Logo
FULL SITE MENU

Johnson 4 stroke with high crank case pressure

D

dkrahl

New member
"I have a late '90's J

"I have a late '90's Johnson 15 HP four-stroke that leaks oil around the dipstick. The dipstick is plastic with a rubber seal. It doesn't have an extremely tight seal, but tight enough that the stick doesn't blow out of the motor. If the motor is running, and I pull the dipstick out, there is quit a bit pulsating pressure coming from the bottom end / crank case. I would like to know if this is normal. If not, where is the vent usually located and what does it look like? Thanks, Dave"
 
"Thanks for the responses. The

"Thanks for the responses. The oil is not too full. As far as removing the dipstick while it was running, I was trying to see if there was enough pressure to potentially blow the dipstick out while in operation. It seems that the pressure is high enough to possibly blow it out if the problem gets worse. The pressure is causing the oil to seep out around the dipstick seal and it's blowing all over the place, making a mess that eventually end up in the water when I'm out on the lake. The rubber plug-type seal seem a little week. I may just try a new dipstick. I was just wondering if there is a crankcase vent that may be clogged or have a filer that isn't working properly.thanks again, Dave"
 
I think you will find that the

I think you will find that there is a breather hose from the cylinder head cover to the air horn. Check that is not blocked esp the end connections
 
"be leary of cheaper aftermark

"be leary of cheaper aftermarket oil filters
some have check valves in them,
had an experence with a john deere oil press
shot up well past normal psi ,could not figure out why
until dealer rep came to shop,"
 
Back
Top