2005 Volvo vnl630 Air filter blowing air out.

There shouldn't be any air coming out of the filter..
A little more info would be helpful.. make and model of motor .. etc etc

 

I’d suspect a valve problem. Perhaps send it in for a valve set. They may find something out of sync there. Maybe a burnt or broken valve

 

Is it running backwards?

 

People laugh, but I have had that happen.

 

I have seen many Detroit 2 strokes do this with a heavy load and someone who is jumpy on the clutch starting it off.
Sucks air down the stack and blows smoke out the air cleaner.

 

I’ve done it twice, bumping a dock too hard. Little 238 2 stroke. Runs a little rough reverse becomes forward. First time took a minute to figure it out. Lol. Shut it off, crank it up. Good as new.