Over time, valve stem seals can start to leak due to wear and tear. The high stress caused by fluctuating temperatures or mechanical pressure makes the material porous, hard, or brittle. This can cause the valve stem seal to crack or break, resulting in leaks.
Symptoms of a faulty valve stem seal
Oil leakage: You see oil stains under the car or oil drips on the ground.
Topping up oil more frequently: If you notice that you need to top up your oil more often than usual, this could indicate a leaking valve stem seal.
Oily spark plugs: The top of the spark plugs feels oily.
Oil pressure warning light: In case of prolonged problems, the oil pressure warning light may illuminate.
Adjusting valve clearance
Adjusting the valve clearance is an important task to keep the engine running smoothly. Here are the general steps to adjust the valve clearance:
Disassembly: Remove the rocker cover to access the valve stem seals.
Determine compression stroke: Rotate the engine by hand until the piston of the relevant cylinder is at the top of its compression stroke (both valves are closed).
Measure with a feeler gauge: Place a feeler gauge between the valve stem seal and the valve rocker arm. The correct clearance depends on the make and model of the car, so consult the specifications in the manual.
Adjust: Turn the valve adjuster screw or nut to achieve the correct clearance. Recheck with the feeler gauge.
Repeat for other cylinders: Repeat this process for all valve stem seals.
Reassembly: Refit the rocker cover.
Remember that specific instructions may vary depending on the make and model of your car.
Order your valve stem seal at Winparts
You can easily find the right engine parts for your car using the registration number or car model. You can simply enter these on the website and the correct parts will be shown. At Winparts, in addition to valve stem seals, you will also find other engine parts, such as: cylinder heads, oil pumps and intake manifolds. View our webshop and order today.