Engine Oil Filter Change Guide

The engine oil filter is a crucial component in any vehicle's lubrication system, working diligently to trap contaminants and ensure that only clean oil circulates throughout your engine. Over time, this filter becomes saturated with impurities, diminishing its effectiveness and potentially leading to increased wear and tear on vital engine parts. While often perceived as a complex task, changing your engine oil filter, especially on a diesel engine like the Type 668, is a straightforward process that any car owner can undertake with the right guidance. This comprehensive guide will walk you through each step, from identifying the filter to selecting the correct oil, ensuring your engine remains in peak condition.

Locating the Engine Oil Filter (Type 668 Diesel)

The engine oil filter on a Type 668 diesel engine is typically very easy to find within the engine compartment. You'll notice a distinctive housing, often cylindrical, with a prominent nut or hex fitting on the top. This housing contains the oil filter element itself. Its accessibility is designed to facilitate regular maintenance, making it a readily identifiable part of your engine's service points.

Essential Tools and Supplies

Before you begin, gathering the necessary tools and supplies will make the process smoother and more efficient. Here's what you'll likely need:

• New Engine Oil Filter: Ensure it's the correct part number for your Type 668 diesel engine. It will usually come with new sealing rings.
• New Engine Oil: Specifically, an oil that meets the MB 229.31 specification (low ash). Mobil 1 ESP 5W-30 is a suitable option for UK-based vehicles.
• Oil Filter Wrench or Socket Set: To unscrew the filter housing. The size of the nut on top will determine the correct tool.
• Drain Pan: To collect the old engine oil.
• Funnel: For adding the new engine oil.
• Gloves: To keep your hands clean.
• Rags or Paper Towels: For cleaning up spills.
• Torque Wrench: If you are draining oil from the sump plug, to ensure it's tightened to the correct specification (30 Nm for the stud).
• Oil Drain Plug Washer (if applicable): It's often recommended to replace this with each oil change.

Step-by-Step Guide to Changing the Oil Filter

Step 1: Prepare the Vehicle and Drain Old Oil

For optimal oil flow, it's best to drain the engine oil when it's at operating temperature. However, be cautious as the oil will be hot. You have two primary methods for removing the old oil:

• Draining via the Sump Plug: Locate the oil sump plug at the bottom of the engine's oil pan. Place your drain pan beneath it and carefully unscrew the plug. Allow all the old oil to drain out completely. Once drained, clean the sump plug and screw it back in. If you're replacing the sump plug stud, ensure it is tightened to the specified torque of 30 Nm. Never overtighten the sump plug, as this can damage the oil pan threads.
• Suction via the Dipstick Tube: Alternatively, you can use an oil extractor pump to remove the old oil through the dipstick tube. This method can be less messy, especially if accessing the sump plug is difficult. Insert the extraction tube down the dipstick tube until it reaches the bottom of the oil pan and pump out the old oil into a suitable container.

Step 2: Remove the Old Oil Filter Housing

With the old oil drained or mostly drained, you can now tackle the oil filter. Identify the filter housing with the nut on top. Using your oil filter wrench or the appropriate socket, carefully unscrew the housing. It's important to note that there might be some residual oil in the housing, so be prepared for a small amount to spill out. Place your drain pan underneath to catch any drips.

Step 3: Replace the Filter Element and Seals

Once the housing is unscrewed, you can pull out the old oil filter element. You will notice that your new filter comes with two new sealing rings. It is absolutely essential to replace these old seals with the new ones provided. One seal typically goes around the edge of the filter housing cap, and the other fits into a groove on the housing itself. Carefully remove the old seals and clean the housing thoroughly. Then, fit the new seals into their correct positions, ensuring they are seated properly. Lubricating the new seals with a little bit of new engine oil can help them seat correctly and prevent damage during installation.

Step 4: Install the New Oil Filter Housing

Insert the new oil filter element into the housing, ensuring it sits correctly. Screw the housing back into place by hand first to avoid cross-threading. Once hand-tight, use your oil filter wrench or socket to tighten it. Do not overtighten. The housing usually has a marking indicating the correct tightening procedure, often a specific torque setting or a turn after hand-tight. Consult your vehicle's manual for the precise tightening instructions.

Step 5: Refill with New Engine Oil

Now it's time to add the new engine oil. Open the bonnet and locate the oil filler cap, usually marked with an oil can symbol. Using a funnel, carefully pour in the correct amount of new engine oil. The exact quantity will depend on your specific engine model, so refer to your vehicle's owner's manual. For the Type 668 diesel, ensure you use oil that meets the MB 229.31 specification.

Step 6: Check Oil Level and Run the Engine

After refilling, replace the oil filler cap. Start the engine and let it run for a few minutes. Check for any leaks around the oil filter housing and the sump plug. Turn off the engine and wait for a few minutes for the oil to settle back into the sump. Then, check the oil level using the dipstick. Top up if necessary, but be careful not to overfill. The oil level should be between the minimum and maximum marks on the dipstick.

Choosing the Right Engine Oil for Diesel Engines

Diesel engines have different requirements compared to petrol engines, particularly concerning the oil's additive package. For your Type 668 diesel engine, it is crucial to use engine oil that meets the MB specification 229.31. This specification denotes a low-ash oil, which is essential for diesel engines fitted with diesel particulate filters (DPFs). These filters can be damaged by high-ash oils, which can lead to costly repairs. Always check the oil container; it must clearly state that it meets the MB 229.31 standard. Mobil 1 ESP 5W-30 is a widely available and suitable option in the UK that adheres to this specification.

Table: Common Oil Viscosities and Specifications

While the MB 229.31 specification is key, here's a general overview of oil viscosities and their suitability, though always prioritize the manufacturer's recommendation:

Note: Always refer to your vehicle's owner's manual for the recommended viscosity and specifications. The MB 229.31 specification is paramount for diesel engines with DPFs.

Frequently Asked Questions (FAQs)

Q1: How often should I change my engine oil filter?

It is generally recommended to change the engine oil filter every time you change the engine oil. This ensures that the new oil is protected by a clean filter, maximising its lifespan and effectiveness.

Q2: Can I use a generic oil filter if the specific one isn't available?

It's strongly advised against using a generic or incorrect oil filter. The filter is designed to fit and function precisely within your engine's system. Using the wrong filter can lead to poor filtration, leaks, or even damage to the engine. Always use the filter specified for your vehicle, especially for specialized requirements like the MB 229.31 specification.

Q3: What happens if I don't change my oil filter?

If you don't change your oil filter, it will eventually become clogged with contaminants. This can restrict oil flow, leading to insufficient lubrication of engine components. A clogged filter can also rupture, allowing unfiltered oil to circulate, causing significant internal engine damage. The oil pressure warning light might also illuminate.

Q4: Is it necessary to replace the sealing rings?

Yes, absolutely. The sealing rings are critical for preventing oil leaks from the filter housing. Old seals can harden and lose their elasticity, leading to leaks. Always use the new seals provided with your new oil filter.

Q5: What does 'low ash' oil mean for a diesel engine?

'Low ash' refers to the reduced content of sulfated ash, phosphorus, and sulfur (often referred to as SAPS) in the engine oil. These components can form deposits that clog the diesel particulate filter (DPF) over time, reducing its efficiency and potentially causing irreversible damage. Low SAPS oils are specifically formulated to protect modern exhaust after-treatment systems, including DPFs.

Conclusion

Changing your engine oil filter is a fundamental aspect of vehicle maintenance that, when done correctly, contributes significantly to the longevity and performance of your diesel engine. By following these detailed steps, understanding the importance of the correct oil specification (MB 229.31 for your Type 668 diesel), and using the right tools, you can confidently perform this task yourself. Regular maintenance, including timely oil and filter changes, is the most effective way to prevent costly repairs and ensure your vehicle runs smoothly for years to come. Remember to always consult your vehicle's owner's manual for specific recommendations and torque values.