How to find oil leak in mercruiser 3.0?

[DPForumDog]

We have a mercruiser 3.0 that has an oil leak. A few weeks ago and we just used it for the first time since last year and it was dry. We filled it with oil that day and this weekend the dip stick wouldnt register. Paw said it is leaking all the way down in the oil pan. Maybe a bad gasket or plug. (Paw says there is no plug) or rusted pan but how would something filled with oil rust?

How do we find the leak without pulling the engine?

It's not from wear or overuse because we only drive it 5 times a year for about an hour at the most. We were even thinking the most economical thing to do is just add a couple quarts everytime we get use it. But we would need to determine how fast it was leaking. but of course I would rather fix the leak without pulling the engine. I

Any ideas shared would be appreciated.

Thanks
Granny DP
DPForumDog.

Our boat has a 2002 Fisher 22 ft pontoon boat with a mercruiser 3.0 Inboard motor

 

[nola mike]

Only way to find the leak is to visualize it. Probably need to clean everything first. Use a camera/phone to see inaccessible areas. The pan could rust from the outside, but I don't think that's common, especially if you're not in salt. More likely the pan gasket, timing cover, crank seals. There is a drain plug as well. If you run it without oil, you'll probably be able to find the leak when you have to replace the engine.

 

[tank1949]

Condensation or sweating from rain, spray, etc will gradually eat through sheet metal pans. There can't be but just a few things wrong. Take
Nola's advice!

 

[Scott06]

Check the timing cover on front of the engine. There is a section behind the balancer/pulley that I think due tot he balancer ebing there doesnt get good paint coverage at the factory and can corrode. You or someone will need to get in there with a light and a mirror

 

[Rick Stephens]

The bilge is filling with oil? Or is it just disappearing?

If it is filling the bilge up you need to spray it down with solvent and wash it out, then soapy water wash down. Get everything clean. Next, run it on muffs and use the video camera on a phone to eyeball around and see if you can find the leak.

 

[Scott Danforth]

rusted pan but how would something filled with oil rust?

rust doesnt care what is on the other side of the piece of metal it is eating. rusted oil pans are common in marine motors, and rusted timing covers are really common on 3.0 motors

How do we find the leak without pulling the engine?

you still have to pull the motor to fix the issue

 

[Bondo]

or rusted pan but how would something filled with oil rust?

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