Bangkok: Five common causes of oil leaks in cars are being shared on social media, including worn engine seals and gaskets, and leaking power steering pumps. Are these claims true? Find out in the "Sure Before Sharing" series: Motor Check.
According to Thai News Agency, the "Sure Before Sharing" center verified the information with Dr. Napadol Klinthong, an expert in automotive technology and electric vehicles from Bangkok Thonburi University. An oil leak under a car is a nightmare that many car owners want to avoid. Not only does it leave annoying stains on the ground, but if left untreated, it can escalate into a major problem, causing engine damage and costly repairs.
5 Common Causes of Car Oil Leaks
1. Engine seals and gaskets are worn out.
Cause: After prolonged use, rubber seals and gaskets are exposed to alternating heat and cold, as well as chemical reactions with oil. This causes the rubber to harden, deteriorate, and lose its sealing properties, allowing oil to leak out.
2. The oil filter is loose or overtightened.
Cause: The oil filter area has a rubber seal called an "O-ring" that prevents leakage. If the threads are too loose, oil will leak. Conversely, many people are unaware of this and try to tighten it as much as possible, overtightening it. This causes the O-ring to be compressed and deformed, losing its elasticity and causing oil leaks as well. (Professional mechanics use a torque wrench to ensure the correct tightening ratio.)
3. The drive shaft boot is torn.
Cause: This is commonly found in front-wheel drive vehicles. The drive shaft boot stores a special liquid grease for lubrication. If the drive shaft boot deteriorates, cracks, tears, or leaks, when the wheel rotates at high speed, centrifugal force will splatter the grease (which is black or green) onto the gearbox and undercarriage.
Caution: If this symptom is observed, immediate repair is necessary. If left untreated and the grease dries out, the driveshaft will experience severe wear and become a major problem.
4. The power steering rack is leaking and worn.
Cause: When the power steering rack deteriorates, power steering fluid will leak from the tie rod boot, causing the fluid to drip out and potentially deteriorate the boot.
Signs of trouble: The power steering fluid level in the reservoir disappears without explanation, the steering wheel becomes heavier, and an unusual noise is heard when turning the steering wheel.
5. The power steering pump is leaking.
Cause: The power steering pump, located at the top (whether belt-driven or electric), may be leaking, either the pump itself or the rubber hose on the oil inlet/return side. If there is a leak, oil will be clearly visible on the ground.
Observation: The power steering fluid level is low, and the pump will make a distinct whining noise while operating.
Additional precautions: Why is the oil still leaking even after replacing all the seals?
Experts have provided interesting additional information: Often, even after car owners have had the valve cover seals, crankshaft seals, or camshaft seals replaced, the engine still experiences oil leaks.
A hidden cause that mechanics often forget to check is the "positive crankcase ventilation valve" (PCV Valve). This valve is located in the valve cover and connected to the intake manifold. If this valve becomes clogged and doesn't open to release engine oil pressure, the pressure built up inside the engine will force oil to leak through the various rubber seals. Even if you replace the seals multiple times, the leak won't stop if the PCV Valve is the root cause.
In summary: Oil leaks, regardless of the source, are a warning sign that car owners should not ignore. If you notice oil drips under your vehicle or oil stains on the engine, you should have your car inspected by a qualified mechanic immediately to address the problem early and prevent small issues from escalating into major, costly problems.