Like any other BMW car, while driving a BMW E46, you might expect a super efficient power steering system that provides outstanding steering feedback without serious exertion.
But do you know the BMW power steering fluid E46 is the life-juice of the steering system? Power, precision, responsiveness, and control, every technical feedback you desire from your BMW E46 is related to the power steering fluid.
In this article, our goal is to give you every bit of details about the BMW E46 power steering fluid. Keep reading to find out more!
How Does The Power Steering System Work In The BMW E46?
Knowing how your BMW E46’s power steering system works will give you a basic idea about the role of power steering fluid. So, how does it work?
The steering mechanism used in the BMW E46 is called rack-and-pinion steering. With the inclusion of an optional active power steering assist system, it’s named power-assisted rack-and-pinion steering. Here is how the whole system works:
Sliding Toothed Racks
Technically, as you turn the steering wheel to the right, a small rack of tiny pinion gears rotates and then a toothed rack slides accordingly. This rack is connected to tie rods that steer the front wheels.
At the same time, the engine accessory belt powers the hydraulic pump, which forces fluid into the steering hoses, resulting in piston motion within the steering rack.
Fluid Pressure Control and Force Multiplication
The guiding hydraulic pressure valve of the steering rack controls hydraulic fluid levels in the two cylinders depending on the rotational speed and force applied to the pinion gear.
So, when you turn the steering wheel, the amount of pressure in the hydraulic lines increases, which empowers you to steer the wheels.
Steering Adjustment Via Assist System
The optional active steering system in your BMW E46 multiplies the hydraulic pressure or the steering force in the lines based on your vehicle’s speed.
When you drive at a low speed or going to park your vehicle, the power steering assist system maximizes convenience by automatically adjusting the steering speed and power supplied to the wheels. The driving assist is significantly decreased at high speeds.
However, the microprocessor used in the steering assist system reduces rollover risk by defusing the steering system and reducing unintended rapid steering when the vehicle speed reaches around 75 mph (120 kph) or above.
Types Of Power Steering Fluid For The BMW E46
Luxury European vehicles, like BMWs, dictate high standards in performance. So, you should have vigilance when choosing a power steering fluid and pick one which is designed for your specific model and trim.
You’ll find many sorts of power steering fluid, and the best choice for your car is typically the one that your manufacturer recommends.
Generally, the power steering fluid reservoir cap of your BMW E46 will indicate which fluid you should use. It will either have an ATF mark or a label showing CHF.
BMW has used ATF as the primary power steering fluid in their vehicles for over a decade and any conventional brand or type is acceptable.
However, for your E46, BMW recommends
- Dexron III
ATF is extremely common at auto stores for an affordable steering fluid replacement. Whilst CHF-11S fluid is on the expensive side.
Tips on Choosing Power Steering Fluid for BMW E46
Even though BMW advises using Dexron III ATF, practically, you are free to use any ATF for power steering without any trouble. You may find Dexron ATF with diverse specifications marketed as Dexron II, Dexron IID, Dexron III, etc.
According to some experts, you can use Dexron IID or even the Dexron IV if you desire, particularly in the 1999-2005 BMW E46 Saloon. Whilst, some particular BMW E46 models come with CHF-11S marked on the cap, so there you have no choice.
In the case of ATF fluids, most of them will meet or exceed the requirements of your E46 power steering system. But, the game will be changed completely if you have a power steering system from other manufacturers.
In such cases, those power steering systems incorporate only the dedicated power steering fluid made by the manufacturer.
Nonetheless, we recommended using at least ATF (if you don’t find Dexron III or IID) over anything else. This is because a power steering fluid mixed with the wrong fluid can potentially damage the rack and pinion or power steering pump.
Read Also: BMW Power Steering Fluid E90 (BMW 3-Series)
How to Check the Power Steering Fluid Level in the BMW E46?
Checking the level of power steering fluid in your BMW E46 is a straightforward process. The first step is to pry off the hood shroud covering the engine of your car.
Brackets for power steering fluid are usually positioned on and then locate the bracket on the left frame of the car just behind the wheels. They are clearly labeled with the words “steering fluid.”
The fluid reservoir cap should be clearly labeled, and it generally has some special markings that indicate whether you need to add fluid and even then how much. This is how you can check the power steering fluid level in your BMW e46.
Importance of Choosing the Right Power Steering Fluid For BMW E46
Choosing the right power steering fluid for your BMW E46 is extremely important. We have already discussed what type of power steering fluid you should use in your BMW E46.
Yeah, we have mentioned that you can pick any ATF apart from the recommended Dexron III. However, the main concern arises when you opt for other fluid types such as Synthetic High-Performance Hydraulic (Central) Fluids (CHF) internationally or by mistake.
Here are some negative consequences of using the wrong steering fluid that visualize the importance of choosing the right steering fluid:
Premature Wear and Damaged Steering Pump
Different power steering fluids have different thicknesses. Aside from transmitting steering force, the steering fluid plays an indispensable role, which is lubricating internal parts.
So, if you choose the thinner fluid like CHF, your power steering won’t get the proper lubrication it would get with ATF. As a result, your power steering components will be damaged by premature wear. Whilst, using a thicker fluid will damage the steering pump.
Swelling Hoses or Leaks Development
These consequences are also related to the power steering fluid’s lubricity and suitability. When your car’s power steering components are not appropriately lubricated due to using incorrect fluid, you may notice several issues.
For instance, the seals might swell, bearings might be ruined because of insufficient friction, and hose tubes might have leakage, as certain fluids can break down hoses. This probably won’t occur immediately, but it will eventually happen over a period of time.
Signs That It’s Time to Change the Power Steering Fluid in the BMW E46
As you may imagine, system additives, such as power steering fluid, will not possess a lengthy lifespan. Over time, the fluid will be weakened and will develop into debris.
This could pose a problem for the pump and other components of the steering system. Replacing the fluid and having the system flushed will stop it from having any issues and affecting the automobile’s functionality.
Unfortunately, you are not always going to find a specific time frame for changing the power steering fluid detailed in your E46 owner’s manual. That means it’s something you’ll have to personally come across.
With this in mind, we have detailed some of the common signs that urge power steering fluid replacement below.
The simplest way to tell if it’s time for a power steering fluid change is if your steering wheel requires extra effort than usual. In such cases, your fluid is longer able to maintain optimal pressure levels due to the degradation. As a result, you’ll find it hard to steer or take turns.
One of the most obvious symptoms of bad or low power steering fluid is hearing an unusual sound when turning your power steering. It’ll be like a groaning noise.
A lot of times when the fluid level is low, you’ll actually get air pockets or air bubbles in your ATF fluid, and that can cause the power steering pump to fail to maintain proper pressure. This will eventually create strange noises.
Yes, such noise can stem from other mechanical parts. So, it’s better to get it checked by your trusted mechanic. If it’s due to low fluid, you have to flush the system and pour the reservoir with fresh fluid.
When you’re checking your E46’s power steering system and its fluid level, it’s good to check the color of the fluid once. By doing this you can easily determine whether a power steering fluid replacement is necessary.
Generally, the ATF used in BMW E46 vehicles is transparent red. However, if it’s contaminated or deteriorated heavily, the fluid will turn into a dark color. So, in case you see the fluid is too dark, you should install fresh fluid.
How to Change the Power Steering Fluid in the BMW E46
Many people often remain confused about power steering fluid flush and change. Actually, flushing the fluid means you’re evacuating the whole power steering system using a flush machine.
Whilst, regular fluid change is just draining the old fluid and topping off the reservoir with fresh one. However, when it comes to power steering fluid replacement, we always recommend a complete flush.
In this light, here we’ll discuss how to flush power steering fluid in your BMW E46. And once again, you may find different ways to perform this task. However, depending on convenience and quickness, we have chosen the turkey baster method.
Extract Old Fluid
You might have already learned how to locate the power steering fluid reservoir and check the fluid level in your BMW E46. So, as you have found the reservoir, you have to extract the old fluid.
For this, you can use either a turkey baster, a pump machine, or a manual extractor depending on your preference. This is quite simple, you just have to insert the machine inside the reservoir and turn it on.
Put a container at the end of the line to store the old fluid. Don’t forget to wear protective clothing and goggles. And of course, your car should be parked on a flat surface.
Top Off the Reservoir with Fresh Fluid
As you have completely extracted the old fluid from the reservoir, you can use ATF from the reservoir.
Since, BMW doesn’t recommend using a funnel to avoid potential contamination, you will need to pour the fluid very slowly and very carefully.
Alongside, make sure you’re not overdoing it. For this, keep observing the dipstick on the reservoir cap. This will help you to track how much you have poured and whether it’s reached the recommended level.
Ensure Fluid Circulation by Starting the Car
Now it’s time to ensure the fluid is circulated properly in the steering system. For this, start your BMW and move the steering wheel from lock to lock. If everything seems perfect after a few minutes, you’re all set.
Do you have any other questions regarding the BMW E46 power steering fluid? If so, have a look at the FAQ section below.
How much does it cost to flush the power steering fluid in a BMW E46?
Flushing your BMW E46 power steering fluid will cost you around 90-100. This includes the price of the ATF and labor costs. However, if you do it yourself, hopefully, it will be done at 42$
How often should I flush my BMW E46 power steering fluid?
It can vary depending on how you drive, what fluid you’re using, road conditions, etc. Ideally, you should flush the fluid before any damaging symptoms appear. However, it’s good to have the fluid changed every 60,000,-80,000 miles.
How much power steering fluid does a BMW E46 need?
If you use Dexron III or Mercon ATF in your BMW E46 power steering system, you should pour at least 2 quarts and maximum 2.5 quarts.