KX161-3 Pressure From Oil Fill Cap

I have been looking at a 2006 KX161-3 with 2050 hours on it. When I removed the oil fill cap, you could feel air coming out of the filler hole. There was no smoke visible. The machine is at a dealer and they had two other KX161s of similar age and hours. The other two machines were the same - you could feel air coming out of the oil filler hole.



I have read that this can be a symptom of blow by. None of my other diesel engines do this. Since the three machines were exactly the same, would it be reasonable to consider this normal for this engine?



Thanks. Any input would be appreciated!

KX161-3 Pressure From Oil Fill Cap