3.0 Merc - Leaking oil in the bilge

[SWFLTom]

I took the boat out last night and putted around the river so I could get it up to temp and adjust the idle speed. While I was adjusting, I noticed some oil in the bilge. After looking around a bit I found the source. Right under the main crank pully. I suspect either the front main seal or the oil pan gasket. <br /><br />A friend suggested that this could be due to loose oil pan bolts. He also advised me to check the pcv. I pulled my flame arrestor to clean it and began investigating the pcv. I found that this engine seems to only have a breather elbow and tube going to the arrestor. Should I have a pcv?<br /><br />The leak dosen't seem to be all that bad. When I got home and checked the level, it was just below full. Maybe I can toss a bilge mat or bilge sock in there and keep a few qts with me?<br /><br />Many thanks!<br /><br />Tom

 

[Bondo]

Re: 3.0 Merc - Leaking oil in the bilge

I Think You've Already got it Figured Out Tom........<br /><br />No,... No PVC...... It's Just a Vent........

 

[jeff13601]

Re: 3.0 Merc - Leaking oil in the bilge

If you think you know where the leak is, fix it. Its only going to get worse

 

[Don S]

Re: 3.0 Merc - Leaking oil in the bilge

If there is a lot of rust on the oil pan and timing chain cover, you probably have a pin hole that has rusted all the way through. If that is the case there are more to come, and it won't take long.

 

[FENIXX3435]

Re: 3.0 Merc - Leaking oil in the bilge

Had oil in my bilge, Thought it was the pan? Turns out It came from a cracked spacer behind the fuel pump! easy job, lots to clean. Good luck!

 

[SWFLTom]

Re: 3.0 Merc - Leaking oil in the bilge

Ok...so I tightend all the oil pan bolts, cleaned the bilge, and changed the oil. Ran the boat for a bit and the leak is still there.<br /><br />There is no rust on the pan nor on the timing chain cover.<br /><br />The only place I see oil is on the front part of the pan and on the bottom of the lower pully.<br /><br />I think I'm over my head here...may just end up taking it to the local mercruiser stealership.<br /><br />Any comments?

 

[Fishermark]

Re: 3.0 Merc - Leaking oil in the bilge

Any comments?

Yep. Welcome to the forum from a fellow boater from Pt Charlotte! <br /><br />If the leak is truly minor I would simply keep an eye on it. Given what you have posted I suspect it is coming from the front main seal.<br /><br />You can clean up the engine and I've read where you can sprinkle some talcum powder on the clean engine, then it is easier to trace the leak back to the source. (Having said that, I've never actually tried it, so if you do, let me know if it works! )

 

[SWFLTom]

Re: 3.0 Merc - Leaking oil in the bilge

Fisher,<br /><br />Actually...I'm pretty convinced that it's the timing cover now. Seems pretty common on this boat.<br /><br />Where at in Port Charlotte are ya?<br /><br />Feel free to shoot me an email: swfltom at iburn.com

 

[Fishermark]

Re: 3.0 Merc - Leaking oil in the bilge

You've got mail!

 

[ALAG3]

Re: 3.0 Merc - Leaking oil in the bilge

SWFLTom,<br /> I just discovered this identical problem on my mercruiser, with an oil drip from the front of the engine...let me know if you figure out what exactly is leaking and I'll do the same if I figure it out! Thanks!

 

[Joenic]

Re: 3.0 Merc - Leaking oil in the bilge

Any of you guys figure out where your leak is?<br /><br />I have a 1999 3.0L Merc that seems to be leaking at the front of the motor. The timing cover seems very rusted.<br /><br />Hey Don, can the timing cover be changed without pulling the engine?<br /><br />TIA