Leaking motor oil, source?

[customfab]

More fun for me. Pulled the boat out of the water on Sat and noticed some motor oil on the plug. Went to the back and touched my hand under the motor and found quite a bit of oil sitting under it. The engine (2001 2300V w 350 MAG MPI)ended up being about 1-2 quarts low on oil. It hadn't impacted the oil pressure at that point nor did the boat get hot so luckily I caught it quickly.

Any thoughts on where to check for leak source?

I know worse case could be a cracked block but right now that makes no sense. I also know it is coming from the engine specifically vs V-drive.

Need input on more "normal" sources of a leak from the engine?

Thanks

[da.bell]

Have you checked the color of your oil? Does it look like the color of chocolate milk?

[raythompson]

Check around the oil filter and the oil drain plug. Then check the front and rear seals on the engine. Those are the most commmon points of oil leaks.

[dogbert]

On most boats, there's an oil pan drain hose that's usually clipped onto the engine in a high location. They use this hose to change the oil by routing it through the drain plug. It's possible this hose fell down into your bilge and is leaking.

[customfab]

Thanks guys, I'll check all those locations. I don't believe the 2300V came with an oil drain hose.

Oil is certainly not milky. Good looking synthetic oil. Problem is, some of it isn't sitting in the pan!

I've also read up about the intercooler leaking?

[bobbysky]

I just had the same problem with my boat, exactly. It ended up being a pinhole rust spot in the oil pan from the previous owner letting water sit in the bilge for an extended period of time. I had to pull the motor to get the oil pan out and replaced. Hopefully it's not that, because it's kind of a pain, but at least I got to learn a ton about my engine.

Check the remote oil filter, where it runs into the block, and all those connections. Check and see if your leaking from the valve covers or oil pan gasket. Other then that it would have to be a rear or front main seal, most likely not.

Hope it's just the gasket on the oil drain plug.

[chpthril]

Common leaks:

Oil pressure sending unit, valve cover gasket, intake manifold end seals, distributor seal, double gasket on oil filter (old one stuck during last service)

[dogbert]

I've also read up about the intercooler leaking?

There is no intercooler. There is a fuel cooler, but it wouldn't have oil in it. You should have an oil pan drain hose...all Mercs came with it.

[customfab]

There is no intercooler. There is a fuel cooler, but it wouldn't have oil in it. You should have an oil pan drain hose...all Mercs came with it.

Thanks for the correction. I will take all the advice and start the wild goose chase this weekend!

[dogbert]

Thanks for the correction. I will take all the advice and start the wild goose chase this weekend!

I'll try and take a picture of mine this weekend (if I can remember).

[customfab]

So guys, I believe the oil leak is coming from the most ideal spot for a oil leak in my opinion.....the oil drain tube.

However, there is virtually no room to remove the banjo bolt which allows you to replace the drain tube.

Has anyone had to remove the banjo bolt? Must you pull the motor? Ahhhhhhhh.

[customfab]

So guys, I believe the oil leak is coming from the most ideal spot for a oil leak in my opinion.....the oil drain tube.

However, there is virtually no room to remove the banjo bolt which allows you to replace the drain tube.

Has anyone had to remove the banjo bolt? Must you pull the motor? Ahhhhhhhh.

Just to everyone know. I was able to remove the banjo bolt with the very little clearance. You can also get it back with some patience.

I thought that fixed the problem but no luck. Boat is still leaking oil at about 1/2 - 1 quart per 2 hours of use. I just keep it topped off as I'm too tired of fixing minor crap. Probably wait till end of season.