Water In Oil - Exhaust Riser?

[piasajake]

I have a 1985 Mercruiser 140. I have been getting water in the oil. I'm pretty sure it is not casued from freezing, because it started at the end of last season before any freezing temperatures. The The intake/exhaust manifold was replaced with a new one. The head was also removed and visually checked for any problems and reinstalled with new gaskets.
My engine has the older style 2 piece exhaust riser that has the offset adapter. The boat had possibly been used in salt water at one time, but I don't know for sure.
I was told that there could be a problem with the riser causing water to get into the oil. I've changed out the oil 3-4 times and it seems to take about the same amount of running time to show the water mixing in the oil. I'm thinking of just replacing the old 2 piece riser with a new one piece version to see if that was the problem. Could water be getting in thru the water pump/circulator, thermostat housing, etc.? The engine runs great except for the water in the oil problem.

Any other suggestions would be appreciated!

 

[piasajake]

Re: Water In Oil - Exhaust Riser?

NOBODY has any suggestions or tip????

 

[ziggy]

Re: Water In Oil - Exhaust Riser?

i ain't the pro here. but i'll make a suggestion. i think your on the right track. replacing the riser that is. i think if ones done, the other is close behind it... replace as a set, manifold and riser..

 

[Bt Doctur]

Re: Water In Oil - Exhaust Riser?

Unbolt the riser and look inside, if it`s wet ,it`s leaking and fouling #4 plug

 

[rs2k]

Re: Water In Oil - Exhaust Riser?

It could also be a bad head gasket. In any case the exhaust manifold needs to come off. I'd take it off and inspect it.

 

[piasajake]

Re: Water In Oil - Exhaust Riser?

Thanks for the suggestions.
It is a brand new Barr intake/exhaust manifold. I also checked the head gasket and it looked fine and replaced it with a new one. All new gaskets associated with the new intake/exhaust manifold and used the proper torque settings and patterns. When the head was off cylinder #2 (2nd one back from the front of the boat) looked a little different that the other 3. Cylinder 2 looked like it was the one that was getting water in it.
I went ahead and ordered a new Osco riser kit that replaces the 2 piece older style riser assembly. I guess I will see if that was a fix after I get it and put it on. The old one was pretty crusty on the inside. I let it soak in muratic acid for a few days to try and clean it up and took a wire wheel to it. I hope the new riser is the fix. I was pretty close to just replacing the engine and getting a new long block, but if it is the riser that would still do it to a new engine after swapping all the old parts to the new long block.

Any other suggestions are always welcome!

 

[piasajake]

Re: Water In Oil - Exhaust Riser?

I got the new Osco riser and installed it. Changed the oil and let it run on the hose for about a half hour. The oil still looks like it is getting water in it. It got milky again.

After replacing the intake/exhaust manifold and now the riser, along with a new head gasket, what else could possibly be the problem? The head looks visibly ok. The engine runs fine with no missing. I know there will probably be a few people that jump in and say a cracked block right off the bat.
But is there any other possible things I can check where water could get into the oil before I scrap the engine and get a new one?

Is it better to get a new long block or rebuild? Maybe I should just sink it...

 

[rs2k]

Re: Water In Oil - Exhaust Riser?

I got the new Osco riser and installed it. Changed the oil and let it run on the hose for about a half hour. The oil still looks like it is getting water in it. It got milky again.

After replacing the intake/exhaust manifold and now the riser, along with a new head gasket, what else could possibly be the problem? The head looks visibly ok. The engine runs fine with no missing. I know there will probably be a few people that jump in and say a cracked block right off the bat.
But is there any other possible things I can check where water could get into the oil before I scrap the engine and get a new one?

Is it better to get a new long block or rebuild? Maybe I should just sink it...

Most GM 140s tend to crack eternally before they crack internally. You may have a warped head. To check that you need to take off the head and check it with a straight edge and feeler gauges.

There are only so many places on a GM 140 that water can get into the oil. From the heads, from the block, from the exhaust manifold.

That leaves only a few possibilities:
1. There was still water in the engine after you changed the oil and the engine never got hot enough to boil it out of the oil.
2. Bad new exhaust manifold.
3. Incorrect cam shaft causing water to be sucked into engine during savaging.
4. Cracked head.
5. Warped head.
6. Bad head gasket.
7. Warped block.
8. Cracked block.
9. Gremlins.

 

[piasajake]

Re: Water In Oil - Exhaust Riser?

Thanks for the list of possibilities. I have debated taking it to a boat shop to have the problem found, but that looks like it will probably be around $300 to have that done. I would rather put that money towards a new long block if that is what I'm going to have to do anyway.

The odd thing about how and when this showed up was, it was at the end of the season, after a trouble free summer of many outings, and it never overheated or was in freezing temperature. That is why after reading some other postings I thought it could be a head gasket, intake/exhaust manifold or the riser. The old head gasket also looked fine. After replacing all 3 items it seems to have not fixed the problem. I may change out the oil one more time to see if it was water that was still in the engine.

I envy people with new worry free boats...

 

[rs2k]

Re: Water In Oil - Exhaust Riser?

I envy people with new worry free boats...

I don't think there is such a thing. Even people with $1000 per month boat payments seem to have their share of trouble. If you want a worry free boat... go to Walmart. I think they have some rubber rafts on sale.

I went through a similar problem with my 28' cabin cruiser last week. I kept getting water in the port engine's oil. I took off the heads and checked the heads and block for warpage and cracks then replaced the head gaskets. After doing all that work I still was getting milk shake colored oil. I then replaced the gasket in the exhaust manifold, changed the oil, and tried again. I still had milky oil. I knew the thermostat was bad, so I went ahead and replaced it as well as the oil once again. I fired it up and still had milky oil, but it was nowhere near as bad before. I went ahead and let the engine idle for about 10 minutes with a shop-vac hooked up to the crank case vent to put the crank case under a vacuum (water boils at a much lower temperature when under a vacuum). After about 10 minutes I check again and I had clean oil. The bit of water that was still in the engine and the oil had boiled to steam and had left the engine.

 

[piasajake]

Re: Water In Oil - Exhaust Riser?

Thanks for the tip! Maybe I'll try that when I change the oil out again. I'll let it run for a little longer next time too.

Thanks again! Any other tips or suggestions are appreciated.

 

[rs2k]

Re: Water In Oil - Exhaust Riser?

Make sure you use a wet/dry vac if you decide to use a vacuum. You can get those things cheap at Walmart. I just hooked it up to one crank case breather and plugged the other one. Your 140 should only have one breather.

Don't forget to change the oil filter when you change the oil. You want to get all that water out of there as well.

 

[bruceb58]

Re: Water In Oil - Exhaust Riser?

You need to pressure test the block to see if there is a leak.

 

[bruceb58]

Re: Water In Oil - Exhaust Riser?

Make sure you use a wet/dry vac if you decide to use a vacuum. You can get those things cheap at Walmart. I just hooked it up to one crank case breather and plugged the other one. Your 140 should only have one breather.

Don't forget to change the oil filter when you change the oil. You want to get all that water out of there as well.

The amount of vaccum you would need to lower the boilng point of water is WAY more than you could possibly do with a shop vac.

 

[rs2k]

Re: Water In Oil - Exhaust Riser?

The amount of vaccum you would need to lower the boilng point of water is WAY more than you could possibly do with a shop vac.

A shop vac can lower the boiling point of water by 20+ degrees Fahrenheit.

Water boiling at 190 degrees is better than water boiling at 212 degrees when you're trying to get it out of an engine.

 

[bruceb58]

Re: Water In Oil - Exhaust Riser?

The best way of getting water out of the oil in an engine is to warm up the engine and change the oil. Running a shop vac to the breather of an engine thinking you are going to lower the boiling point of water is just silly. if the water is in the oil, the oil will be getting emulsified. I really challenge you to be able to reduce emulsified oil back to normal oil with normal engine temps running at 160 degrees.

This poster is getting water in his engine still. Worrying about getting the last of any water out of the oil would be a good problem to have. He needs to find the source of the water and the pressure test of the cooling passages is the first step....not hooking up a vacuum cleaner.

 

[rs2k]

Re: Water In Oil - Exhaust Riser?

My point was that the water in the oil in the lifters, valley, journals, and pump of my engine was enough to make fresh oil look like it was still getting water into the engine. I was amazed to see how little water there was in the oil that looked milky. (I let the water settle out of the oil). On a whim I tried letting the oil get up to temp to see what would happen. In my case it worked quite well.

Since oil in an idling engine may not go above 200 degrees, and we all know that water boils at 212 degrees at 29.92 inches mercury, and we all know that oil and water do not mix which means the boiling point of the water in the oil will not change, and we all know that the shop vac I used will drop the mercury level to 19 inches, and we know that at 19 inches of mercury water boils at around 190 degrees, it seemed to make sense that dropping the boiling point of water to 190 degrees would make a difference. Silly or not.

 

[bruceb58]

Re: Water In Oil - Exhaust Riser?

Oil and water do mix. That is what emulsification is.

Please take a look at the OPs posts. He says the oil gets milky...emulsified!!!!

 

[rs2k]

Re: Water In Oil - Exhaust Riser?

Oil and water do mix. That is what emulsification is.

They do not mix, they emulsify. It is a suspension, not a solution.

A mechanical mixture does not effect the chemical properties.

 

[bruceb58]

Re: Water In Oil - Exhaust Riser?

They do not mix, they emulsify. It is a suspension, not a solution.

A mechanical mixture does not effect the chemical properties.

I agree. Its not a solution.

I still challenge you to get the water out of an emulsion. If you could do that, we would not have the problems we have with water and ethanol emulsions. You could be a gazillionaire.

He still needs to pressure test the block. I am really surprised you have not suggested this yet. It is the first step. Not pulling heads to look for head gaskets.