Oil leak?

[Lady Hawke]

I have an Atomic 4 in a Pearson Triton. The oil seems to have leaked into the bilge, creating a smelly mess. My concern is finding the leak. My logic tells me the leak would be at the prop shaft but there is no evidence of a leak there. Where else could it be leaking?

[CalebD]

Welcome

Welcome to the Moyer forum on the Atomic 4.

If oil is not leaking out by the shaft it could be leaking out through the raw water pump which has both an oil seal and a water seal.

I'll suggest getting a few of those white oil absorbent pads which are approximately 12" x 20" at your local NAPA or other auto supply store. They should be placed strategically underneath the engine in the likely spots for leaks. While you are there buy a quart or two of cheap oil and put that in the engine with the white pads in place. With any luck you should be able to isolate where the oil is escaping the engine.

Others will be along soon with more good advice.

[BunnyPlanet169]

First: Welcome to the Forum!

Second: If you don't have it already, please consider getting the MMI manual from our sponsor. Don't walk, run. It's very, very good.

How much oil are we talking about? A lot, or just a bath tub ring? Noticable during use and oil monitoring, or just a messy accumulation over time? Always, or just recent?

Run a white napkin around the engine and engine spaces - it should be generally dry, but any leaks will leave a lot of oil to be found. It's either dripping straight down into the bilge, or oozing film along the side of the engine.

Some likely places, in semi order...

• Rear shaft seal - characterized by a spin art pattern of oil in the engine spaces.

• Rear cover outer seal - the outer edge of the same part

• Seal between the engine block and oil pan - in the rear it's always wet n the inside.

• There is a drain plug on the lower left side of newer blocks - I don't know how far back they go in time - it's almost always hidden and useless because of engine mounting

• The flywheel bell housing gasket between the flywheel housing and the block

• It's possible for the pan itself to rust through from the outside

• The valve lifter cover - usually just a stamped piece of steel and two small screws

• the oil gallery plugs used for oil pressure sensors - two on newer blocks, usually only one used

• Around the accessory drive and water pump - both sides are wet inside when running

Good luck - you've come to the right place!

P.S. Pictures?

[JOHN COOKSON]

Lady H
Welcome to the forum.
Another thought for you: Oil can leak outside of the engine, run down along the side of the engine and appear to be coming from a leaking rear shaft seal as it is spun off the rotating shaft/coupler.
Does the engine drip oil when it isn't running, much like a car in a garage, or is the leak more evident when the engine is running? If oil is dripping out of the engine you should be able to find where the leak is by putting a paper towel(s) under the engine as suggested in post #2.
If the leak appears to be coming from the raw water pump\accessory drive mounting try tightening the bolts that hold the pump to the accessory drive.
An oil adsorb pad will adsorb almost all of the oil in the bilge and maybe get rid of some of the oder. If there is any way possible keep a oil adsorb pad between the engine and the bilge to keep as much oil out of the bilge as possible until you get this figured out.

TRUE GRIT