Oil leaking into water

[Gunner123]

My 1981 Mercruiser I/O is leaking some oil into the lake. The bildge is dry. It seems to be coming from the outdrive exhaust and it leaks when the engine is rev'd. Could it be the power steering cooler is leaking? If so, can I get this tested at a radiator shop? Anything other possibilities for this leaking out of the outdrive such as the rear seal? The outdrive gear lube does not seem to be leaking. Engine oil is fine. Thanks.

 

[littlebookworm]

Re: Oil leaking into water

Is your power steering resevoir getting low? is the oil turning pink instead of red? Is the answers are 'Yes.' then your PS cooler is leaking. You need to flush the lake water out of the system before it begins to rust. You can pull the cooler and have it tested at any radiator shop. They can possibly fix it, as well, depending on the severity of the leak and its location. Hy

 

[Bondo]

Re: Oil leaking into water

My 1981 Mercruiser I/O is leaking some oil into the lake. The bildge is dry. It seems to be coming from the outdrive exhaust and it leaks when the engine is rev'd. Could it be the power steering cooler is leaking? If so, can I get this tested at a radiator shop? Anything other possibilities for this leaking out of the outdrive such as the rear seal? The outdrive gear lube does not seem to be leaking. Engine oil is fine. Thanks.

Ayuh,.... Welcome Aboard,.... Like LBW asks,... How 'bout the P/S oil,..??

It could be leakin' from corrosion, or more likely, from bein' frozen, with water in it...

 

[Gunner123]

Re: Oil leaking into water

The Power Steering reservoir is a little low, almost down to the bottom of the guage stick. I don't recall the last time I checked it. I'll pull the hoses off today and then pressure test the PS cooler and the outdrive gear fluid over the weekend. Anything else you think it could be?

 

[Gunner123]

Re: Oil leaking into water

I took the power steering cooler to a radiator shop who tested it with 40 lbs of pressure. Then I put 15 lbs of pressure into the stern drive gear oil fill for about an hour and it held the pressure. Still getting some oil residue coming out of the exhaust. Tomorrow I"ll look at the plugs to see if they all look okay and I'll do a compression test. Could this be a head gasket problem?

 

[NHGuy]

Re: Oil leaking into water

I once had a car that had valve seal leaks that allowed oil into the combustion chambers. If you have that problem the spark plugs will probably be fouled black.
You say the engine oil is fine, is it holding it's level? That is, are you having to add any engine oil? Bad valve seals will normally cause the level to fall with use.

 

[dubs283]

Re: Oil leaking into water

I took the power steering cooler to a radiator shop who tested it with 40 lbs of pressure. Then I put 15 lbs of pressure into the stern drive gear oil fill for about an hour and it held the pressure. Still getting some oil residue coming out of the exhaust. Tomorrow I"ll look at the plugs to see if they all look okay and I'll do a compression test. Could this be a head gasket problem?

first off you need to identify what type of oil it is you are seeing in the water, then you can start looking at specific components

when you pressure tested the drive, did you do it with the drive off the bell housing and drianed of lube??

or did you just pressurize the monitor bottle??

does the boat have trim tabs??

what does the power trim oil look like??

 

[achris]

Re: Oil leaking into water

How about we start with the obvious question.... 1981 Mercruiser what? Does it have closed cooling? Where are you seeing this oil?

 

[Gunner123]

Re: Oil leaking into water

1981 Mercruiser 350cu 260 horse with Alpha drive with fresh water cooling.

So far I have:
1) Pressure tested the sterndrive with the gear oil drained but drive still on. 10 Lbs overnight
2) Took the PS cooler off and took it to a radiator shop where it was tested at 40 lbs
3) Did a resistance test on the spark plug wires
4) Pulled the plug wires from the distributor cap one at a time while the engine was running. All had spark and all slightly affected the engine running the same way.
5) Did a compression test with all cylinders at 110 PSI
6) Inspected all spark plugs and they are all in satisfactory condition

The oil (or fluid) doesn't have a smell like you'd expect with fuel or gear oil.

The boat has trim tabs.

Regarding the power trim, the reservoir is a bit low but I haven't check this in a long time. Would this only leak out if the drive was raised or lowered? With an electric pump, I wonder if this could possibly be the cause. No apparent leaks around the cylinders.