Mercruiser 8.2. oil in exhaust

[joelger]

I just bought a 2011 searay 250slx with a mercruiser 8.2 sterndrive. Boat runs great. I have had it out a few times with no issues. I just noticed an oil stain on my driveway and noticed oil coming from the area of the drive shaft bellow at the transom. I checked my outdrive oil reservoir and found that the oil was fairly low. The amount of oil that had leaked was probably about 4-5oz. I dont see any oil in the bilge and although it is hard to tell it seems to be coming from the bottom of the bellow where it is attached to the transom.
Im trying to get an idea of what the problem might be and am i ok to just keep an eye on it for while until i have a chance to have it looked at (or do it myself).
My thought is the only place it is likely to be leaking from is the seal where the ujoint yoke goes into the upper out drive. Anyone disagree? Possibly the tube that runs from the reservoir to the outdrive?
Any thoughts?

 

[Scott Danforth]

find the leak. if oil is leaking out, water is leaking in.

potential leak spots that will get into the water stream and ultimately into the exhaust stream are Power Steering cooler and oil cooler

drive oil would not mix with the exhaust. however leak externally. maybe a prop shaft leak.

 

[joelger]

It does not appear to be in the exhaust. When the drive is up i can put my fingers in to the exhaust and it doesnt seem to be from there. It seems above the exhaust where bellow for the driveshaft is. If i drain a small amount of oil from the drive the oil looks clean, not cloudy at all.

 

[joelger]

additionally, the oil that is leaking is pure oil. Clean and not cloudy or mucky at all. Im wondering if the leak is when the outdrive is raised and the oil is sitting against the upper seal... If the leak was from when i was running the boat, it wouldnt be pure oil.

 

[Bondo]

additionally, the oil that is leaking is pure oil. Clean and not cloudy or mucky at all. Im wondering if the leak is when the outdrive is raised and the oil is sitting against the upper seal... If the leak was from when i was running the boat, it wouldnt be pure oil.

Ayuh,..... Welcome Aboard,...... If you check the drive oil from the bottom of the case, the next day,... 'n it is pure gear oil, you can refill it, 'n roll the dice to finish the season before it gets resealed,.....
If you find anything but clean good oil, it'll need to be fixed,....

 

[joelger]

Any thoughts on my theory of it being the upper seal near the ujoint.

 

[Bondo]

Any thoughts on my theory of it being the upper seal near the ujoint.

Ayuh,..... Could be, but how is the oil gettin' outa the inside of the drive bellows,..??
More likely the hose from the oil bottle on the motor,....

 

[joelger]

I like that answer. It is hard to see up inside the whole transom assembly and i need to find something that can show me exactly how the tube from the reservoir is routed. I think the first thing i need to do i check the drive oil from the bottom in the morning after it has been sitting for 12 hours. It hasnt been run in two days but the drive was up. I just put it down and ill check it in the morning.
Any idea where i can find something that will show me how the tube to the reservoir is routed?

 

[Bondo]

I like that answer. It is hard to see up inside the whole transom assembly and i need to find something that can show me exactly how the tube from the reservoir is routed. I think the first thing i need to do i check the drive oil from the bottom in the morning after it has been sitting for 12 hours. It hasnt been run in two days but the drive was up. I just put it down and ill check it in the morning.
Any idea where i can find something that will show me how the tube to the reservoir is routed?

Ayuh,..... One of the guys will probably post ya a screen shot,....

You can't fix it without pullin' the gimbal housin',....
If ya don't know when the bellows were swapped out last,.....
I'd just "Plan" on a full transom service, 'n swap out All the rubber parts,.....

 

[dubs283]

Any idea where i can find something that will show me how the tube to the reservoir is routed?

Tilt the drive all the way up and turn the steering hard to port

Lay under the bell housing and shine a light upwards. The external gear oil hose runs from the bell housing to the gimbal housing next to the shift cable bellows and u joint bellows (stbd side of bell housing). It's approx 1/2 inch o.d. diameter hose, 10 inches long. Check for oil residue there. That hose is prone to age cracking and leaking gear oil.

FYI, merc recommendeds using high performance gear oil in all sterndrives, it's a bluish/green color. If PO used seirra or gl5 equivalent it'll be gold in color

 

[QBhoy]

Hi. There is exhaust exits at the transom shield as well as the actual through hub exit. I’m perhaps thinking about asking if this is the first time it’s been ran since she was winterised ? More specifically thinking that if she was winterised as per the manual, with some 2 stroke oil mixed into the fuel. I do that before each winter. I literally just fired up my mpi boat for the first time this weekend…she blew 2 stroke oil out the side exits for a while. Could this be what’s happening?

 

[joelger]

i was able to see where the oil line from the reservoir comes through the transom to the outdrive. It is on the starboard side of the unit (although the reservoir is on the port side). I am able to see up in there with a flashlight and it appears that the oil spot begins there. It is above the driveshaft bellow and again, it is pure oil. Not a watery mix. I also found a diagram of the whole reservoir assembly that shows a nylon clamp where the hose attaches to the fitting. Go figure, mine has no clamp. I also noticed that the hose has some dry rot right at the end. Im figuring this is my problem.

When i bought the boat 3weeks and 4 hours of use ago, i drained some oil from the outdrive and it was clear as could be. I checked it this morning and although it was just as clear, there was a cloudy streak in it.
Im figuring that maybe a drop got in where clamp is missing and settled to the bottom. The area where the clamp is sits right at the waterline or a little below.

I figure i can probably get a clamp on the hose to get though the season and i will keep a very close eye on the oil level and drain a few drops each time i use it to be safe. Since i trailer it home each time i use it this should be easy enough.

Any additional comments? Im all ears (or eyes in this case)

JG

 

[dubs283]

The clamp isn't your issue. I quit putting clamps/wire ties on the gear oil hose years ago, never had an issue

The dry rot is most likely your issue. The hose will crack from dry rot fairly easily. It can be replaced without removing anything including the drive but it takes a steady hand and a sharp razor knife

 

[joelger]

As it turns out, the issue is that the plastic fitting that comes through the transom is cracked. When i turned the outdrive to one side to try and get a clamp on, i noticed that the hose was pulling on the fitting with some force and appeared to be bending it. I tugged a little on it and it was still attached was definitely bending the fitting and as i would tug on it, the oil would begin to increase in the volume that was leaking out. I eventually broke it off. Im sure it was just a matter of time before it broke off anyway. Better in my driveway than out on the water.

I'm wondering if i can just plug it off for the rest of the season and just keep checking the oil the conventional way and replace the hoses and fittings in September when i put the boat away for the winter. Replacing that fitting looks tricky as it exits the transom under the water intake and steering piston. I have fairly good access from the other side but it is somewhat tight. I just don't want to open a whole can of worms and lay the boat up. I could easily plug the line up at the reservoir and at the outdrive.
Thoughts?

 

[dubs283]

That fitting is a real chore to replace. It installs from the outside but there is a clip on the inside of the gimbal housing that needs to be removed first, along with the gear oil hose from the monitor.

Unfortunately you will lose most of the gear lube from the drive if you operate the boat with the hose/fitting disconnected. Thus will result in the upper gearset in the drive to fail, not good. The job can be done by a diyer, it's not fun even for a seasoned boat mechanic but it does need to be fixed before you use the boat again

 

[joelger]

Im not sure why i would lose all of the oil if the oil tube that leads in to the drive is plugged so that no oil can get out and no water can get in? I was thinking this would just then be the same as any drive that does not have the reservoir. I can check it manually.

 

[Bondo]

Im not sure why i would lose all of the oil if the oil tube that leads in to the drive is plugged so that no oil can get out and no water can get in? I was thinking this would just then be the same as any drive that does not have the reservoir. I can check it manually.

Ayuh,..... That hose is the dry-rotted one, so be extra specially conscious of that fact,.....

 

[joelger]

Quite honestly my concern about doing this now, whether it be me or a shop is that in order to do this would require removing the seawater inlet that is held in place just above this fitting on the transom. They look to be 1/4' steel bolts run into an aluminum part. This combination breaks quite easily and the would be a serious mess. Not the worst i have ever faced but it would likely have the boat OOS for the remainder of the season.

 

[joelger]

The hose doesn't look so bad other than where it was connected to the transom fitting. It actually seemed too short which would explain why it was tugging on the fitting causing to to crack. In any event i ordered all of the parts but am i correct that if i can plug this hose up that runs into the outdrive i should be able to use the boat and just check it conventionally? If the hose is plugged am i correct that i should not lose the oil?

 

[dubs283]

Im not sure why i would lose all of the oil if the oil tube that leads in to the drive is plugged so that no oil can get out and no water can get in? I was thinking this would just then be the same as any drive that does not have the reservoir. I can check it manually.

You can do what you like but you are relying on a failing hose and a non factory plug to contain drive oil. The check valve in the drive is open with the drive installed on the bell housing, therefore an old hose and your plug with 15 psi of pressure under load is all there is to keep oil in the drive