BMW 3 Series E46 - BMW Auto Trans Fluid Change or Not to Change

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Fri 6 May 2016 13:49
BMW 3 Series E46 - BMW Auto Trans Fluid Change or Not to Change - pbirl

I have a 2003, 320i (2.2) with the ZF 5 speed auto. It has only covered 29,000 miles (mostly long runs) - full BMW history. A bit of a time warp car.

Most Indepedent specialists recommend changing out the transmission fluid (and the differential) - due to the age. Some have told me at that mileage that it's fine. BMW dealers are all (with exception of one) with the sealed for life mantra. Transmission is operating perfectly - no bumps or noises or hesitation. If it's necessary I'd like to get it done, if not I'd prefer to save myself a few hundred quid! Any sound advice would be greatly appreciated.

One other thing - water pump - replace as a preventative measure or leave well enough alone - no coolant loss or noises.

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Fri 6 May 2016 14:22
BMW 3 Series E46 - BMW Auto Trans Fluid Change or Not to Change - RobJP

At only 29k miles, it's barely run in. And that 2.2 straight 6 is one of the finest engines ever made (in my opinion). The noise it makes is just sublime (we used to have a Z3 with the 2.2, lovely car, especially with the roof down)

I'd probably not bother getting it done, simply because the fluid in there has had such little use it's probably not worn out, or started to burn up.

Those gearboxes, whilst they do have a bit of a reputation for going wrong, usually do so after 80-100k miles.

On the other hand, with that low mileage, it's going to start to appreciate in another 5 years or so, as so few of them will be left. In which case, spending that money on it now will only help it in the long run.

All depends on you really. If the money is sitting there surplus, then get it done. But if not, then I certainly wouldn't be stressing over it.

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Fri 6 May 2016 14:55
BMW 3 Series E46 - BMW Auto Trans Fluid Change or Not to Change - pbirl

Yes, it's a lovely engine, but not a quick as one would expect for a 2.2 - unless you gun it! I think the exhaust note from this engine in a Z model or the 3 series coupe has more of a growl than in the saloon - alas!

My Indy in Dublin (Baldoyle Autos) has quoted €500 to do the transmission fluid and filter and the differential fluid - so I think I'm going to get it done. The fluid is very pricey. BMW dealer quoted me €485 to do the tranmission and €185 to do the differential (not too bad). I also see BMW in Ireland will do an oil and filter service while you wait for €166 - which is very reasonable.

My view is that any fluid will deteriorate with time, irrespective of usage. Also, Andy Miller at Old Colonel Cars, was emphatic about getting all of the fluids replaced.

Edited by pbirl on 06/05/2016 at 14:57

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Fri 6 May 2016 16:58
BMW 3 Series E46 - BMW Auto Trans Fluid Change or Not to Change - Brit_in_Germany

ZF's guidance is change at 50-75,000 miles (depending on how hard the box is stressed) or at least every 8 years.

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Fri 6 May 2016 17:16
BMW 3 Series E46 - BMW Auto Trans Fluid Change or Not to Change - slkfanboy

It would be worth check the level as a small leak or just time could leave it low.

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Fri 6 May 2016 18:59
BMW 3 Series E46 - BMW Auto Trans Fluid Change or Not to Change - pbirl
I had read that ZF were recommending 100,000 km changes but could not find a time period limit. In any event, at 13 years, I'm going to have it and the filter changed. There is no leakage.
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Fri 6 May 2016 19:05
BMW 3 Series E46 - BMW Auto Trans Fluid Change or Not to Change - pbirl
And ZF are very clearly at odds with BMW! I would think that fluid costing over €20 per litre must have a high degree of robustness and longevity. I also assume there are many BMW automatics at over 100,000 miles running fine on the original fluid. I guess non changing of fluid may not be the primary reason auto boxes give trouble. There are people who'd break even the most robust object!
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