Tom kite 3 #1 Posted June 11, 2017 J u st got 520h with a onanp220 motor And it's blowing oil out in where airbox. What's happen is it the head gasket blow. Share this post Link to post Share on other sites
boomers_influence 106 #2 Posted June 11, 2017 tom if i understand you correctly, you are saying you have oil inside the air cleaner housing. this WOULD NOT, be from a blown head gasket. it most likely be from EXCESSIVE crankcase pressure, it is time to do a compression and leak down test. boomers_influence@yahoo.com 651 437 2826 M-F 10-7 S-S 12-6 cent time. thank you. boomer ( the used onan engine parts guy, also NOS and new ) Share this post Link to post Share on other sites
ericj 1,576 #3 Posted June 11, 2017 2 hours ago, boomers_influence said: tom if i understand you correctly, you are saying you have oil inside the air cleaner housing. this WOULD NOT, be from a blown head gasket. it most likely be from EXCESSIVE crankcase pressure, it is time to do a compression and leak down test. boomers_influence@yahoo.com 651 437 2826 M-F 10-7 S-S 12-6 cent time. thank you. boomer ( the used onan engine parts guy, also NOS and new ) also check to make sure the dip stick cap is on tight, but it sounds like a clogged or stuck ball in the breather if not the check compression or do all of the above eric j Share this post Link to post Share on other sites
BESTDOGEVER 218 #4 Posted June 11, 2017 Check the drain hole in the valve sump as well as the pressure relief ball and spring getting to the relief is kind of a pain but is probably the culprit. 1 Share this post Link to post Share on other sites
