Key points
- The transmission dipstick on the E90 is usually located on the passenger side of the engine bay, near the front of the transmission.
- It’s a long, metal rod with a handle that you can pull out to check the fluid level.
- Start the engine and let it run for a few minutes to bring the transmission fluid to operating temperature.
Are you a proud owner of a BMW E90 and want to ensure your automatic transmission is running smoothly? Checking the transmission fluid level is a crucial maintenance task that can help prevent costly repairs down the line. While many modern vehicles have sealed transmission systems that require infrequent fluid checks, the BMW E90 is an exception. This guide will walk you through the process of checking your E90’s automatic transmission fluid, providing clear instructions and helpful tips.
Why Checking Transmission Fluid is Important
Automatic transmission fluid (ATF) plays a vital role in your car’s transmission system. It acts as a lubricant, coolant, and hydraulic fluid, enabling smooth gear changes and protecting the transmission components from wear and tear. Over time, ATF can become contaminated with debris, lose its viscosity, and degrade in performance. This can lead to sluggish shifting, transmission slippage, and even complete transmission failure.
Regularly checking the transmission fluid level helps you catch potential problems early on. If the fluid is low, you can top it off with the correct type of ATF. If the fluid is discolored, smells burnt, or has a gritty texture, it may indicate a more serious issue that requires professional attention.
Preparing for the Check
Before diving into the process, gather the necessary tools and ensure your vehicle is parked on a level surface. Here’s what you’ll need:
- Clean rags or paper towels: To wipe away any spills or excess fluid.
- A dipstick: The E90’s transmission dipstick is located near the transmission pan. It’s typically a long, metal rod with a handle.
- A flashlight: To illuminate the dipstick and fluid level markings.
Locating the Dipstick
The transmission dipstick on the E90 is usually located on the passenger side of the engine bay, near the front of the transmission. It’s a long, metal rod with a handle that you can pull out to check the fluid level.
Here’s how to find it:
1. Open the hood: Release the hood latch and prop it open.
2. Look for the transmission pan: It’s a large metal pan located near the front of the engine.
3. Locate the dipstick: The dipstick will be sticking out of the transmission pan, usually near the front. It may have a yellow or orange handle.
Checking the Fluid Level
Once you’ve located the dipstick, follow these steps to check the fluid level:
1. Warm up the engine: Start the engine and let it run for a few minutes to bring the transmission fluid to operating temperature.
2. Park on a level surface: Ensure the vehicle is parked on a level surface to get an accurate reading.
3. Pull out the dipstick: Gently pull out the dipstick.
4. Wipe the dipstick clean: Use a clean rag or paper towel to wipe off any fluid on the dipstick.
5. Reinsert the dipstick: Push the dipstick all the way back into the tube.
6. Pull out the dipstick again: Remove the dipstick a second time.
7. Check the fluid level: Look at the dipstick and observe the fluid level. It should be somewhere between the “Full” and “Low” markings.
Interpreting the Results
Once you’ve checked the fluid level, it’s important to understand what the reading means.
- Fluid level within the “Full” and “Low” markings: This indicates that the transmission fluid level is within the normal range.
- Fluid level below the “Low” mark: This means the transmission fluid level is low and needs to be topped off.
- Fluid level above the “Full” mark: This indicates that the transmission fluid level is too high. It’s important to consult a mechanic to determine the cause of the overfilled transmission.
Topping Off the Transmission Fluid
If the fluid level is low, you can top it off with the correct type of ATF. Here’s how:
1. Locate the transmission fluid fill port: It’s usually located on the top of the transmission pan. It’s a small, round hole with a cap.
2. Remove the fill port cap: Use a wrench to remove the cap.
3. Add ATF slowly: Pour the correct type of ATF into the fill port, checking the dipstick periodically to avoid overfilling.
4. Replace the fill port cap: Once the fluid level is within the normal range, replace the fill port cap.
When to Consult a Mechanic
While checking the transmission fluid level is a simple task, there are certain situations where you should consult a mechanic:
- The fluid is discolored: If the transmission fluid is dark brown, black, or has a burnt smell, it may indicate severe wear and tear on the transmission.
- The fluid has a gritty texture: This could indicate metal shavings or other debris in the transmission, which can damage the transmission components.
- The transmission is slipping: If the transmission is slipping or shifting erratically, it’s a sign of a potential problem that requires professional diagnosis.
Taking Care of Your E90’s Transmission
Keeping your BMW E90’s transmission in good working order requires more than just checking the fluid level. Here are some additional tips:
- Regularly change the transmission fluid: The manufacturer’s recommended service interval for transmission fluid changes is typically around 60,000 miles. However, if you frequently drive in harsh conditions, such as towing heavy loads or driving in extreme temperatures, you may need to change the fluid more often.
- Avoid harsh driving: Aggressive driving habits, such as sudden acceleration and braking, can put stress on the transmission and shorten its lifespan.
- Use the correct type of transmission fluid: Always use the type of ATF specified by the manufacturer for your E90. Using the wrong type of fluid can damage the transmission.
Final Thoughts: Keeping Your Transmission Healthy
Checking the transmission fluid level is a simple but essential maintenance task that can help prevent costly repairs. By following the steps outlined in this guide, you can ensure that your BMW E90’s transmission is running smoothly and efficiently.
Remember, if you notice any unusual symptoms, such as slipping, jerking, or strange noises, don’t hesitate to consult a qualified mechanic for a proper diagnosis and repair.
Top Questions Asked
Q: How often should I check my E90’s transmission fluid?
A: It’s a good practice to check the fluid level every 3,000 miles or every 3 months, whichever comes first. However, if you notice any unusual symptoms, such as slipping or jerking, it’s essential to check the fluid immediately.
Q: What type of transmission fluid should I use for my E90?
A: The correct type of ATF for your E90 will depend on the specific model year and transmission type. Consult your owner’s manual or a qualified mechanic to determine the appropriate fluid.
Q: Can I top off the transmission fluid myself?
A: Yes, you can top off the transmission fluid yourself if the level is low. However, if the fluid is discolored, smells burnt, or has a gritty texture, it’s best to consult a mechanic.
Q: What happens if I overfill the transmission fluid?
A: Overfilling the transmission fluid can cause excessive pressure, leading to leaks, damage to seals, and even transmission failure. It’s crucial to avoid overfilling the transmission.