Tightening The Oil Pan: 08 328I Torque Techniques

The BMW E90 328i is notorious for leaking oil from areas such as the oil pan gasket, oil filter housing gasket, and valve cover gasket. To fix a leaking oil pan gasket, you will need a torque wrench capable of going as low as 8nm, torx bits and torx socket sets, a socket set, jack stands, and a low-profile floor jack. After jacking up the car and draining the oil, you will need to remove the front wheels, unplug the headlight-leveling sensor, and remove the plastic underbelly covers. Next, remove the bolts securing the engine cover and use the tow hook to screw into the driver-side front corner of the cylinder head. Set up the engine support bar and unbolt the triangular bar beneath the sub-frame, then remove the bolts from each engine mount. Place a floor jack under the large rear section of the subframe and remove the bolts holding the subframe. Lower the subframe and disconnect the plug and ground wire for the oil level sensor. Remove the bracket protecting the fuel and brake lines, then unbolt the power steering hose and unclip the AC pipe. Remove all oil pan bolts, the oil pan, and clean the oil pan and engine block. Reinstall the oil level sensor and, once everything is clean, use zip ties to hold the gasket to the oil pan for installation. Put the oil pan in place and reconnect the oil return tube, then put the bolts in the pan, torquing them to 8nm + 90°. Finally, raise the subframe, tighten all bolts, and put everything else back together in reverse order.

Jack up the car and drain the oil

Jacking up your car is a necessary step in changing the oil in your 08 328i. Here is a detailed, step-by-step guide to help you do it safely and effectively:

Step 1: Locate the Jacking Points

Before you start, it's important to consult your car manual or an online resource to locate the recommended points for lifting your specific vehicle. Most cars should have these manuals when they are purchased. If you don't have access to one, auto parts stores usually carry them, and they are easy to find online.

Step 2: Ensure the Car Will Not Move

Make sure your emergency brake (or handbrake for older models) is engaged. For added safety, place some blocks or bricks behind the back wheels as an extra precaution.

Step 3: Start Jacking

Begin jacking from the front of your vehicle. Slowly pump the jack until both front tires are lifted off the ground, then stop and double-check the placement. Ensure the jack is level and propped up with blocks if needed. Look at the vehicle from all angles to confirm there are no issues such as leaning too far forward or backward. Once confirmed, continue applying pressure until the wheels are raised securely off the ground.

Step 4: Place the Car on Jack Stands

Support the front of your car by placing jack stands directly under its frame, making sure they are at least as high as you want to climb underneath comfortably. Refer to your car manual for the specific placement of the jack stands. Support each front wheel with a stand, then turn the handle slowly and make minor adjustments before lowering the full weight onto the stands.

Now that your car is securely jacked up, you can proceed to drain the oil. Place a drain pan or container under the oil pan drain plug to catch the used oil. Locate the oil pan drain plug, which is typically at the bottom of the oil pan. Using a socket wrench or a similar tool, loosen and remove the drain plug. Allow the oil to drain completely, which may take several minutes.

Once the oil has drained, replace the drain plug and tighten it securely. You may also want to replace the oil filter, which is usually located near the drain plug. Make sure to have a new oil filter gasket on hand if needed. After ensuring that the drain plug and oil filter are secure, you can lower the vehicle by slowly turning the jack handle in the opposite direction until the tires are back on the ground.

Remember to always exercise caution when working on your car, and refer to your car's manual or seek professional advice if you have any questions or concerns.

Remove wheels and underbelly covers

To remove the wheels and underbelly covers of your 08 328i, follow these steps:

First, you will need to jack up the front of the vehicle and safely support it. You can refer to this video for a visual guide on jacking up your BMW: https://www.youtube.com/watch?v=Lyxj2kuOBoQ.

Once the car is securely raised, you can begin removing the wheels. Use a lug wrench or an impact wrench to loosen the lug nuts. You may need to apply some force, as they are typically tightened to a high torque specification. Be sure to place the lug nuts in a safe place so that you can reuse them when you reinstall the wheels.

With the lug nuts removed, you can now take off the wheels. Gently pull the wheel away from the car, being careful not to strain your back. Set the wheels aside in a safe place.

Now, you will remove the underbelly covers, also known as the engine and transmission splash shields. These are made of plastic and are held in place by small bolts. Working from under the vehicle, use an 8mm socket or nut driver to remove the splash shield fasteners. There are seventeen fasteners for the engine splash shield and four for the transmission splash shield. Detach any retaining clips and carefully remove the shields from the vehicle.

If you need access to components further back, you may also need to remove the small splash shield behind the transmission. This requires removing two additional fasteners.

Additionally, if your vehicle is all-wheel drive, there is one additional reinforcement plate that may need to be removed. This plate is attached with six 16mm fasteners.

With the wheels and underbelly covers removed, you will now have better access to the underside of the engine and transmission for servicing. Remember to reinstall the covers and wheels when you have completed your work.

Remove engine cover bolts

To remove the engine cover bolts of a 2008 328i, you will need a set of sockets (8mm), a T40 Torx socket, a flathead screwdriver, and a Phillips-head screwdriver. The process should take around 45 minutes.

First, work with a cool engine and open the engine hood. Remove the six 8mm cabin microfilter lid fasteners. Then, lift the lid and remove it from the cowl. Now, working at the right side of the engine compartment, remove the air quality (AUC) sensor by rotating the sensor counterclockwise and pulling it out of the cowl. Next, unclip the wiring harness from the cowl and lay it aside.

Then, working on the right side of the engine compartment, unclip and remove the E-box cover. There are two clips to release. Detach the rubber tab and remove the E-box cover from the vehicle.

Now, working on the left side of the engine compartment, unclip and remove the brake fluid cover. This is similar to removing the E-box cover.

Next, working at the center of the wiper cowl, open the wiring harness cover by detaching the locks, then pull the wiring harness cover off and remove. Pull the wiring harness and battery cable out of the bracket and lay them aside.

Now, detach the bracket for the wiring harness that runs under the cowl. Use a flathead screwdriver and lever the bracket open through the top of the cowl.

Working on the left side of the cowl, remove the rubber tab, then remove the 8mm fastener. Repeat these steps for the right side of the cowl.

Finally, pull the housing up and forward to remove it from the vehicle. Remove the five T40 Torx engine cover fasteners by rotating them 90° counterclockwise, then remove the cover from the engine.

Set up an engine support bar and unbolt the subframe

To set up an engine support bar and unbolt the subframe, follow these steps:

Firstly, purchase an engine support bar. These are available from a range of automotive retailers and online stores. Engine support bars are used to keep the engine stable while the subframe is removed. They typically feature a two-point lift holder and dual hooks to attach to the engine.

Next, place the engine support bar in the engine bay. Ensure it is securely attached to the engine and that the engine weight is fully supported.

Now, you can safely jack up the vehicle and remove the subframe. Place a trolley jack under the vehicle, ideally using a block of wood to spread the load and prevent damage to the oil pan. Once the vehicle is secure, you can begin to unbolt the subframe.

Start by unbolting the engine mount and jacking up the engine by the alternator lower bracket. Then, unbolt the sump and remove it from the engine block. Be careful not to damage the sump gasket during this process. Next, undo the pressure relief valve and unbolt the oil pickup. With the engine supported, carefully lower the subframe from the vehicle.

It is important to note that this process may vary depending on the specific vehicle and engine configuration. Always refer to a qualified mechanic or a vehicle-specific repair guide for detailed instructions.

Disconnect the oil level sensor

Disconnecting the oil level sensor is a fairly straightforward process, but it requires careful attention to detail. Here is a step-by-step guide on how to do it for your 2008 BMW 328i:

Step 1: Prepare the Vehicle

• Park your car on a level surface and engage the parking brake.
• Raise the front of your vehicle and support it securely on jack stands.
• Locate the oil level sensor. It is usually found in the oil pan, near the engine. Refer to your car's repair manual for the exact location.

Step 2: Drain the Oil

• Place a suitable container under the engine oil pan to catch the draining oil.
• Remove the engine oil drain plug and allow the oil to drain completely.
• Once drained, reinstall the engine oil drain plug and tighten it securely.

Step 3: Disconnect the Oil Level Sensor

• Clean the area around the oil level sensor thoroughly.
• Disconnect the electrical connector from the oil level sensor. It is usually a simple plug-and-socket connection.
• Remove the mounting nuts or bolts holding the oil level sensor in place. There are typically three 10mm nuts or bolts.
• Carefully remove the oil level sensor from the oil pan, being prepared to catch any dripping oil.

Step 4: Clean and Inspect

• Clean the oil level sensor mounting area thoroughly.
• Inspect the O-ring on the sensor. If it is stuck to the oil pan, gently pull it down and remove any remaining parts of the O-ring.
• If there is any rust or corrosion around the sensor, it may be necessary to repair or replace the oil pan.

By following these steps, you will be able to successfully disconnect the oil level sensor on your 2008 BMW 328i. Remember to work with a cool engine and always wear eye protection and gloves for your safety.

Frequently asked questions