Replacing 2006 Impreza Oil Pan: Easy Or Challenging?

Replacing the oil pan on a 2006 Impreza can be a challenging task, and many Subaru owners dread it. While it is possible to do it yourself, it may be easier to have a professional mechanic do it for you. The oil pan is located under the car and attached to the bottom of the engine. To replace it, you will need to lift the car and place it on jack stands to access the oil pan. You will also need various tools, including socket sets, extensions, wobble extensions, pliers, a car jack, a gasket remover tool, and a paint scraper. The process involves draining the oil, removing the old oil pan and gasket, cleaning the surfaces, applying a new gasket, and reinstalling the new oil pan. It is important to be careful during this process to avoid damaging the oil pan or the engine. The cost of replacing the oil pan on a Subaru Impreza can range from $305 to $569, depending on the model year and labor costs.

Removing the oil pan

Step 1: Prepare the Vehicle

• Park the car on a level surface and engage the parking brake.
• Place jack stands under the vehicle and raise it to gain access to the undercarriage.
• Locate the engine mount nuts under the car. They are typically 14mm nuts hidden behind the sway bar.
• Remove the TMIC (top-mount intercooler) and undo the factory dog bone mount. This will help free up the engine and transmission, making it easier to lift them later.
• Remove the 10mm bolt that holds the oil dipstick in place.

Step 2: Drain the Oil and Lift the Vehicle

• Drain the oil from the oil pan.
• Lift the car off the ground using a jack to provide adequate workspace underneath.
• Place jack stands in a safe area that holds the car stable without interfering with the work area.
• If needed, remove the exhaust manifold/header to create more working room.

Step 3: Remove the Dipstick Tube

• Remove the dipstick tube by leveraging it off with a pair of pliers. Be careful not to crush the tube.
• There are two o-rings inside the tube that can be tricky to remove. Once removed, they will stay with the hoses and behind the timing cover.

Step 4: Remove the Oil Pan Bolts

• All the bolts on the oil pan are 10mm and can be removed in any order.
• There are typically four bolts at the backside of the oil pan that are difficult to access. You may need to use extensions or a universal joint to reach them.

Step 5: Break the Gasket Seal

• Use a flat paint scraper or a gasket remover tool to break the gasket seal between the oil pan and the engine block.
• Tap the paint scraper through the gasket material with a mallet, twisting it back and forth to help release the hold.
• Alternatively, you can lightly strike the side of the oil pan to help break the gasket free, being careful not to damage the pan if you plan to reuse it.

Step 6: Remove the Oil Pan

• With all the bolts removed and the gasket seal broken, carefully remove the oil pan from the engine.
• If there are signs of leaking or damage, consider replacing the oil pan with a new one.

Remember to work carefully and refer to a trusted repair manual or seek assistance from a qualified mechanic if you are unsure about any steps.

Removing the dipstick tube

If the tube is stuck, there are a few approaches you can try. One is to apply some heat and lubrication to the cavity between the stuck dipstick and the tube, which should help to free up the dipstick and remove it. If the handle of the dipstick has broken off, you can try using a telescopic magnet pickup tool to reach into the tube and grab the metal part of the dipstick, then gently pull it out.

Another approach is to remove the oil pan from the bottom of the engine to gain access to the dipstick. You can use a rubber mallet to tap the dipstick upwards so that it appears at the top of the tube, then use pliers to pry it out. This method will also allow you to change the oil pan gasket and top up the engine with fresh oil.

If you are having trouble installing the new dipstick tube, you can try lubricating the seals and lining up the tube to the pan, then giving the top of the tube a strike with a rubber mallet to pop it into place.

Breaking the gasket seal

Before attempting to break the gasket seal, it is important to check for any leaks or damage to the oil pan and gasket. If there are any leaks, you will need to identify the source of the leak to ensure that it is coming directly from the oil pan gasket and not from another component.

When removing the oil pan and gasket, be sure to use the appropriate tools and follow the correct procedures to avoid damaging other components. It is also important to work in a clean and organised environment to avoid making mistakes during the process.

Once the oil pan and gasket are removed, you can break the gasket seal by prying or cutting it. Be careful not to damage the oil pan or surrounding components during this process. After breaking the gasket seal, it is important to clean the surfaces and remove any residual gasket material or adhesive before installing the new gasket.

It is recommended to consult a certified mechanic or refer to a repair manual for specific instructions on breaking the gasket seal and replacing the oil pan gasket on a 2006 Impreza. They will have the necessary tools, knowledge, and experience to perform the task correctly and avoid potential damage to your vehicle.

Cleaning the oil pan mating surface

To clean the oil pan mating surface, you will need to remove any old gasket residue and ensure the surface is free of oil and grime. Here is a step-by-step guide:

• Remove Old Gasket Residue: Use a plastic or composite gasket scraper to remove the remnants of the old gasket. Be careful not to use metal tools as they can damage the soft aluminum engine surface. Hold the scraper at a steep angle and scrape away the gasket, or try chipping at it by holding the scraper a few inches away and quickly jabbing at the gasket. Alternatively, you can use a 3M Bristle Disc attached to a rotary tool, but be gentle to avoid creating depressions in the aluminum.
• Clean the Surface: Once the majority of the gasket residue is removed, use a solvent like brake cleaner, lacquer thinner, or acetone on a clean rag to wipe down the mating surface. This will ensure that any residual oil or grime is removed. Be careful not to spray the solvent directly onto bearings or other parts.
• Final Inspection: After cleaning, inspect the mating surface to ensure it is smooth and free of any residue. Use a razor blade to clean off any remaining RTV (room-temperature vulcanized rubber) or old gasket material.

It is important to take your time and be thorough when cleaning the oil pan mating surface. Any remaining residue or contaminants can affect the seal of the new gasket and lead to oil leaks.

Reattaching the oil pan

Step 1: Clean the Oil Pan

Use a degreaser or detergent to thoroughly clean the oil pan, removing any sludge, grease, or oil residue. This step is crucial to ensure that the surface of the oil pan is free of contaminants that may interfere with the reattachment process.

Step 2: Inspect the Oil Pan for Damage

Before reattaching the oil pan, it is essential to inspect it for any signs of damage, such as cracks or metal shavings. If there are any cracks, you may need to repair them using an epoxy adhesive, as mentioned earlier. Make sure the oil pan is in good condition before proceeding to the next step.

Step 3: Prepare the Gasket

Obtain a new oil pan gasket that is compatible with your 2006 Impreza. Gasket materials vary depending on the type of metals they seal, so refer to your service manual or consult a mechanic to ensure you get the correct one. Clean all sealing surfaces and apply any necessary grease or sealants as per the gasket's instructions.

Step 4: Reattach the Oil Pan

Position the new gasket in place, following the instructions provided. Reattach any accessory brackets and bolts that were previously removed. Torque the oil pan bolts to the specified tension in a spiral pattern, starting from the center. This step ensures that the oil pan is securely fastened to the engine.

Step 5: Refill and Inspect

Refill the crankcase with new engine oil. Start the engine and inspect for any signs of leaks around the oil pan and gasket. Ensure that the oil level is sufficient by checking the dipstick. If no leaks are detected and the oil level is correct, you have successfully reattached the oil pan.

It is important to note that this process may vary slightly depending on the specific make and model of your vehicle. Always refer to the service manual for detailed instructions and safety precautions. If you are uncomfortable performing this task yourself, it is recommended to consult a certified mechanic.

Frequently asked questions