Electric power steering

[gpchamp]

What year did electric power steering become standard for the 1-series and the 3-series?

[ScotchAndCigar]

It was introduced on the Z4 for the '03 model, and then appeared on subsequent new models, such as the 3-series in '05, and the 1-series in '08 (or whenever it was introduced).

[Tom K.]

Originally Posted by ScotchAndCigar

It was introduced on the Z4 for the '03 model, and then appeared on subsequent new models, such as the 3-series in '05, and the 1-series in '08 (or whenever it was introduced).

Source?

While the Z4 did have electricly boosted steering (with a rather numb steering feel), both 1 and 3 series continue to have power steering pump & hose part numbers listed - indicating good old hydraulic boost.

http://www.trademotion.com/partlocat...layCatalogid=0

Tom

[ScotchAndCigar]

My source is that I owned an '06 Z4, which had incredible steering - light, responsive, with excellent feedback - not at all numb.

Here's an excerpt from BMW.com
A turn for the better.
Every movement requires energy, this is why Electric Power Steering only acts when it is needed. To give you more bends per litre, an electric motor is used to assist the steering. However, unlike conventional hydraulic systems, Electric Power Steering is supported by an electric motor which helps to ensure that energy is only used during actual steering manoeuvres. If the steering wheel is kept in a constant position when driving straight ahead or cornering, the electric motor is inactive and therefore does not use any energy.

BMW models with this technology
BMW 1 Series (three-door)
BMW 1 Series (five-door)
BMW 1 Series Coupé
BMW 1 Series Convertible
BMW 3 Series Sedan
BMW 3 Series Touring
BMW 3 Series Coupé
BMW 3 Series Convertible
BMW Z4 Roadster

[gpchamp]

I have a 2008 335i and a 2009 135i. Do they have electric power steering or hydraulic?

[Tom K.]

Originally Posted by maxnix

You know, I have my doubts also as the electric motor is not listed in the parts description, and the hydraulic power steering has a cooler, so it is responsible for all of the work.

And when you check out the power steering pump & hoses for the electricly boosted Z4, you get "No items found in this category"

http://www.trademotion.com/partlocat...layCatalogid=0

gpchamp: You have hydraulic power steering in both your BMWs.

Tom

[Tom K.]

Originally Posted by ScotchAndCigar

My source is that I owned an '06 Z4, which had incredible steering - light, responsive, with excellent feedback - not at all numb.

Here's an excerpt from BMW.com
A turn for the better.
Every movement requires energy, this is why Electric Power Steering only acts when it is needed. To give you more bends per litre, an electric motor is used to assist the steering. However, unlike conventional hydraulic systems, Electric Power Steering is supported by an electric motor which helps to ensure that energy is only used during actual steering manoeuvres. If the steering wheel is kept in a constant position when driving straight ahead or cornering, the electric motor is inactive and therefore does not use any energy.

BMW models with this technology
BMW 1 Series (three-door)
BMW 1 Series (five-door)
BMW 1 Series Coupé
BMW 1 Series Convertible
BMW 3 Series Sedan
BMW 3 Series Touring
BMW 3 Series Coupé
BMW 3 Series Convertible
BMW Z4 Roadster

We all know that the first generation Z4 had electricly boosted steering - I'm glad you liked yours, but I didn't care for the steering feel in mine. But in the US, it and the X3 appear to be the only models so equipped. As BMW.com is an international site and your list includes models not available in North America, maybe it is available on those models in Europe, but not in the US.

Can you provide the link?

Tom

[Bimmer-Bob]

As usual, RealOEM is very helpful in this situation.

For the 128i, it lists only "Hydraulic Steering." For the Z4, only "Steering, Electric." For the 125i (Europe) it lists both - the electric steering only on vehicles with something called the "CO2 Package."

EDIT: As an aside, if anyone cares, it appears the steering rack is sourced from ZF.

[ScotchAndCigar]

Apparently this issue has come up before.
http://www.bmwcca.org/forum/showthread.php?t=390

It seems to be saying that euro 1-series models (only) have EPS, which doesn't make a lot of sense to me, since our cars are built in Germany either way. This also doesn't address the 3-series question.

I didn't expect there to be a crazy apportionment of electric/ hydraulic designs, within one car model.

[doublevanosrc]

I thought the current 3 series still had the hydraulic rack??

[doublevanosrc]

I remember reading in the BMW brochure that its electric on both 128i/135i.

[gpchamp]

Originally Posted by Tom K.

And when you check out the power steering pump & hoses for the electricly boosted Z4, you get "No items found in this category"

http://www.trademotion.com/partlocat...layCatalogid=0

gpchamp: You have hydraulic power steering in both your BMWs.

Tom

Thank you!

[ScotchAndCigar]

There's much data supporting electric in the 128, and hydraulic in the 135
http://www.automobilemag.com/reviews...ble/index.html
Excerpt:
Our 125i also differed from U.S.-bound cars by being equipped with regenerative braking and a deep-cycle battery (which lessen the draw from the alternator) along with closing flaps behind the grille (to aid high-speed aerodynamics when less engine cooling is needed), all elements of BMW's Efficient Dynamics effort to lower fuel consumption. The car also featured electric power steering (as will our 128i), but as much as we're in favor of efficiency, that's one item we'd rather skip. This is one of the better electric-assist systems; it's precise and even provides a measure of steering feel, but it doesn't have the natural build-up of effort that helps make BMW's hydraulic-assist steering so superb. Happily, that system is standard on the 135i - and just as happily, BMW's weirdly nonlinear active steering is relegated to the options list.

Even with electric power steering, the 1-series convertible is easily the best drive in its segment.

[Bimmer-Bob]

^ I don't know, I think RealOEM trumps a pre-production press review.

[Tom K.]

Originally Posted by Bimmer-Bob

^ I don't know, I think RealOEM trumps a pre-production press review.

And my '08 128i has a power steering pump - and a superior feel to my former Z4 with electric steering.

ScotchandCigar: Look under your hood. Do you see the PS Reservoir near the firewall (part #5 in the drawing)?

http://www.trademotion.com/partlocat...make=3&model=1 Series Convertible&year=2011&graphicID=1980310&callout=5& catalogid=2&displayCatalogid=0

(Copy & paste the entire URL)
Tom

[ScotchAndCigar]

Originally Posted by Tom K.

ScotchandCigar: Look under your hood. Do you see the PS Reservoir near the firewall (part #5 in the drawing)?

Haven't looked yet, but by now I would guess I have one. Seeing that the 1's, 3's and Z4's all have available the same engine & trans, plus the Z4 had electric steering in '03, plus about 100 different resources (not just Automobile mag) all say that the 1's have electric steering, I assumed that to be the case. In the 3 weeks I've owned the car, I never thought to check for a PS res.

I know I have an electronic throttle, electric water pump, and no dipstick, right?

[ScotchAndCigar]

BTW, I think one's impressions of steering feel is somewhat relative. I had both an e36 3-series and a Z3 with traditionally heavy, low-assist steering. I also owned an early e46 3-series with overly light steering. So my Z4 felt like the perfect compromise to me at the time. The 1er is definitely weightier.

[Tom K.]

Originally Posted by ScotchAndCigar

Haven't looked yet, but by now I would guess I have one. Seeing that the 1's, 3's and Z4's all have available the same engine & trans, plus the Z4 had electric steering in '03, plus about 100 different resources (not just Automobile mag) all say that the 1's have electric steering, I assumed that to be the case. In the 3 weeks I've owned the car, I never thought to check for a PS res.

I know I have an electronic throttle, electric water pump, and no dipstick, right?

IIRC, Automobile & the other sources you mention were repeating information put out by BMW prior to the introduction of the US 1 series in late '07/early '08. There was some grumbling at the time from those of us who had experienced Electric steering on the Z4 and (for whatever the reason) BMW subsequently decided to go with conventional hydraulicly boosted steering on the 1 series in the US.

While I don't know about the throttle & water pump, you are correct that there is no point in looking for a dipstick. Instead, after the car has warmed up, scroll through the OBC items with the lever (not the end button) on the turn signal lever with the motor running. Push the end button to select Oil Level after scrolling to it.

Since the 128i is graced with neither a water nor oil temp gauge, some of us use this oil level indicator to indicate when the motor has warmed up sufficiently for more "spirited" driving. Prior to that, there will be no oil level reading, just an icon of a spinning clock.

Tom

[Tom K.]

Originally Posted by ScotchAndCigar

BTW, I think one's impressions of steering feel is somewhat relative. I had both an e36 3-series and a Z3 with traditionally heavy, low-assist steering. I also owned an early e46 3-series with overly light steering. So my Z4 felt like the perfect compromise to me at the time. The 1er is definitely weightier.

I had the first year E46 ('99 328i) with the heavier steering and liked it - the 1er's steering is slightly stiffer, but I'm glad BMW has attempted to "correct" it as they did with the 2000 (01?) E46.

The Z4 was a great handling car (although my wife turned somewhat green when we followed some rather exuberant Mini drivers down the Tail of the Dragon in the Smokies), but I could never get used to the steering feel. For me, one of the biggest differences between the Z4 and 128i is the much more compliant ride in the larger 1er. Plus my aging, arthritic neck and back manage to get in and out of the 128i 'vert much more easily.

Tom

[ScotchAndCigar]

Originally Posted by Tom K.

For me, one of the biggest differences between the Z4 and 128i is the much more compliant ride in the larger 1er. Plus my aging, arthritic neck and back manage to get in and out of the 128i 'vert much more easily.

Wow, I thought I was the only aging Z4 owner trading to the 128 vert for the ride and ingress/egress! Yes, compared to the short-wheelbase Z4, the 1er is like a limo, especially over those New England frost-heaves.

I owned an '01 e46 325ci, and the light steering was corrected for '02.

[aerobod]

A list of the 1 & 3-series that use an electric steering rack:

Part 32106793458 (AT-steering box, electr.) was found on the following vehicles:

E81: Details on E81
E81 116d 3 doors, Europe
E81 116i 1.6 3 doors, Europe
E81 116i 2.0 3 doors, Europe
E81 118d 3 doors, Europe
E81 118i 3 doors, Europe
E81 120d 3 doors, Europe
E81 120i 3 doors, Europe
E81 123d 3 doors, Europe
E81 130i 3 doors, Europe

E82: Details on E82
E82 118d Coupe, Europe
E82 120d Coupe, Europe
E82 120i Coupe, Europe
E82 123d Coupe, Europe
E82 125i Coupe, Europe

E87N: Details on E87N
E87N 116d 5 doors, Europe
E87N 116i 1.6 5 doors, Europe
E87N 116i 2.0 5 doors, Europe
E87N 118d 5 doors, Europe
E87N 118i 5 doors, Europe
E87N 120d 5 doors, Europe
E87N 120i 5 doors, Europe
E87N 123d 5 doors, Europe
E87N 130i 5 doors, Europe

E88: Details on E88
E88 118d Convertible, Europe
E88 118i Convertible, Europe
E88 120d Convertible, Europe
E88 120i Convertible, Europe
E88 123d Convertible, Europe
E88 125i Convertible, Europe

E90: Details on E90
E90 316i Sedan, Europe
E90 318d Sedan, Europe
E90 318i Sedan, Europe
E90 320d Sedan, Europe
E90 320i Sedan, Europe
E90 325d Sedan, Europe
E90 325i Sedan, Europe
E90 330d Sedan, Europe
E90 330i Sedan, Europe

E90N: Details on E90N
E90N 316d Sedan, Europe
E90N 316i Sedan, Europe
E90N 318d Sedan, Europe
E90N 318i Sedan, Europe
E90N 320d Sedan, Europe
E90N 320d ed Sedan, Europe
E90N 320i Sedan, Europe
E90N 323i Sedan, Europe
E90N 325d Sedan, Europe
E90N 325i Sedan, Europe
E90N 330d Sedan, Europe
E90N 330i Sedan, Europe

E91: Details on E91
E91 318d Touring, Europe
E91 318i Touring, Europe
E91 320d Touring, Europe
E91 320i Touring, Europe
E91 325d Touring, Europe
E91 325i Touring, Europe
E91 330d Touring, Europe
E91 330i Touring, Europe

E91N: Details on E91N
E91N 316d Touring, Europe
E91N 318d Touring, Europe
E91N 318i Touring, Europe
E91N 320d Touring, Europe
E91N 320i Touring, Europe
E91N 323i Touring, Europe
E91N 325d Touring, Europe
E91N 325i Touring, Europe
E91N 330d Touring, Europe
E91N 330i Touring, Europe

E92: Details on E92
E92 316i Coupe, Europe
E92 320d Coupe, Europe
E92 320i Coupe, Europe
E92 325d Coupe, Europe
E92 325i Coupe, Europe
E92 330d Coupe, Europe
E92 330i Coupe, Europe

E92N: Details on E92N
E92N 316i Coupe, Europe
E92N 320d Coupe, Europe
E92N 320i Coupe, Europe
E92N 323i Coupe, Europe
E92N 325d Coupe, Europe
E92N 325i Coupe, Europe
E92N 330d Coupe, Europe
E92N 330i Coupe, Europe

E93: Details on E93
E93 320d Convertible, Europe
E93 320i Convertible, Europe
E93 325d Convertible, Europe
E93 325i Convertible, Europe
E93 330d Convertible, Europe
E93 330i Convertible, Europe

E93N: Details on E93N
E93N 320d Convertible, Europe
E93N 320i Convertible, Europe
E93N 323i Convertible, Europe
E93N 325d Convertible, Europe
E93N 325i Convertible, Europe
E93N 330d Convertible, Europe
E93N 330i Convertible, Europe

[Tom K.]

Originally Posted by ScotchAndCigar

Wow, I thought I was the only aging Z4 owner trading to the 128 vert for the ride and ingress/egress! Yes, compared to the short-wheelbase Z4, the 1er is like a limo, especially over those New England frost-heaves.

I owned an '01 e46 325ci, and the light steering was corrected for '02.

But the Z4 was delightful on a warm summer's day exploring Rt. 100 in VT., Rangeley Lake in Maine, Mt. Washington in NH, etc., etc.

Of course, you'll quickly discover that the 128i 'vert is no slouch on these roads, either - plus there's more room if you are into antique shopping!

Tom