compressed gas emits from engine sump

[Gaminis]

I have a belta 1300cc vehicle since 2011 upto now under me & as I remember while running when opened oil filling cup and dip stick compressed gas escape since earlier but oil level same until next 5000km service please explain me the reason & remedy 

Thanks 

 

[Rumesh88]

Welcome to the forum. If you notice compressed oil fumes in the engine first step is to remove, test and clean the PCV valve or if the PCV is really stuck to replace it. As a quick test start the engine, open the oil filling cap, place the  cap upside down on the filler hole and observe how the cap moves up and down. If your PCV is stuck the cap would be thrown off. The idea behind the test is that normally you should have a "net" negative pressure inside the crankcase. In some cases oil baffles inside the valve cover could be clogged up too but first attend to the PCV and see if it makes a difference.