Power Steering Fluid

[Grayson]

Great DIY write up in the pinned post! I just have found a ton of conflicting information on what fluid to use for the e46 m3. Turners / ECS kits have CHF power steering fluid or redline power steering fluid but some forums say DO NOT USE CHF. ATF Dex 3 or better seems to be the other popular opinion. If someone smarter than me could shed some light, much appreciated.

[Nuclear Rabbit]

The factory oil for the M3 was a DEXRON-III ATF, however this specification was discontinued in 2011. DEXRON-VI is backwards compatible and I've been using it in my car with good results. You will need one quart.

[mrgizmo04]

If you replace the reservoir as part of the refresh or you simply want to replace the filter (which you cant because it's built into the reservoir), the new OE BMW reservoir cap is stamped to use CHF. I've been running CHF for about 20k miles.

I know this doesn't help .

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[bigjae46]

There is no filter, the white disc is a baffle.


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[Feffman]

Trusty old Mobil-1 ATF has worked like a charm. A friend suggested I zip tie a "diaper" (oil soaking material from a parts store) around the top of the power steering reservoir. This too works well.

Feff

[Grayson]

Thank you gentlemen. Seems like ATF 4 for a fluid top off and when I replace reservoir / flush the whole system CHF if fine to run.

Do we have a consensus? haha

[bigjae46]

Yes. I use the Castrol multi ATF/Dexron or redline D4ATF.


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[JamesSJ1]

Figured I'd throw my 2-cents in here too. Just refreshed mine while doing a rod bearing job. Used Valvoline Maxlife ATF, as it's a full-synthetic DEX3/4 compatible ATF. Castrol multi ATF and Redline D4ATF that bidjae46 are also very good choices. Really, just about any Dex3 compatible ATF is fine in there.

[r4dr]

The PS cap says CHF because BMW has one part numbers for all cars. Factory fill through E46 was ATF, E90 started using CHF. I believe there’s a sticker that goes on top of the cap that says ATF.

[timmo]

Trusty old Mobil-1 ATF has worked like a charm. A friend suggested I zip tie a "diaper" (oil soaking material from a parts store) around the top of the power steering reservoir. This too works well.

Feff

You could also make a catch can that attaches to the vent of the reservoir cap, like so

[bigjae46]

The PS cap says CHF because BMW has one part numbers for all cars. Factory fill through E46 was ATF, E90 started using CHF. I believe there’s a sticker that goes on top of the cap that says ATF.

There is CHF11 and CHF11S. They are not interchangeable. E9X used CHF11S.


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[TexaZ3]

You could also make a catch can that attaches to the vent of the reservoir cap, like so

Or just replace the cap/o-ring.

[timmo]

Or just replace the cap/o-ring.

That's not the problem. My o-ring is new, at the track the fluid comes out of the vent hole in the cap.

[kokgo20]

That's not the problem. My o-ring is new, at the track the fluid comes out of the vent hole in the cap.

I usually wrap a paper shop towel around the cap and zip tie it, it keeps everything clean.

[TexaZ3]

That's not the problem. My o-ring is new, at the track the fluid comes out of the vent hole in the cap.

Your fluid is just too hot then.