Mercruiser 3.0 oil leak

[Merc3.0]

Hi, just paid $1100 to stop rear main seal oil leak but continues at upper engine on dipstick side. What could it be? Recent valve job, manifold/risers.

 

[alldodge]

Hi, just paid $1100 to stop rear main seal oil leak but continues at upper engine on dipstick side. What could it be? Recent valve job, manifold/risers.

Howdy and :welcome: to iboats

From this short post I would say your being taken advantage of. You had a rear main oil leak and probably also had a dip stick leak along with a PVC of breather tube leak. In my opinion you have worn rings and a lot of blow-by. The only way to fix blow-by and worn rings is to rebuild the engine.

Do you have any other info other then what you just mentioned?

 

[Merc3.0]

Hi, thanks for the quick reply, 2005 bayliner 175 mercuiser 3.0 TKS, valve job due to stuck pin, risers/manifolds wouldn't seal anymore due to corrosion so new ones, solution to leak was supposed to be rear main seal job. Yesterday at first outing, engine died at dock, zero oil pressure gauge, called mechanic, he told to restart push lever forward and the oil pressure rose and I used it for 35 minutes. At cleaning today, no oil pressure, I started anyway and quickly put it in gear, after 12 minutes to warm up engine, back to idle and a few seconds died, back to zero oil pressure. Opened cover, saw oil at bottom coming from the dipstick side from upper part of engine as before. Taking it tomorrow morning to mechanic but I'm new to this and I need pointers, again thanks.

 

[biggjimm]

Could be either the valve cover or lifter/pushrod cover leaking. Both of which should have been replaced if you had the head serviced.

If you have zero pressure at idle & it comes up with some rpm's, you're probably pretty low on oil or the oil pump is shot. Probably low on oil since you have a leak but I definitely wouldn't run the boat until you get that zero pressure at idle resolved.

 

[Grub54891]

You need a new mechanic. One that know's how to diagnose it properly.

 

[alldodge]

Hi, thanks for the quick reply, 2005 bayliner 175 mercuiser 3.0 TKS, valve job due to stuck pin, risers/manifolds wouldn't seal anymore due to corrosion so new ones, solution to leak was supposed to be rear main seal job. Yesterday at first outing, engine died at dock, zero oil pressure gauge, called mechanic, he told to restart push lever forward and the oil pressure rose and I used it for 35 minutes. At cleaning today, no oil pressure, I started anyway and quickly put it in gear, after 12 minutes to warm up engine, back to idle and a few seconds died, back to zero oil pressure. Opened cover, saw oil at bottom coming from the dipstick side from upper part of engine as before. Taking it tomorrow morning to mechanic but I'm new to this and I need pointers, again thanks.

Agree you need a new mechanic, but you might be stuck with current one in this repair. If it's coming from the valve cover then its not blow-by. If you didn't have zero oil pressure before you shouldn't have it now. Running the engine rpm's high to show oil pressure is a bad way to go. The engine is dying because the oil pressure drops and then the fuel pump stops.

Did you have low oil pressure before? Being a 2005 I'll guess its a fuel injected engine.

 

[Merc3.0]

It's a carburator.

 

[alldodge]

It's a carburator.

Ok, but did you have an issue with low oil pressure before?

 

[RaceCarRich]

"At cleaning today, no oil pressure, I started anyway and quickly put it in gear, after 12 minutes to warm up engine, back to idle and a few seconds died, back to zero oil pressure."




This may be obvious but want to make sure.... You realize that before starting and after stalling, oil pressure should read 0. Oil pressure only exists when engine is running.

Also, if you got multiple leaks, blowby is a fair possibility.