Is it normal to have engine oil in the crankcase vent tube?

[DelEverly]

If it's a slight amount of engine oil, it is a normal phenomenon because the crankcase vent tube will have slight oil vapor entering. However, if there is a large amount of engine oil, it is abnormal and indicates that the turbocharger has an oil burning issue. Reasons for having engine oil: There are many reasons that can cause engine oil in the intake pipe, including driving conditions, maintenance, normal crankcase ventilation, etc. This is determined by the characteristics of the turbocharger and the layout of related systems. Prolonged engine idling, clogged or deformed crankcase ventilation system, and coking of lubricating oil in the turbocharger's intermediate housing can also lead to this issue. Effects of excessive engine oil: If the engine oil is overfilled, it will inevitably increase the lubricating oil content in the crankcase ventilation system, thereby promoting the entry of lubricating oil from the crankcase ventilation system into the intake pipe.

[SanWalker]

It's not uncommon to see a bit of oil in the crankcase ventilation tube. Back when I was younger and worked on cars, I came across this situation quite often. The PCV system is designed to let the oil vapors escape from the crankcase, so a little oil mist is normal and won't harm the car. However, you should pay attention to the amount—if oil is dripping out or accumulating at the tube opening, that's not right. Possible causes include worn piston rings, which allow oil to be sucked in, or a PCV valve that's been clogged for too long without replacement. I once had an old car like that—blue smoke from the engine and excessive oil consumption. After spending some money on repairs, it ran smoothly again. Generally, it's recommended to check the PCV valve and oil level during maintenance. Don't wait until the engine develops major issues to take action. A little attention in daily use can save a lot of hassle.

[DelThomas]

As a car enthusiast, I've done some research on the crankcase ventilation system, which is designed to manage engine pressure. Having some oil there isn't necessarily a big issue – a small amount of oil mist is normal, like when the engine is running and the oil-gas mixture carries some oil vapor out. But too much can be problematic, such as oil being drawn into the intake system, leading to poor combustion or blue smoke. The key is assessing the severity: it could be caused by a faulty PCV valve or piston blow-by, and checking is simple—just replace the PCV valve or test engine compression. Ignoring it can hurt performance and increase fuel consumption, so regular checks on this component can prevent issues. Over time, I've learned that addressing small issues promptly is much more cost-effective than dealing with major repairs later.

[MaxLee]

A small amount of oil in the ventilation tube is normal, as it's designed to retain some residue. However, monitor the quantity—if oil starts leaking out, it might indicate issues with the piston rings or overfilling. Ignoring it for too long can lead to clogged tubes affecting emissions or engine overheating. Checking isn't difficult; inspect the PCV valve or clean it during routine maintenance. Safety first—don't let minor issues escalate.