How to change the engine oil in your car
Your car’s oil ensures your vehicle runs smoothly and efficiently, which is why regular oil checks should be considered an essential part of car maintenance.
How to guide
This guide is designed to give you all the information you could need to spot the signs of low oil levels, how to perform an oil change and where to dispose of old engine oil safely and responsibly.
Check engine oil
Before you start, use our Castrol product finder to select the best fully synthetic or semi-synthetic oil for your engine.
You will also need:
- Replacement oil
- Replacement oil filter
- Oil drain pan / container
- Oil filter and oil filter wrench
- Funnel
- Lint-free rags (to avoid contaminating your oil)
- Work / rubber gloves
- Safety glasses
- Jack stand and car trolley tack
- Wheel chocks
- Ratchet wrench and socket
- Torque wrench
- Sealing ring
- Crush washer
- Look for the drain plug – it is a large nut on your car’s oil pan, usually found at the bottom of the engine.
- Place your drain pan or container below the plug to collect the old oil.
- Using your socket, remove the drain plug and the old oil will flow into the oil drain pan. Be prepared for the oil to start to drain immediately.
- Once all the old oil is drained, reattach your drain plug securely using the socket wrench, but do not overtighten.
- Locate your oil filter - this is usually screwed onto the engine block.
- Use your oil filter wrench to loosen the oil filter, then use your hand to remove it.
- Replace it with your new oil filter – you should be able to screw it securely by hand.
- Locate and remove your car’s oil filler cap from the oil filler hole. It’s usually found at the top of the engine.
- Place your funnel into the oil filler hole and pour the replacement oil into it.
- Resecure the oil filler cap and clean any excess oil from the surface of your engine.
- Replace your oil filter cap and turn the car on for 30-60 seconds.
- Check for any leaks around the drain plug and the new filter.
- Turn off the engine for 10-15 minutes.
- Use your dipstick to check your new oil level, topping up until you reach the ‘full’ line on the dipstick.
- Remove the oil drain pan, carefully remove the jack stands and lower the car.
When an engine’s oil pressure is low, the oil is not moved around the engine enough to lubricate all the moving parts effectively. This can result in increased friction and potential damage to the engine.
The warning signs
- Your car’s oil warning light is on – this is the most obvious way to tell if there is a problem with your engine’s oil pressure.
- Scraping or clunking sounds coming from the engine – caused when moving parts of the engine rub together due to a lack of lubrication otherwise covered by optimum oil pressure levels.
- The smell of oil or burning – if you can smell either, it could mean a leak or the engine overheating and you should get your car serviced by a professional as soon as possible.
- It is important to maintain regular oil pressure checks to avoid the above issues, as left unchecked, they can result in leaks and breakdowns.
How to top up your engine oil
If dipstick tells you that your oil level is low, you should top up your engine oil as soon as possible.
The first step in doing this is to make sure you add the right oil. Your car's user manual can help with this, or you can also use our quick and easy Oil Finder tool.
Once you have your oil, make sure your car is again parked on level ground. Your engine should be cool, and you should wait at least 20 minutes to give the oil time to drain fully back into the sump.
1. Check the oil level again to see how much oil is required
2. Unscrew and remove the oil filler cap
Car engine oil filler cap
3. You should then add a small amount of fresh oil, ideally using a long-neck funnel, and then wait a minute or two for it to arrive in the sump
4. Check the level again using the dipstick, and keep adding oil in small amounts until you are happy with the level.
Bear in mind that over-filling is as bad for your engine as under-filling; so don't treat the high level mark as a target. It's best to aim for a little below this line.
Engine oil maintenance tips
We have created this guide about how often you should check your engine oil which offers all the information you need to know about engine oil maintenance and what factors can affect how often you should perform your checks.
Below is a list of common problems associated with engine oil.
- The ‘check oil’ or ‘check engine’ light is illuminated on your dashboard
- Unusual engine noises
- The smell of oil or burning
- Your car produces more exhaust smoke, or it is a different colour
- Your engine is overheating
Finding the right engine oil for your car
Many manufacturers now recommend fully synthetic engine oils due to the beneficial additives within their formulas. Fully synthetic engine oils are proven to emit fewer emissions, making them better for the environment while offering superior engine performance compared to semi-synthetic options. Find out more about the advantages of synthetic engine oil.
