John Deere 425 Blowby

[a.palmer jr.]

I have a John Deere 425 tractor that's got a severe case of blow by. It blows the dipstick and the oil cap off of it. I was told to change the pvc valve behind the flywheel, which I did but I don't think that fixed the problem because the old valve, which looks like a reed valve, looks as good as the new one. I checked the compression and it showed about 170 on both cylinders but seems like the last time I checked it it was lower on the left side by a few pounds than the right. Is there anything else I should check while I have the engine out of the tractor?