Ugliest E92 M3 4.2 Build

Well I guess my power steering probably did failed on the day of the accident. I had the engine in the 1 series for about two weeks now without the power steering belt because my AC clutch got broken. Replace the AC compressor today and after I installing the belt, it turns out I have no power steering. Now it’s worse than before, hard and squeezing. What are my options for steering rack?

Jbonly21 wrote
Well I guess my power steering probably did failed on the day of the accident. I had the engine in the 1 series for about two weeks now without the power steering belt because my AC clutch got broken. Replace the AC compressor today and after I installing the belt, it turns out I have no power steering. Now it’s worse than before, hard and squeezing. What are my options for steering rack?

I suppose you have already checked the pump and ruled out a broken power steering pump? If not I'd verify the pump first before removing the steering rack. Check all of the hard lines for leeks and cracks too. Here's a rack on eBay:
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https://www.ebay.com/itm/157574356517

DrFerry thanks, I had already replaced the pump last October, and it spins freely right now, I will do some more investigation today.

Jbonly21 wrote
DrFerry thanks, I had already replaced the pump last October, and it spins freely right now, I will do some more investigation today.

Keep in mind there are two versions of the E9X M3 power steering pump. The direction of the pump changed soon after production began (about 18 months after the '07 EU launch). Since you've already replaced the pump ensure the belt is correctly routed to spin the pump in the correct direction. The pre-mid-2008 route is shown on the engine image below.
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Thanks, I am aware of that and I have been routing the belt the same as the diagram. The car has Macht Schnell underdrive kit. I might have to switch to stock.

03-21-2026

Seems like swapping in the engine was the easy part. All the little things that keeps coming up and needs to get done is driving me crazy 🤪. Turns out my power steering pump and bracket are no good. Did an alignment and my sway bar link popped out. How can I tell if my sway bar is bent?

03-22-2026

Jbonly21 wrote
Seems like swapping in the engine was the easy part. All the little things that keeps coming up and needs to get done is driving me crazy 🤪. Turns out my power steering pump and bracket are no good. Did an alignment and my sway bar link popped out. How can I tell if my sway bar is bent?

Sorry to hear the power steering pump is still giving you a hard time. It'll all be worth it in the end and you'll have a very unique 128i M3. The best way to tell if the front sway bar is bent is to carefully compare it alongside one you know is straight. Because of the curvy geometry pay close attention to the end link eye sections. Perhaps a used parts yard or even a BMW dealer parts guy might let you do a side by side comparison. You can remove the front bar and still drive it though the handling balance will shift towards oversteer. So be careful in the dry or the wet if you do decide to do that.

03-24-2026

Hey guys, couldn’t find much info on this, but just wondering if the Idrive needs the amp for it to work? My amp got damaged in the accident and now screen is red on start up and then goes back.

03-24-2026

Jbonly21 wrote
Hey guys, couldn’t find much info on this, but just wondering if the Idrive needs the amp for it to work? My amp got damaged in the accident and now screen is red on start up and then goes back.

Yes, the E92 M3 iDrive system requires the amplifier to function properly. The amplifier acts as a key component for audio, and the MOST fiber optic network loop, often linking the iDrive head unit with the amp, means removing it breaks the circuit, leading to a loss of sound and potential system malfunction.
https://www.m3post.com/forums/showthread.php?t=811628

Key Details on E92 M3 Amplifier Dependency:
Audio Failure: If the amplifier is missing or broken, you will have no sound, and sometimes the iDrive unit may fail to boot or function correctly.
MOST Bus Loop: The amplifier is part of the fiber optic ring. If removed, you must use a fiber optic termination loop/bridge (https://www.google.com/url?sa=i&source=web&rct=j&url=https://www.m3post.com/forums/showthread.php?t%3D651998&ved=2ahUKEwjpr5ynh7mTAxUzlYkEHV_WDU8Qy_kOegQIAxAD&opi=89978449&cd&psig=AOvVaw0wyfjxd2Z3gTddd4mjn5qV&ust=1774459610364000) to close the circuit to avoid losing all functions.
System Dependence: The amp converts audio, and control relies on it. While the Head Unit sends signal, the amp provides the power needed for speakers.
Coding Required: If you replace the amp with an aftermarket unit or bypass it, the car often requires coding (e.g., changing to HiFi) to operate without the stock amp.
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If you are replacing the stock amplifier, it is generally recommended to use an OEM replacement or a specifically compatible aftermarket amp with a harness to avoid these issues.
https://www.m3post.com/forums/showthread.php?t=811628

03-24-2026

DrFerry wrote
Yes, the E92 M3 iDrive system requires the amplifier to function properly. The amplifier acts as a key component for audio, and the MOST fiber optic network loop, often linking the iDrive head unit with the amp, means removing it breaks the circuit, leading to a loss of sound and potential system malfunction.
https://www.m3post.com/forums/showthread.php?t=811628

Key Details on E92 M3 Amplifier Dependency:
Audio Failure: If the amplifier is missing or broken, you will have no sound, and sometimes the iDrive unit may fail to boot or function correctly.
MOST Bus Loop: The amplifier is part of the fiber optic ring. If removed, you must use a fiber optic termination loop/bridge (https://www.google.com/url?sa=i&source=web&rct=j&url=https://www.m3post.com/forums/showthread.php?t%3D651998&ved=2ahUKEwjpr5ynh7mTAxUzlYkEHV_WDU8Qy_kOegQIAxAD&opi=89978449&cd&psig=AOvVaw0wyfjxd2Z3gTddd4mjn5qV&ust=1774459610364000 ) to close the circuit to avoid losing all functions.
System Dependence: The amp converts audio, and control relies on it. While the Head Unit sends signal, the amp provides the power needed for speakers.
Coding Required: If you replace the amp with an aftermarket unit or bypass it, the car often requires coding (e.g., changing to HiFi) to operate without the stock amp.
.

If you are replacing the stock amplifier, it is generally recommended to use an OEM replacement or a specifically compatible aftermarket amp with a harness to avoid these issues. [...]

Thanks

DrFerry really appreciate all the help!

Oe headlights, and a drive down PCH! Just crossed 800 miles on the engine.

Nice, have you given the engine the full beans yet? how is it feeling at this point, obviously in a lighter chassis its going to feel way more alive but thats awesome!

The 219Ms up front look great, and fit better than the other ones...assuming that is a front 8.5", still looks like you'll rub?

Congrats on getting everything sorted, sweet hot rod!

darren p. wrote
Nice, have you given the engine the full beans yet? how is it feeling at this point, obviously in a lighter chassis its going to feel way more alive but thats awesome!

The 219Ms up front look great, and fit better than the other ones...assuming that is a front 8.5", still looks like you'll rub?

Congrats on getting everything sorted, sweet hot rod!

Love the 219’s as well and it is a 8.5”. Been on the hunt to find another another set of 8.5” at a reasonable price for the rear, and yes they do rub a little.
Haven’t given it the full beans yet, but I have gotten on it at about 50% throttle and keeping it under 6500 rpm’s, and it feels great, a bit too loud under load.

Jbonly21 wrote
Oe headlights, and a drive down PCH! Just crossed 800 miles on the engine.

A major, major, accomplishment. Well done. Happy for you, :clap:

PS: Was the front bar bent?

DrFerry wrote
A major, major, accomplishment. Well done. Happy for you,
PS: Was the front bar bent?

Thanks, no it wasn’t, replaced sway bar link and it’s been good so far!

Finally figured out my power steering issue, it turns out I had a bad banjo bolt check valve.
Watch This Before Replacing Your BMW E9X Power Steering Pump

Jbonly21 wrote
Finally figured out my power steering issue, it turns out I had a bad banjo bolt check valve.

Great find. Years ago I heard a bad or failing banjo bolt can also cause the steering to bind up at high RPM with rapid input steering angles - such as during an Auto-X, Drifting or motorsports. The E46 M3 forums are where I recall hearing something about this - or perhaps it's a BMW 'thing'. Here's a link to a motorsports version without the check valve in case you ever needed to know. Great job hangin' in there to fix all the issues. The last 5% of any project takes as long as the first 95% - at least for most projects done right. Kudos to you. PS: Could the failed valve possibly have caused your original canyon run accident?
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https://www.moreheadspeedworks.com/product/e46-e9x-e8x-m14-steering-banjo-bolt-w-o-check-valve
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From the Product Page:
"The smaller M14 banjo bolt found in the steering rack of E46 and later BMWs contains a small plastic ball check valve. This valve will jam shut if you have a jolt to the steering system (hard curbing, wreck, wheel to wheel contact, etc), which in turn will stop flow through the pump and will destroy it in short order.

We’ve also seen where high power steering fluid temps can soften and deform the plastic ball, also causing it to become a blockage.

This banjo bolt is a direct replacement for BMW PN: 32416781261 or 32410141423

Includes 2 aluminum crush washers.

Applications: Most E46 and later models that have hydraulic steering."
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https://www.tiktok.com/@driftacrosstheworld/video/7424089752367844641
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DrFerry wrote
Great find. Years ago I heard a bad or failing banjo bolt can also cause the steering to bind up at high RPM with rapid input steering angles - such as during an Auto-X, Drifting or motorsports. The E46 M3 forums are where I recall hearing something about this - or perhaps it's a BMW 'thing'. Here's a link to a motorsports version without the check valve in case you ever needed to know. Great job hangin' in there to fix all the issues. The last 5% of any project takes as long as the first 95% - at least for most projects done right. Kudos to you. PS: Could the failed valve possibly have caused your original canyon run accident?
.
https://www.moreheadspeedworks.com/product/e46-e9x-e8x-m14-steering-banjo-bolt-w-o-check-valve
.
From the Product Page:
"The smaller M14 banjo bolt found in the steering rack of E46 and later BMWs contains a small plastic ball check valve. This valve will jam shut if you have a jolt to the steering system (hard curbing, wreck, wheel to wheel contact, etc), which in turn will stop flow through the pump and will destroy it in short order.

We’ve also seen where high power steering fluid temps can soften and deform the plastic ball, also causing it to become a blockage.

This banjo bolt is a direct replacement for BMW PN: 32416781261 or 32410141423

Includes 2 aluminum crush washers.

Applications: Most E46 and later models that have hydraulic steering."
.
https://www.tiktok.com/@driftacrosstheworld/video/7424089752367844641
.

Never heard of it before, but it does make sense. Before the accident, it did seem like it was binding. I am just glad it’s one less thing I have to worry about.