OIl leak port engine 1986 30' Weekender

[Equinox 2]

I have developed a serious oil leak somewhere low on the Port engine. It is a 260 HP
MerCruiser, 350 Chevy block. My mechanic believes that it is either a rear main seal
or oil pan. Either will mean pulling the engine out at the end of the season. Anyone have a similar experience or words of wisdom?

Thanks!

 

[Getaway]

If it's a rear main, it will leak when the motor is running back by the starter. Fire the motor up and get your head or a mirror down there and watch it at idle. If the oil starts to pool at the back of the block near the starter, chances are it's a rear main.

Like you said, either way the motor has to come out and you will be replacing both anyways.

 

[dwna1a]

Before you get that far and if you have a remote oil filter, check to see if the o ring has gone bad at the location where the filter would have mounted on the lower spot.

 

[dvx216]

My 5.7 got a hole in the mechanical fuel pump above the diaphragm it puked out two quarts of oil but it would not leak when the boat was sitting still.It was hard to find and low on the motor.

 

[julietbravomike]

I once had a leak develop at the oil sender - the unit itself was leaking. And +1 on the remote oil filter o-ring for the blockoff plate where the oil filter would originally mount - those plates can also just get loose over time and need to be tightened. My advice is to get the engine and bilge area under the engine as clean as possible then run the engine and diagnose the leak. Especially before you spend a bunch of money. Lay down white paper towels to help spot the drips. Good luck!

 

[JVM225]

Try some dye in the oil before you pull it. It will make tracing the leak a little easier.

 

[SCORPIO]

An inspection camera is a great tool to have to look under and behind the engines. I would verify the source of the leak before committing to pulling the engine. You may find something that can be rectified with the engine in situ.

 

[andyr]

Look at where the bottom of the oil dipstick tube attaches to the engine.