How Can You Tell What Type of Fluid Is Leaking from Your Car?

Most vehicles require several fluids to keep the engine and gearbox functioning properly. How can you tell whether a roadside fluid spill is engine oil or something else?

There are five or six possibilities for leaking fluids, depending on the age of your car:

1.      Engine Oil - This is normally light, dark brown, or even black in colour, unless it has recently been changed. If it's fresh, it smells like plastic; if it's old, it smells like frying oil. If you're looking at it from the street, it'll be black in colour and, when wet, it'll seem to be a rainbow from certain angles.A heavy engine oil leak will result in a MOT failure so before booking your next MOT testing service, schedule an appointment with a professional mechanic to diagnose where the oil leak is coming from and have this fixed as soon as possible.

2.      Fuel (petrol or diesel) - Because of their unique smells, petrol and diesel are typically very straightforward to distinguish. In little volumes, petrol tends to dry out and evaporate fast. It can turn a golden-brown tint when moist. Diesel is a deeper hue with a blue tint to it.

3.      Transmission Fluid - When fresh, transmission fluid can be a bright red colour, but it can also have the colour and viscosity of engine oil. It can be difficult to tell the difference between it and engine oil, and it may only become apparent once you locate the source of the leak. Check MOT status and have leaking transmission fluid investigated and repaired. This is because if your car in undergoing a MOT test and the tester is having difficulties carrying out the necessary checks due to not being able to change gears, the tester can either fail the MOT test or fully refuse to carry out the MOT until the fault is rectified.

4.      Engine Coolant - This comes in a variety of colours, including pink, blue, and green. Check to verify whether the colour of the coolant top-up container matches that of the leaking fluid. If the fluid level in the container is low, it might indicate a leak in the coolant system. The fragrance of coolant, which is generally sweet like candy floss, can also be used to identify it.

5.      Brake Fluid - Brake fluid is a light brown tint that may be virtually transparent at times. It may have a different odour depending on its age. Check the brake fluid reservoir if you suspect a brake fluid leak. If the fluid level is really low, you should explore more for your own safety.If your car's MOT history check shows that it previously failed due to the braking system, the issue might have been leaking or low brake fluid. Examine your repair invoices (if any are available) to determine the specific nature of the problem.

6.      Power steering fluid (ATF) - This is a kind of fluid that is utilised in majority vehicles nowadays. When it's young, it's red, but as it ages, it turns brown. It has a somewhat burned aroma and a thick consistency. A power steering fluid leak is frequently visible near the hose connectors or the top-up container. Check MOT history of your car to see whether it has previously failed owing to the steering system. If the power steering fails, the MOT tester may need to conduct a road test to see if the steering is compromised. Only when a component, joint, or seal fails will a power steering fluid leak will result in a MOT failure.

What Causes Oil Leaks in Cars?

Your car's oil leak might be caused by a number of factors:

1.      Failure of a rubber seal or gasket is the most prevalent cause of oil leaks in vehicles. Rubber seals are employed in a variety of engine sections when two components meet. Engines may grow extremely hot, and some sections of the engine are subjected to extremely high pressures. Rubber components will harden and break over time as a result of the engine's ongoing heating and cooling.The oil sump gasket, the oil sump bung (nut), the oil filter housing (or rubber seal if it's a screw on filter type), and the oil filler cap are all common spots for seals to fail and oil to leak from. Oil leaks from the head gasket are also possible, although the oil is more likely to seep into the coolant rather than out of the engine. The gearbox or transmission are two more sites where leaks might occur. These can leak at the sump or at the engine's connection.

2.      Parts that aren't properly installed might also leak. The seal will leak if a replacement component is not tightened adequately. Overtightening the seal might potentially cause it to fail. This is why using a torque wrench when working on your car is critical. Bolts used on the oil sump or the cylinder head, for example, must be torqued to a certain tightness and tightened in a specified order. If you don't, you'll almost certainly end up with a leak.

3.      The car's undercarriage is damaged. A speed bump or a pothole can sometimes trigger a leak. Leaks might be caused by damage to the oil sump or the underside of the gearbox.

4.      Oil filter that has come loose. The screw-on, canister oil filter is still used in many autos. When fitted against the engine, this type of oil filter features a rubber gasket that forms a seal. If the oil filter is not replaced on a regular basis, this seal will wear out and leak or cause the oil filter to loosen.This is more prevalent than you would believe. Oil change intervals are lengthening, which implies oil filters aren't being replaced as frequently. It's critical to select a high-quality oil filter if you're changing the oil in your car yourself. There are 'extended life' oil filters on the market that can properly filter the oil for longer lengths of time, and most of them come with an updated rubber or silicone gasket that can last longer as well.