prevention/repair of common issues Z4 35i

[keving1]

Thanks - i did not know it work all the time, well too late now car in garage all 4 new normal suspension in...i hope i will not regret it!

I am also changing dif and trans oil, i been told its a must!

I wouldn't say either are a must, never heard of diff oil being replaced. The DCT transmission has a common fault where the sump leaks so that's something that needs doing at the same time as a trans flush.

Had long chat and did research, YES dif oil needs regular changing, this life time b*** s**** from bmw is basically life of dif some 100k+ but if you chnage oil on 50k or even 30k dif will last 10x time than original BMW "lifetime". Same for transition oil, regular chnage is needed. Problem occur when you change oil first time on high mileage then new oil dos more damage than if you just leave it as it is.

So two options, changing each 30-50k to have long life or not changing at all and as such your gear box will blow on 100k+ and u will need a new one or ne wcar something that BMW wants to happen. My gear chnage is much better now with new oil. my is manual

Where are you getting your information from

You are stating if you change your gearbox oil every 50k or 30k it will last 10x longer - 1 million miles plus

And if you change it first time at high mileage and then use new oil does more damage - WHY???

[marioz4]

I wouldn't say either are a must, never heard of diff oil being replaced. The DCT transmission has a common fault where the sump leaks so that's something that needs doing at the same time as a trans flush.

Had long chat and did research, YES dif oil needs regular changing, this life time b*** s**** from bmw is basically life of dif some 100k+ but if you chnage oil on 50k or even 30k dif will last 10x time than original BMW "lifetime". Same for transition oil, regular chnage is needed. Problem occur when you change oil first time on high mileage then new oil dos more damage than if you just leave it as it is.

So two options, changing each 30-50k to have long life or not changing at all and as such your gear box will blow on 100k+ and u will need a new one or ne wcar something that BMW wants to happen. My gear chnage is much better now with new oil. my is manual

Where are you getting your information from

You are stating if you change your gearbox oil every 50k or 30k it will last 10x longer - 1 million miles plus

And if you change it first time at high mileage and then use new oil does more damage - WHY???

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

[Frankie169]

Will be following this post with interest as I have a 10 year old 35i, 32k on the clock and also been thinking about preventive maintenance and prioritising on what to do

[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?

[marioz4]

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

[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'.

[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'.

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'.

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.

[Pbondar]

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