there's all sorts of programming options I've seen but not come near yet, so probably it can do gearbox stuff as well.

I'd be surprised if it was capable. The process is quite involved. I used ISTA+ to reset mine and I had to run through 3 routines that were flagged as needing done after a DCT fluid change, mainly just re-learning the line pressure required for certain engagements. There's a few more that only need to be carried out when changing physical hardware within the gearbox.

If you search on YouTube for DCT adaptation reset there are some videos that show part of the process.

 

[Anonymous]

Make sure that you clear existing adaptations and add new ones when doing the fluid change. If you're getting it done at a BMW dealership they will do this as part of the service.

About adding new adaptations: any more info on that? I have the Foxwell N520 that can do a lot, but not sure about DCT adaptations. It did register a new BMW battery for me last week and there's all sorts of programming options I've seen but not come near yet, so probably it can do gearbox stuff as well.

I'd be surprised if it was capable. The process is quite involved. I used ISTA+ to reset mine and I had to run through 3 routines that were flagged as needing done after a DCT fluid change, mainly just re-learning the line pressure required for certain engagements. There's a few more that only need to be carried out when changing physical hardware within the gearbox.

If you search on YouTube for DCT adaptation reset there are some videos that show part of the process.

The Foxwell N520 does it very straightforward..simple..

Less obvious was how to register a new battery of differing capacity...didn’t seem to work..used Carly to do that

 

[Z4M-2006]

Doing a full adaptations on Ista is very different to doing an adaptation reset on a Foxwell..

Im suprised a Foxwell even has adaptations for a DCT....

 

[Anonymous]

Doing a full adaptations on Ista is very different to doing an adaptation reset on a Foxwell..

Im suprised a Foxwell even has adaptations for a DCT....

20i = ZF 8HP...so not DCT...apologies for the rat hole..

Whilst I’m there here’s what ZF say about oil changes

ZF automatic transmissions are filled with specially developed semi-synthetic oils.
At very high operating temperatures, the oil ages faster than under normal conditions. Examples:
 Many trips at high speeds
 Many trips while towing a trailer
 Sporty driving
Depending on the driving style, ZF recommends a transmission oil change every 80,000 to 120,000 km or after eight years at the latest

Since a DCT box has two wet clutches you would expect progressive contamination over time

 

[R.E92]

About adding new adaptations: any more info on that? I have the Foxwell N520 that can do a lot, but not sure about DCT adaptations. It did register a new BMW battery for me last week and there's all sorts of programming options I've seen but not come near yet, so probably it can do gearbox stuff as well.

I'd be surprised if it was capable. The process is quite involved. I used ISTA+ to reset mine and I had to run through 3 routines that were flagged as needing done after a DCT fluid change, mainly just re-learning the line pressure required for certain engagements. There's a few more that only need to be carried out when changing physical hardware within the gearbox.

If you search on YouTube for DCT adaptation reset there are some videos that show part of the process.

The Foxwell N520 does it very straightforward..simple..

Less obvious was how to register a new battery of differing capacity...didn’t seem to work..used Carly to do that

Would be seriously impressed if the Foxwell managed that, the DCT adaptation relearning is very different to the the normal automatic which just requires the learned values to be zeroed.

 

[Z4M-2006]

On a serious note,i would change the fluid and filter every 40k..

I have changed loads or sumps on various ZF's over the years and without exception the oil has come out heavily contaminated. I did a C63 (7G) with 41k on the other week and the oil was as black as engine oil.