Milky Oil

[prstack7]

I have been reading and troubleshooting. Here is what I have done so far:
1. Changed the oil 5x. It now looks clear.
2. Pressure tested the manifold. It passed.
3. Pressure tested the block. It passed.
4. Removed the manifold and valve cover. Everything looks good. The valve cover gasket came apart on removal, so it's possible that was a source of infiltration.
5. Examined externally the water pump. I don't see any evidence of leaking seals.

Upon reflection, I wonder if an episode this summer where I sprayed water around the engine compartment (it was not intentional, but I don't want to talk about it ) caused this problem. I had milky oil 2 years ago, but that cleared up after changing the oil 3x. Any ideas?

Side note: should I use gasket sealant when putting the new gasket on the valve cover?

[Dave Neptune]

Yes use a good Permatex Aviation Grade or Number 2 grade.

The water pump can leak into the oil via the rear seal. If the water getting in has been consistent it's a likely suspect. Intermittent could be from the hush hush spraying.

Dave Neptune

[Easy Rider]

Are you raw water cooled?

[prstack7]

Originally Posted by Easy Rider

Are you raw water cooled?

Yes, I am.

[zellerj]

Water in the oil does not have to be from an engine issue. The only time I had water in the oil was a result of large wakes hitting my stern when I was stuck on a sandbar. If you do not have a plate over your exhaust through hull, then a wave or wake could have pushed water up through the exhaust and into your engine. Also extended cranking with the cooling water through hull open can fill your water lift muffler (if you have one) and also push water into the crankcase through an open valve.

[Easy Rider]

Lots of info regarding this topic on the forum. I'm sure others will chime in and help figure out what's causing it. What about the possibility of over cranking with the sea cock open? Any restrictions in the exhaust?

[prstack7]

I have been reading the various threads on this issue. I'm hoping that this was the result of an event, such as the water spray in the engine compartment or infiltration through the exhaust (no plate over my tail pipe). I was able to rule out cracks in the manifold or the block, plus engine compression test shows great on all 4 cylinders, so that's good. The boat's on the hard now, so it will have to wait until next year to know for sure. It was definitely not extended cranking. The one bummer is that, while putting the valve cover plate back on, I broke a bolt by overtightening. Now I have another problem to solve.

[ArtJ]

Have you checked the head?

[sastanley]

Originally Posted by prstack7

I have been reading the various threads on this issue. I'm hoping that this was the result of an event, such as the water spray in the engine compartment or infiltration through the exhaust (no plate over my tail pipe). I was able to rule out cracks in the manifold or the block, plus engine compression test shows great on all 4 cylinders, so that's good. The boat's on the hard now, so it will have to wait until next year to know for sure. It was definitely not extended cranking. The one bummer is that, while putting the valve cover plate back on, I broke a bolt by overtightening. Now I have another problem to solve.

Once you get the broken bolt extracted, this is a great time to convert to studs!

[prstack7]

Originally Posted by ArtJ

Have you checked the head?

Yes, I did a compression test and all 4 cylinders were around 115.

[prstack7]

Originally Posted by sastanley

Once you get the broken bolt extracted, this is a great time to convert to studs!

That's a good point. I hadn't thought of that.

[prstack7]

Boat launched, and still have milky oil issue after changing oil again. My understanding is I should next go with the water pump seals. BTW, thanks for the convert to studs idea. It was definitely the way to go.

[Surcouf]

Originally Posted by prstack7

Boat launched, and still have milky oil issue after changing oil again. My understanding is I should next go with the water pump seals. BTW, thanks for the convert to studs idea. It was definitely the way to go.

First: make sure the water seals "wheep hole" is not blocked. This hole can be seen at 0:37 of the video
https://www.youtube.com/watch?v=lKKJc02PAQE
It is located after the seals, at the bottom side of the pump casing. Its duty is to let drain any water that would go past the seals (seals located around the shaft). If seal leak become simportant, it will potentially overflow that hole an go into the oil. But if you have 0 water draining out AND this hole is clear, I would scratch my head a little more around potential other culprits...

[capnward]

+1 on it being the seals in the pump. This happened to me. Once water got past the first seal into the bearing, the shaft wore in the seized bearing and created a wobble in the shaft that destroyed the next seal, which sent water shooting right past the open 'weep' hole into the crankcase. The weep hole was definitely weeping, more like pouring, and cooling water was diverted from engine cooling to the bilge and the crankcase. The engine overheating was what clued me into the problem. The pump was completely failed, but the impeller was fine.
So, you may need a new shaft in addition to new seals. Having a working pump as a backup is a good idea.

[prstack7]

How can I tell that the weep hole is clear?

[Surcouf]

Originally Posted by prstack7

How can I tell that the weep hole is clear?

stick a screw driver trhough it. If you can hit the water pump shaft, it is not blocked

[capnward]

If the weep hole leaks when engine is running, it is clear, and you need to work on the pump. If you have the problem I had, there will be no doubt the weep hole is clear. I don't know what could clog the weep hole, which is pretty big, unless you have the old-style pump with the grease cup and have been forcing grease past the seals. And even if the weep hole is open, the pump could still be the source of water in the crankcase oil, if the seals are completely shot.