Blow by gasses

[nxk2000]

I have a 1991 4cyl 2.2 that to me has to much blow by. It’s like a fan blowing out of the oil fill when I remove the cap. If I take the cap and just place it over the hole it will bounce around from the air flow. Is this something normal with Hondas or am I looking at a rebuild?

[jeffcoslacker]

Pretty normal on small engines. You get a lot of pumping of crankcase airmass due to piston movement and relatively small crankcase volume.

If you put the palm of your hand over it, you'd probably notice pulses of suction as well. between the two, there is no net loss. With the cap in place and the system closed, the pcv system deals with any net blow-by.

If you take the oil cap off a lawn mower, for example, it'll shoot oil 6 ft high when you start it (don't ask how I know). That's not blow-by. It's cylinder pumping. Motorcycles are the same way...the smaller the case, the less empty space for air to be "sloshing" around in. So you feel it if you open it up.

Unless you are blowing a lot of oil spray into the intake through the breather side of the pcv system, I wouldn't worry about it.