Mercruiser 5.7 question - Maxum Boat Owners Club

forbes210 · 12-04-2013, 03:17 AM

Hi All,

Before I'll move to the subject I wanted to say a bit more about my boating experience. Its my first season (NYC) since I bought 2002 Maxum 2500 SCR with 5.7 Mercruiser. Had a lot to learn during this summer but I definitely enjoyed the boat (did 80 hours). Recently took the boat out of the water and I'm trying to address couple issues.

Right at the end of the season I've noticed some oil in bilge area. It looks like engine oil. Today I squeezed in engine compartment to have a peak under the engine trying to locate possible leak. I'm not sure but oil might be leaking from hose attached to the oil pan which runs to the top of the engine and is attached with wire clamp. I was able to remove the the hose from the oil pan and oil purred into bilge area so I put it back in immediately. I've noticed small rubber ring on the hose plug and entire hose felt loose. My question is if it's possible that the leak came from there? Also I'm curious whats the purpose of this hose? Thanks in advance.

forbes210 · 12-04-2013, 03:41 AM

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Jerryh3 · 12-04-2013, 10:32 AM

Yes, it's very possible that's where the leak is coming from. That hose allows you drain the oil without having to access the drain pan bolt which is pretty much impossible in some boats. Origanally that hose was connected to the bilge drain plug with a clip. The idea was to remove the bilge drain plug, pull the hose through the hole, and drain the oil. I have it on my boat but don't use it. I siphon the oil through the dipstick using this.
http://www.westmarine.com/webapp/wcs...classNum=50402

jrsick · 12-04-2013, 12:09 PM

Yep, that hose is to drain engine oil, just loosen the brass nut on the end. You may need to tighten the nut to stop the leak.
I use that hose when changing oil. I like it because you can pull the hose clear of the bilge and drain the oil into a jug from outside the boat. I also use it as a mid-season check for water or debris in the oil. Drain about a half quart into a clear water bottle to check the condition of the oil.

mmwjr · 12-04-2013, 12:59 PM

forbes welcome aboard.

As Jerryh3 and jr have stated it's the engine drain hose. The end you are showing should be connected to the bildge drain plug so when you remove the plug it alows you to pull the hose out the drain hole. Then as jr says remove the plug on the hose to drain engine oil into a container.

Now to you question it is possible the leak is where the hose attaches to the oil pan. There are 2 possible areas where this could happen. First is the interface between the oil pan and adapter block (accept the hose and has the correct thread size for the oil pan), this should have a flat plastic washer just like the oil drain plug on a car. Second is the o-ring on the hose that tehn threads into the adapter block.

Other common sources of oil leaks are the front and rear main seals. The front can be replaced with the engine in the boat but the rear requires pulling the engine.

Good Luck and let us know what you find or if you have any further questions.

ss3964spd · 12-04-2013, 07:17 PM

Unfortunately the oill pan itself can also be a source of a leak. The pan is stamped sheet metal and can develop small, pin hole, leaks from moisture.

If you can do so get some rags and cleaner - like 409, and wipe down the bottom of the oil pan. Then after a week or two check it again. If you get oil on the rag the second time it may mean a pan leak.

forbes210 · 12-04-2013, 08:58 PM

Thank you for all the responses.

I actually bought exactly the same unit as Jerryh3 to perform my first oil change. It worked well.

It looks that the most possible reason is o-ring on the hose getting into the adapter on oil pan. When I played with this connection it felt very loose and there was an oil droop on the hose which could just get on it from bilge water. Do you know by any chance where I could get the replacement o-ring? Is it got to be anything special because of the temperature or could be ordinary o-ring which will fit the size. Now when the boat is on shore is probably the best time to test it out since I can keep bilge completely dry and place some rugs or paper to localize the leak. the only think that boat standing still on blocks might not produce any leak but thats just a slight chance.

mmwjr · 12-04-2013, 10:37 PM

Nothing special about the o-ring. Home Depot, Lowes, Marine parts store. You can get an oil pad to place under the engine, it will suck up any leak/spill.

Yep fix it on land is best but you will need to drain the pan otherwise 5 qts is alot to hold back when you remove the hose and try and replace the o-ring. You'll just end up with a big mess.

forbes210 · 12-05-2013, 03:12 AM

Thank you mmwjr. Maybe I'll try to plug the oil pan somehow to replace the o-ring or will wait till spring and do that during oil change.

CGG · 12-06-2013, 11:53 PM

Can also be the drive oil. Good idea to have the out drives pulled and checked out.

mmwjr · 12-07-2013, 12:34 AM

Yep could be gear lube from the remote fill/montor but pulling the drives won't tell you if this is the source. Since he can feel oil on the bottom of the engine I would be pretty sure it engine oil. With that said I do agree the drive should be pulled to lube the u-joints, replace drive to bellhousing seals, inspect bellows, and check engine alignment. This is part of maintance and sincethe boat is new to him no telling when it was last done. Of course all maintaince should be performed.

i.e. change drive lube, engine oil, check power steering fluid and lube cable, ...

forbes210 · 12-09-2013, 11:22 PM

After doing boat yoga entire saturday I discovered that the leak comes from power steering. Was difficult to tell the different in color between engine oil but its definitely power steering fluid. I'm planning to have a closer look next weekend after removing risers.

mmwjr · 12-10-2013, 02:03 AM

Can you tell where the leak is? PS pump, hoses, PS cooler, PS assist rack at transom are all the places to look.

forbes210 · 12-10-2013, 03:18 AM

I'll work on inspecting the leak this saturday and will keep you posted. Thank you!

forbes210 · 02-28-2014, 11:20 PM

Finally I was able to get a chance to work on my boat and inspect the leak. The reason was very simple: stripped hose clam on one of the hoses connecting to cooling steering tube. I guess past mechanic stripped the clamp and didnt bother to replace it. Heres an image showing the place where the hose with defective clamp was connected. I couldn't locate it in the first place since its located behind the engine. Got a better view after removing manifolds and risers. Also to test the system i connected cordless drill to the power steering pump to get pressure without running engine.