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Knowing the Reasons behind Your Faulty Nissan Xterra Oil Filler Cap
Your Nissan Xterra oil filler cap serves the very important purpose of keeping your engine oil in its proper place. You might not expect much damage to ensue from the breaking of such a small component, but a faulty oil filler cap can actually cause serious harm to your Xterra's engine. Avoid engine trouble by taking note of the following oil filler cap issues:
Engine oil leak
If your Xterra has developed an engine oil leak, you probably have a loose, cracked, or excessively tightened oil filler cap. Take a look under your hood and examine your oil filler cap for signs of wear and improper fitment. A loose oil filler cap might not be able to hold the pressure inside your engine oil tank and allow your engine oil to spill over. However, make sure that you don't tighten the oil filler cap too much, or you will risk damaging the O-ring seal and end up with an engine oil leak anyway.
Creamy, white deposits on the oil filler cap
Look at the underside of your oil filler cap and check if it has any white or cream-colored sludge. This light-colored buildup is a usual result of water mixing with your engine oil. While this is harmless for the most part, it can also mean that you have a cracked or worn-out oil filler cap. While replacing your oil filler cap can offer a temporary fix for this issue, you might want to check for any faulty engine components, such as a blown head gasket, that might be causing moisture to enter your engine oil tank.
Other troubleshooting tips
Any odd-looking substance buildup on the underside of your oil filler cap is not a good sign, and if the buildup is dark-colored, you need to take your vehicle to a professional for better diagnosis. A quick visual inspection on the oil filler cap will also tell you if the component is too worse for wear. If you notice any cracks, holes, or other deformations on the oil filler cap, then it's definitely time for you to get a replacement.