1GM10 pushing oil out

[fastjedi]

1GM10 ... 2001 ... 230 hrs
Twice this year a faint smell of hot oil has encouraged me to take a look in the engine bay. After > 1hr of running at moderate (1/2) throttle it has shot oil up the left hand side of the motor. I'm not sure where it has come from. Logically, it would have come from the dip stick hole, but I am carefull to replace the dip stick properly and don't beleive I have found it ejected (although I could have overlooked this in my panic).

Thing is ... it's taking all the enjoyment out of this years boating .. and I'm reluctant to get a marine engineer involved because there is nothing to see. The w/s manual says there is a crankcase pressure reed valve in the valve cover. I am considering taking a look. Has anyone experienced similar?

 

[fireball]

If you think it might be comming out of the dipstick hole then pack some paper towelling around it and then run for a while - keep an eye on it, you don't want it too hot!!
If it is comming out from there then it should be obvious.

Other than that - get the yanmar GM workshop manual and have a look ... not sure where else it could be off the top of my head

 

[ShipsWoofy]

Have a good feel around the two lower oil pipes which run under the flywheel, notorious for corroding and then splitting.

 

[AndCur]

Hi

If oil is getting pushed out past the dip stick this is more than likely caused by a build up of crankcase pressure. This could be caused by a couple of things.

1. Poor seal at the dip stick.
2. To much oil in the engine.
3. Blocked breather pipe/system
4. Worst case and probably very unlikely worn rings/bore.

Hope this is of some help.

Andrew

 

[Nauti Fox]

If it is coming up past the dipstick it is probably the breather, do check it soon as the next thing to go could be the crankshaft seals making it a whole lot worse!

 

[charles_reed]

1. Check the breather pipe, from rockerbox to inlet manifold is clear and fully connected.
2. If that doesn't stop the problem, take off the rockerbox and clean the valve into the breather pipe (I use petrol)

That breather actually reduces the pressure in the crankcase very considerably and needs to be tight on all its spigots with no leaks at all.