Post Oil Change Checks: Don't Get It Wrong!

The Crucial Steps After an Oil Change

You've just had your vehicle's oil changed – a fundamental piece of maintenance for any car owner. However, the job isn't quite finished the moment the drain plug is tightened and the new oil is poured in. There are critical follow-up steps that many car owners overlook, leading to potential issues and misinterpretations of their vehicle's health. This guide will walk you through the essential checks and procedures to ensure your recent oil change is a success, safeguarding your engine and providing accurate insights into its performance.

Why Correct Oil Level Checking is Paramount

One of the most common pitfalls after an oil change is an incorrect assessment of the oil level. This mistake can lead to a host of problems, from under-lubrication, which causes excessive wear, to over-lubrication, which can damage seals and lead to oil leaks or even engine misfires. It's not just about adding oil; it's about adding the *right amount* and knowing precisely where the level should be. Many drivers mistakenly believe they are experiencing high oil consumption simply because the dipstick reading was inaccurate after the service.

The Correct Method for Checking Your Oil Level

Ensuring an accurate oil level reading requires a bit of precision. Follow these steps diligently:

• Park on a Level Surface: This is non-negotiable. Any incline can cause the oil to pool on one side of the sump, giving a false reading. Always ensure your vehicle is parked on a flat, level ground.
• Allow Time for Drainage: If the engine was running before the oil change, or if you've just completed the process, it's vital to wait. For a warm engine, allow at least five minutes after switching it off. This gives the oil time to drain back down into the oil pan from the engine's internal components.
• The Dipstick Technique: When you pull out the dipstick, resist the urge to immediately plunge it back in. Instead, hold it vertically, with the tip pointing downwards. This prevents any residual oil on the dipstick from 'tracking' back up, which would artificially inflate the reading. Wipe the dipstick clean, reinsert it fully, and then pull it out again to get your accurate reading.

The Two-Stage Top-Up Process

Here's where many get it wrong after an oil change. Instead of filling directly to the maximum mark, a more cautious approach is recommended:

1. Initial Fill to Minimum: After the oil change, fill the engine with oil only up to the minimum mark on the dipstick. This might seem low, but it's a deliberate step.
2. Run the Engine: Start the engine and let it run for a short period – just long enough for the oil pressure warning light to go out and for the new oil to circulate through the engine. This ensures the new oil fills the oil filter, oil cooler, and all the nooks and crannies within the engine.
3. Second Check and Top-Up: Switch off the engine and wait for a couple of minutes (similar to the initial waiting period) to allow the oil to settle back into the oil pan. Now, check the oil level again. You should see the level has risen. Top up the difference slowly, a little at a time, until the oil level reaches the maximum mark.

This staged approach prevents overfilling, which can be just as detrimental as underfilling.

Understanding Oil Consumption: A Precise Method

If you suspect your vehicle is consuming oil, it's essential to measure it accurately. Here’s a reliable method:

Step-by-Step Oil Consumption Measurement

1. Initial Setup: Ensure your vehicle is on a level surface. Check the oil level using the proper method described above and top up to the maximum mark. Make a note of the exact amount of oil added.
2. The Test Drive: Drive your vehicle for a specific distance, ideally 1000 km. During this period, try to maintain consistent driving conditions if possible, though general use is acceptable. Keep a record of your fuel consumption during this period.
3. Post-Test Check: After completing the 1000 km, park on a level surface again. Turn off the engine and wait for the oil to settle (as per the checking procedure). Check the oil level using the dipstick.
4. Calculate Consumption: Top up the oil to the maximum mark again. The quantity of oil you add to reach the maximum mark is your vehicle's oil consumption over the 1000 km.

A More Precise Calculation

For an even more refined measurement, you can relate oil consumption to fuel consumption. Divide the quantity of oil added (in litres) by the total fuel consumed (in litres) over the 1000 km. Compare this ratio to the manufacturer's specifications for your vehicle. Typical acceptable oil consumption can range from 0.5 to 1 litre per 1000 km, but this varies significantly between models and engine types.

Why Oil Quantities in Manuals Can Be Misleading

The amount of oil specified in your car's manual or workshop guides can sometimes be a source of confusion. It's crucial to understand the difference between:

• Initial Filling Quantity: This is the amount of oil required to fill an engine that is completely dry and has never had oil before, or after a major internal engine rebuild. This quantity includes filling the oil filter, oil cooler, and all internal passages.
• Oil Change Quantity: This is the amount of oil needed when simply changing the oil and filter on a normally functioning engine. A significant amount of old oil remains in the engine, stuck to pipes, channels, the oil cooler, oil pump, and various internal surfaces.

Consequences of Misinterpreting Quantities

If the larger 'initial filling' quantity is used during a routine oil change, the engine will be overfilled. Conversely, if the specified quantity for an oil change is too low, and the engine is started without checking the level, it may not have enough oil. If this low level isn't corrected promptly, it can be mistakenly attributed to oil consumption, leading to unnecessary worry and potentially incorrect maintenance decisions.

Common Mistakes to Avoid

Let's summarise the most frequent errors people make:

Frequently Asked Questions (FAQs)

Q1: How often should I check my oil level?
It's good practice to check your oil level at least once a month, and before any long journeys. If you notice the oil warning light illuminating on your dashboard, check it immediately.

Q2: My dipstick shows the oil is slightly above the maximum mark. Is this a problem?
Yes, overfilling with oil can be harmful. It can lead to increased pressure within the engine, potentially damaging seals and gaskets, causing leaks, and even leading to foaming of the oil, which reduces its lubricating properties. If you've overfilled, it's best to carefully drain a small amount of oil.

Q3: What type of oil should I use for my car?
Always refer to your vehicle's owner's manual for the correct oil viscosity (e.g., 5W-30, 10W-40) and specification (e.g., API SN, ACEA C3). Using the wrong type of oil can harm your engine.

Q4: Is it okay to top up with a different brand of oil?
Generally, yes, as long as it meets the manufacturer's specifications for viscosity and performance. However, it's best practice to stick to the same type and specification of oil if possible.

Q5: My car is old, is it normal for it to use oil?
Most engines consume a small amount of oil as part of their normal operation, especially as they age. The key is to know what is considered 'normal' for your specific vehicle by checking the manufacturer's recommended consumption rates. Regular checks and topping up are essential for older engines.

Conclusion

An oil change is a vital service, but the work doesn't end there. By understanding and meticulously following the correct procedures for checking your oil level and topping up, you not only ensure the immediate well-being of your engine but also gain accurate insights into its performance and potential issues like oil consumption. Take these extra few minutes after your next oil change; your engine will thank you for it with a longer, healthier life.

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