blefever

Saturday I was getting my boat ready for the 1st trip. My starboard motor, 7.4 ltr, running on the hose was leaking a little bit of water at the back of the motor and bringing down a little oil with it. Very hard to see back there but best I could tell with a flashlight and mirror was that the water was running down the transom from the outdrive mount. The only thing I can think is that the raw water hose through the drive is the source. The exhust is through the transom so no water in the y-pipes. Is there any other water lines coming through the drive? Any thoughts?

As far as the oil, I'm thinking it is coming from the back of the motor and being washed down with the water (it is one stream of oil and water) but as I said, very hard to see back there. What I can see looks fine. Again, any thoughts, and please don't say "rear main" lol, not looking forward to pulling a motor.

It's not a lot oil or water, but I sure hate oil in the bilge.

PatriYacht

Leaks are always a pain to find. Check the boot on the outdrive. Very common to have leaks there. As far as the oil, check for valve cover leaks. It runs to the back of the engine because of the angle the boat sits at. Rear main is unlikely unless the engine has a lot of hours.

mike tkach

is this the first time starting since winterizing,i hope you don,t have cracked manifolds or block.

blefever

Thanks for the ideas. No cracked block or manifolds. Everything I can see and get to looks fine. We did go to Catalina last weekend, and it really did not get much water in the bildge, and the bildge pads did soak up the small amount of oil. It's just that I like things perfect, so this bugs me. I'll keep looking.

Zackman

Not sure what drive or who the manufacturer is, since you don't state in your post. Assuming it's a Mercruiser with a Bravo drive.

If it is indeed a water and oil mixture and comming from the rear of the motor, could it be from the power steering lube oil cooler? Have you been losing any power steering fluid?

blefever

Yes, it's a Mercruiser with Brovo 1. No loss of power steering fluid or outdrive oil. The motors do use some oil, but I'd say normal use for motors with 300 hrs.

It seems to be coming from right where the drive comes through the transom and running down the transom, not so much the back of the motor. I can see water running down the transom and as it runs into the bilge it has some oil with it. Not sure if the water is just picking up oil from somwhere else or if both are coming from the same place. The water goes behind a stringer where I can't see, before it runs into the bilge where I can see, so it may be picking up the oil from there. Could be oil from an old leak that is just now getting washed down from a new water leak.

If only I could be about the size of Barbie for a day, I think I could find the source or sources.

mrquad1

sounds like you may have the seal next to your gimbal bearing going out.when they leak water enters in the area you described and the oil is actually from the grease in the gimbal brgs.you must pull outdrive to replace,not a major job but does take a few hours.

blefever

Mrquad1; I first noticed this as I was running on the hose in the driveway. Could what you are saying happen when the boat is not in the water? Running on the hose, I thought the only water coming through the drive would be in the raw water suction hose?

Zackman

Not to answer for Mrquad1, but no. Water enters through the water hose at the gimbal housing. There is a housing that interfaces the inlet water hose to the raw water pickup on the gimbal housing. You should be able to see the hose connection from the port side of the engine.

Is it leaking from there?

From the raw water pump the water travels to the power steering oil cooler on the back top of the engine. From there it goes through the fuel cooler, if you have fuel injection. I believe on some 7.4 there was a oil cooler, but I've never owned one so I don't know for sure.

I hate to mention this, but could it be comming from the engine such as a core plug?

blefever

The water is for sure coming from the drive transom mount area not the motor. The motors have a closed cooling system and this is water, not green antifreeze. I'v checked all the raw water lines and coolers as best I can.

I think now, I'll pull the engine hatch off so I can lean over the back and get a better look into the drive mount. The motor needs to be running to get the water leak, and it's hard to lay on the motor and look around when it's running.

Thanks again to all for the help.