BMW 335i Oil Filter Housing Gasket Replacement Guide

Nov 18, 2025 by Alex Braham 53 views

Hey guys! If you're a BMW 335i owner, you might eventually run into the dreaded oil filter housing gasket leak. It's a pretty common issue, but don't worry, it's something you can tackle yourself with the right tools and a bit of patience. This guide will walk you through the entire replacement process, step-by-step, making it super easy to follow along. So, grab your wrenches, and let's get started!

Understanding the Oil Filter Housing Gasket

The oil filter housing gasket in your BMW 335i is a critical component responsible for sealing the oil filter housing to the engine block. Its primary job is to prevent oil leaks, ensuring that the engine maintains proper oil pressure and lubrication. Over time, this gasket can degrade due to exposure to high temperatures and harsh chemicals in the engine environment. When the gasket fails, it leads to oil leaks, which can cause a variety of problems, from minor annoyances to serious engine damage. Recognizing the symptoms of a failing gasket early can save you a lot of headaches and money down the road.

One of the main reasons the oil filter housing gasket fails is the material it’s made from. Typically, these gaskets are made from rubber or a similar synthetic material. These materials are prone to hardening, cracking, and losing their elasticity over time, especially when exposed to the constant heat cycles of an engine. The repeated heating and cooling cause the gasket to become brittle, making it less effective at maintaining a tight seal. Additionally, the chemicals present in engine oil can gradually degrade the gasket material, further accelerating its deterioration. Regular oil changes can help mitigate this issue by ensuring that the oil is clean and less corrosive, but eventually, the gasket will need to be replaced.

The location of the oil filter housing also contributes to the gasket's vulnerability. Positioned on the engine block, often near the top or front of the engine, the housing is exposed to significant heat from the engine itself. This constant exposure to high temperatures accelerates the degradation of the gasket. Furthermore, the oil filter housing is subjected to vibrations from the engine, which can also weaken the gasket over time. These vibrations, combined with the heat and chemical exposure, create a perfect storm for gasket failure. Therefore, it's not uncommon for BMW 335i owners to experience oil filter housing gasket leaks as their vehicles age.

Ignoring a leaking oil filter housing gasket can lead to several serious consequences. First and foremost, oil leaks can cause a drop in engine oil pressure. Proper oil pressure is essential for lubricating the engine's moving parts, and a decrease in pressure can lead to increased wear and tear, potentially causing significant engine damage. Additionally, leaking oil can drip onto other engine components, such as the belts and hoses, causing them to degrade and fail prematurely. This can lead to even more extensive and costly repairs. Moreover, a significant oil leak can create a fire hazard if the oil comes into contact with hot exhaust components. Therefore, addressing an oil filter housing gasket leak promptly is crucial for maintaining the health and safety of your vehicle.

Symptoms of a Failing Oil Filter Housing Gasket

Spotting the symptoms early can save you from bigger headaches down the road. Here are some telltale signs:

Visible Oil Leaks: This is the most obvious sign. Look for oil pooling under your car or around the oil filter housing itself.
Oil Smell: A burning oil smell, especially after driving, is a strong indicator of an oil leak.
Low Oil Level: If you notice that your oil level is consistently dropping, even without visible leaks, the gasket might be the culprit.
Overheating: In severe cases, a significant oil leak can lead to overheating due to reduced lubrication.

Tools and Materials You'll Need

Before diving in, make sure you have everything you need. Here's a comprehensive list:

New Oil Filter Housing Gasket: Get a high-quality replacement gasket. OEM or reputable aftermarket brands are recommended.
New Oil Filter: Since you're already in there, it's a good idea to replace the oil filter.
Engine Oil: Have the correct type and amount of engine oil for your 335i on hand.
Socket Set: Including various sizes and extensions.
Torque Wrench: Essential for tightening bolts to the correct specifications.
Wrench Set: For various nuts and bolts.
Screwdrivers: Both flathead and Phillips head.
Pliers: For removing hoses and clips.
Drain Pan: To catch the old oil.
Funnel: For adding new oil.
Cleaning Supplies: Brake cleaner or degreaser to clean up any oil spills.
Rags or Shop Towels: Plenty of them for wiping up messes.
Gloves: To protect your hands.
Safety Glasses: To protect your eyes.

Step-by-Step Replacement Guide

Okay, let's get to the fun part! Follow these steps carefully, and you'll have your new gasket installed in no time.

Step 1: Prepare the Vehicle

Park your BMW 335i on a level surface and engage the parking brake.
Allow the engine to cool down completely. Working on a hot engine is dangerous and can cause burns.
Disconnect the negative terminal of the battery to prevent any electrical accidents.

Step 2: Drain the Engine Oil

Locate the oil drain plug underneath the engine.
Place the drain pan under the drain plug.
Using the correct size wrench, carefully remove the drain plug and allow the oil to drain completely.
Once the oil has drained, replace the drain plug with a new crush washer and tighten it to the manufacturer's recommended torque specification.

Step 3: Remove the Air Intake and Components

Remove the engine cover to access the oil filter housing.
Disconnect the mass airflow (MAF) sensor and any other electrical connectors attached to the air intake.
Loosen the hose clamps connecting the air intake to the throttle body and air filter housing.
Remove the entire air intake assembly and set it aside.

Step 4: Access the Oil Filter Housing

Carefully inspect the area around the oil filter housing for any visible leaks or damage.
Disconnect any hoses or electrical connectors that are attached to the oil filter housing.
Remove the oil filter cap using the appropriate socket or wrench.
Remove the old oil filter and set it aside. Note the direction of the filter for proper installation later.

Step 5: Remove the Oil Filter Housing

Locate the bolts that secure the oil filter housing to the engine block. These are typically E10 or E12 Torx bolts.
Using the correct size socket, carefully remove all the bolts. Keep track of their locations, as some may be different lengths.
Gently wiggle the oil filter housing to break it free from the engine block. Be prepared for some residual oil to spill out.
Carefully remove the oil filter housing and place it on a clean work surface.

Step 6: Clean the Mating Surfaces

Thoroughly clean the mating surfaces on both the oil filter housing and the engine block.
Use a plastic scraper or Scotch-Brite pad to remove any old gasket material or residue.
Wipe the surfaces clean with a lint-free cloth and brake cleaner or degreaser.
Ensure that the surfaces are completely clean and dry before proceeding.

Step 7: Install the New Gasket

Install the new oil filter housing gasket onto the oil filter housing. Make sure it is properly seated in the groove.
Apply a thin layer of silicone gasket sealant to both sides of the new gasket for added leak protection (optional but recommended).

Step 8: Reinstall the Oil Filter Housing

Carefully position the oil filter housing back onto the engine block.
Align the bolt holes and reinstall the bolts. Tighten them by hand initially.
Using a torque wrench, tighten the bolts to the manufacturer's recommended torque specification in a crisscross pattern. This ensures even pressure and a proper seal.

Step 9: Reinstall the Oil Filter and Cap

Install the new oil filter into the oil filter housing, making sure it is oriented correctly.
Install the oil filter cap and tighten it to the manufacturer's recommended torque specification.

Step 10: Reassemble Components

Reconnect any hoses or electrical connectors that were disconnected from the oil filter housing.
Reinstall the air intake assembly, making sure all connections are secure.
Reconnect the MAF sensor and any other electrical connectors.
Reinstall the engine cover.

Step 11: Add Engine Oil

Remove the oil filler cap on top of the engine.
Using a funnel, add the correct amount and type of engine oil to the engine.
Replace the oil filler cap.

Step 12: Final Checks and Startup

Reconnect the negative terminal of the battery.
Double-check all connections and ensure that everything is properly installed.
Start the engine and let it idle for a few minutes.
Check for any oil leaks around the oil filter housing and drain plug.
If there are no leaks, take the car for a short test drive and check again for leaks.

Tips and Tricks

Take Pictures: Before disconnecting anything, take pictures to help you remember how everything goes back together.
Label Everything: Use masking tape and a marker to label hoses and connectors.
Torque Specs: Always use a torque wrench and tighten bolts to the correct specifications to avoid damaging components.
Cleanliness: Keep your work area clean to prevent dirt and debris from entering the engine.

Common Mistakes to Avoid

Over-tightening Bolts: This can strip the threads or crack the housing. Always use a torque wrench.
Forgetting Connections: Double-check that you've reconnected all hoses and electrical connectors.
Using the Wrong Oil: Make sure you're using the correct type of oil for your 335i.

Conclusion

Replacing the oil filter housing gasket on your BMW 335i might seem daunting, but with this guide, you can totally do it! Just take your time, follow the steps carefully, and don't be afraid to ask for help if you get stuck. You'll save money and gain a better understanding of your car in the process. Happy wrenching!