Water in engine oil - Mercruiser 5.7

[qystan]

To share a strange one.<br /><br />I have been having a problem with water in my engine oil. Not much water, just enough to create some milky streaks in the oil when viewed through the oil fill cap.<br /><br />Had the heads off to examine them, block, oil galley area and the inlet manifold - nothing.<br /><br />Reassembled and while test running it found water dripping out from the upper end of the lower shift cable barrel. It drips onto the valve cover vent tube and flows in via the vent connection. <br /><br />Drive gasket and water transfer o-ring job to follow. At least the problem is found

 

[rabidfish]

Re: Water in engine oil - Mercruiser 5.7

Safe bet you're gonna need a shift cable soon.

 

[rodbolt]

Re: Water in engine oil - Mercruiser 5.7

and once you fix the shift cable fix the upper shift shaft seal that caused all this headache. . the easiest fix is the new style bushing kit rather than the two seals. but the factory seals failed a lot and rapidly.

 

[tommays]

Re: Water in engine oil - Mercruiser 5.7

Oystan<br /><br />did you buy that aftermarket drive?<br /><br />tommays

 

[qystan]

Re: Water in engine oil - Mercruiser 5.7

Yep, new cable on the way. The leak should be from the water transfer face, I get the leak on mufflers. The shiftshaft seal was changed last year and should be good.<br /><br />Tommays<br />Yes, I am running the SEI drive (lower only) for about 4 months. So far its been good.

 

[rodbolt]

Re: Water in engine oil - Mercruiser 5.7

water transfer is on the other side of the shift slide pocket and has nothing to do with water in the shift cable. the only normal ways to get water in the slide area is a defective upper shift shaft seal or a defective drive mounting gasket<br /> or the cable threads are leaking where the cable threads into the bell housing.<br /> or maybe the cable jacket is cut somewhere

 

[qystan]

Re: Water in engine oil - Mercruiser 5.7

Rodbolt<br /><br />Missed this part in your post.<br /><br />" the factory seals failed a lot and rapidly"<br /><br />Do you mean the new bushing kits are also prone to failures? I have the bushing kit installed.<br /><br />Thanks.

 

[rodbolt]

Re: Water in engine oil - Mercruiser 5.7

could be. if it was a merc kit it has the same junk seals as the original just now they are in a brass block. I rarely replace the seals in the bell hosing, usually I use the kit that is the upper shaft busing and seal carrier all in one, but there are some other points that can leak water intothe shift slide pocket. all need to be checked. seams the factory merc seals use a plain steel backing. seems the plain steel backing does not last long when exposed to exhaust gas and saltwater. seems after they leak saltwater into the pocket bad things happen to the cable. the support wires rust and clamp the cable to the inner jacket causing shift interrupt then gearcase problems.

 

[Don S]

Re: Water in engine oil - Mercruiser 5.7

Here's the part number and picture of the new style bushing and seal.<br />Also, what year is your engine and drive?<br /> <br /><br />Bell housing seal and bushing

 

[qystan]

Re: Water in engine oil - Mercruiser 5.7

Thanks Don<br /><br />I changed to the new bushing kit early last year. Its the one shown in your link.<br /><br />Engine is 1989. Drive s/n OD485637 (1990?). Lower unit was changed to the SEI drive late last year.