The steering system on your BMW E46 uses a hydraulic steering rack that relies on hydraulic pressure to assist with turning the wheels. This fluid, aptly called power steering fluid, also helps lubricate the multiple moving parts in the steering system. Over time, it can pick up debris and metal shavings that will alter its viscosity, affecting steering performance.
These pollutants can also cause parts of the steering system — like seals, gaskets, and the power steering pump — to wear out prematurely. The only way to avoid this is to have the fluid replaced preemptively — and this is called a power steering flush.
In this article, we’ll take you through everything you need to know about a BMW E46 steering flush, with a step-by-step guide on how to do one on your own.
When and Why Should You Flush Your Power Steering?
Like most fluids in your car, the power steering fluid can get contaminated over time. Apart from affecting the way the fluid works, the contaminants can also cause damage to seals, O-rings, and other parts of the steering system. Unfortunately, a recommended interval for a power steering flush is not something you may always find in your E46 owner’s manual, and it’s something you’ll have to assess the need for on your own.
The most obvious giveaway that it may be time for a power steering flush is problems with how your steering wheel feels. If it demands more effort than usual, it may be time to have the old fluid drained and replaced. This happens when the fluid can no longer deliver the same levels of hydraulic pressure. You might also notice your steering wheel makes an unusual noise every time you turn it since the system’s moving parts aren’t adequately lubricated.
You’ll experience similar symptoms when there’s a power steering fluid leak, so it’s also a good idea to check for that.
While it may not seem necessary, it’s advisable to carry out a power steering flush even before you start noticing these symptoms, so you can avoid damaging any components in the steering system. The ideal intervals for this can vary depending on what kind of fluid you’re using, the conditions you drive in, and more. That said, every 60,000 to 80,000 miles is a good point of reference.
Changing your E46 power steering fluid at regular intervals will ensure you have smooth steering that performs as it should and keep your power steering pump healthy and problem-free.
How to Choose the Right Power Steering Fluid for Your E46
There are multiple types of power steering fluids out there, and the best specification for your car is typically the one recommended by the manufacturer. You can find this information in the owner’s manual or the power steering fluid reservoir cap. In the case of the BMW E46 3-Series, the company uses ATF or Automatic Transmission Fluid for the power steering system. Of the several ATF options out there, the BMW-recommended fluid is Dexron III.
Genuine (Dexron) vs. Aftermarket
While the manufacturer recommends using Dexron, technically, you should be able to use any ATF for the power steering without facing any trouble. Dexron is available in different specifications — Dexron, Dexron-III, Dexron-VI, etc. — and BMW typically used Dexron-III in its cars. Keep in mind that this Dexron standard is now obsolete. You can use Dexron-VI as it is backward compatible.
This has created some confusion as to what is a suitable replacement. In reality, any modern ATF will do the job just fine. Check out our selection of ATF for your E46 power steering system.
Apart from ATF, some power steering systems from other manufacturers use dedicated power steering fluid. While you can use this in your car, it may cause problems for your power steering pump or the rack and pinion, so we strongly advise against doing so. As such, it’s best to stick to ATF, if not Dexron-III/VI.
How To Do a Power Steering Flush on a BMW E46
There are two ways to perform a power steering flush on your BMW E46. The first colloquially referred to as the ‘Turkey Baster Method,’ is more straightforward and quicker but doesn’t always get the perfect result.
The second option is a more comprehensive flush. It is the recommended course of action if you want a complete flush or are going to replace the power steering fluid with a different specification. However, this will require a jack stand and can be slightly more complex and time-consuming.
If you’re looking for a quick flux, the Turkey Baster Method will do. Here’s how it works.
Remove the Engine Cover
Remove the engine cover by unplugging the plastic pins that fix it onto the engine bay. This will give you easier access to the power steering fluid reservoir.
Extract Old Power Steering Fluid
Open the power steering reservoir cap and use a turkey baster, a manual fluid extractor, or a pump to suck out the existing power steering fluid. Fresh fluid is transparent with a dark wine-red color, and it will progressively turn black and opaque as it ages. If the fluid is dark, and you can’t see the bottom of the reservoir, it’s a good sign that you’re carrying out a power steering flush at the right time.
Fill Fresh Power Steering Fluid
Once you’ve removed as much fluid as possible, you can fill the reservoir with the fresh ATF of your choice. The reservoir cap has a dipstick to show you the fluid level in the reservoir, and you can use it to check whether you’ve reached the recommended level.
Circulate the Fluid in the Power Steering System
Once you’ve filled the reservoir with fresh fluid, close the cap, turn the engine on, and turn the steering wheel from lock to lock. This will force the power steering fluid to circulate in the system.
Repeat
When you now open the power steering fluid reservoir, you will probably see that the oil is old and dark again. Don’t worry; this is just the existing oil from the power steering lines that could not be sucked out earlier.
You can do so now and dispose of the liquid carefully. Then, add more fresh fluid, and repeat the above steps until you no longer see dirty fluid when you open the reservoir cap.
Get the Right Power Steering Fluid for Your Bimmer!
Performing a power steering flush may not be something you have to do often, but it’s crucial to ensure your E46 performs as it should. And, since it requires no special skills or tools, you can save money by doing it yourself.
If you want to purchase Genuine BMW power steering fluid or options from reputed aftermarket names like Pentosin and ZF, you can order them right away from Bimmers.com. We also stock everything else you might need if you’re working on your BMW, from power steering racks, reservoirs, and hose kits, to suspension and engine components.
Just head to the website and enter your car’s year and model — we’ll only show you parts that are a perfect fit.
