Signs and Symptoms of a Faulty Saab 900 Oil Filler Cap
Your Saab 900 oil filler cap keeps your engine oil from getting contaminated and from leaking out of the engine oil tank. However, constant exposure to heat and extreme pressure can wear this component out and keep it from doing its job properly. Avoid the hassle of a faulty oil filler cap by taking note of these common problems:
Sludge under the oil filler cap
Differently colored deposits on the underside of the oil filler cap can point to several problems. The most common deposit, a white, creamy sludge, is caused by the mixture of water and engine oil. In some cases, water droplets can build up on the underside of your oil filler cap signaling that moisture is still entering your engine oil tank but has not yet mixed with your engine oil. On rare occasions, a brownish or tar-like substance can also accumulate beneath your oil filler cap due to a coolant leak. Most of these cases point to a worn-out, improperly fitted, or defective oil filler cap, but it would also be advisable to examine any related components that might be causing moisture to enter your oil filler cap.
Cracked or loose oil filler cap
If you notice puddles or drops of engine oil on and around your oil filler cap, then you probably have a cracked or loosely fitted oil filler cap. This problem can cause your engine oil to spill out of its tank resulting in low engine oil level and eventual overheating of your engine. Inspect your oil filler cap carefully and see if it is cracked or if you can't tighten it properly anymore; these cases will definitely call for an oil filler cap replacement.
Other common oil filler cap issues
Sometimes, your oil filler cap might seem clean with no signs of an engine oil leak around it, but you will notice some air or smoke spitting from your oil filler cap. This can also be caused by an improperly fitted oil filler cap, or in some cases, a worn-out O-ring. A visual inspection can easily tell you if the O-ring in your engine oil tank is too worn out to function properly. When looking for a replacement, remember to choose a good heat-resistant O-ring.