Motor oil milky

[scott8058]

Hi sry if this is in the wrong spot but I changed my motor oil today and saw it was a milky brown color. I started it yesterday and it ran a lil rough but smoothed out and sounded good after a few mins and warming up. Today I warmed it up to thin the oil and when I changed it it was milky looking. We had a coooold winter but I pulled all hoses and put 3 gal of antifreeze in thru stat back in the fall so I don't see how it could have cracked the block. Motor is a merc cruiser 350 w alpha one, is it poss that condensation built up over the winter or does this seem like a major problem. Thanks for any help

 

[Gyrene]

Re: Motor oil milky

Sure sounds like a head gasket. Would have to be a ton of condensation to turn oil milky...
You have noting to lose by running it for a while and changing oil again - if it's milky again, then you know for certain you need a head gasket.


And this is the wrong section - it says "not engine topics"

 

[scott8058]

Re: Motor oil milky

Yes I saw that but the engine FAQ hasn't anything new in forever so I thought I'd put here and let the mod move. Here's my next q is that I used a pump on the dipstick to change the oil, is that goin to leave some of the milky oil in there? I haven't refilled the motor yet jus pumped it out and pulled the filter. Also w the head gasket how would that go bad if I've nvr even come close to over heating her? Isn't that very rare for it to fail w/o that?

 

[alldodge]

Re: Motor oil milky

Condensation would not cause milky oil. From what you have stated it is my opinion that something has cracked. Start with the basics and finish changing the oil, run it a while and check the oil. If you find water again, start with a compression test because it's easy. If all looks good start pulling the exhaust and heads

 

[flipbro]

Re: Motor oil milky

mercruiser engine repairs is were you need to be with this. Those guys can help you out! Also you must have been looking at the wrong forum cause there are new posts every minute over there. Good luck on your problem! FWIW I would say head gasket or cracked block over winter!! I would also pressure test the block before i run it to much!!

 

[scott8058]

Re: Motor oil milky

Ok so it ran great like 8 -10 times a month all last season, so do you think the water was there all last yr or happened yesterday when I first put the muffs on it? Also would winter affect the head gasket?

 

[thumpar]

Re: Motor oil milky

Pressurize the cooling system and listen for air. There is a reason they say "air don't freeze".

 

[bspeth]

Re: Motor oil milky

If you did everything in the winterizing question thread you shouldn't have a cracked block.

 

[HT32BSX115]

Re: Motor oil milky

Ok so it ran great like 8 -10 times a month all last season, so do you think the water was there all last yr or happened yesterday when I first put the muffs on it? Also would winter affect the head gasket?

Howdy,


Forget about the head gasket. Head gaskets rarely fail on marine engines.

Start with pressurizing the block. This is the time of year for cracked blocks if you erred in winterization.

The ONLY way to rule out a cracked block is to pressurize it (assuming it holds pressure)

 

[bonzoscott]

Re: Motor oil milky

What is important is: How high on the dipstick was the oil? Is the boat new to you as of last season and was this your first winterizing? I don't think pouring antifreeze on top of water will do it. Best to drain. Your motor may be trashed, but can't tell from limited details. Rather than pressurizing the cooling system, just change the oil and run it for a good bit then check the oil level on the stick. If it is a quart high - cracked block. If not, you may have hope. Did you drain the exhaust manifolds?

 

[HT32BSX115]

Re: Motor oil milky

We had a coooold winter but I pulled all hoses and put 3 gal of antifreeze in thru stat back in the fall so I don't see how it could have cracked the block.

I don't see anyplace in your first post that you drained the block FIRST.

If you did not drain the block BEFORE pouring the antifreeze in, you likely did get a freeze in an pool of water that didn't mix thoroughly (or at all).

After changing the oil and running it you'll find out.


Also, in the future, NEVER change the oil at the beginning of the season. Always change your oil at the end of the boating season. This way you have fresh clean oil in the engine when it sits the longest!


Good luck,



Rick

 

[stonyloam]

Re: Motor oil milky

Agree with HT, if you did not drain the block before adding antifreeze there is a good chance that you have a cracked block.

 

[Bt Doctur]

Re: Motor oil milky

Without leaving out any of the steps, EXACTLY how did you winterize the motor?
"Hi sry if this is in the wrong spot but I changed my motor oil today and saw it was a milky brown color. I started it yesterday and it ran a lil rough but smoothed out and sounded good after a few mins and warming up"

A classic symptom of water in a cylinder and a fouled plug that cleared.

 

[scott8058]

Re: Motor oil milky

Ok sorry, I when id put it away I ran and fogged it til it died and then drained both block drains and exhaust manifold drains. Then I pulled all 6 I think hoses going to stat and I front of, even the one on the bottom power steering cooler or whatever it is. Then pulled the stat and filled w antifreeze. After that I opened all four drains again to make sure it was only pink coming out. I pulled the prop greased the zerks and prop shaft, the only thing I didn't do is change the oils. I jus don't see how I could have a cracked block.

 

[scott8058]

Re: Motor oil milky

And to answer bonzo when I went to change the oil and pulled the dipstick I didn't really think of it but it was higher than it should have been now that I think of it. And this is our 3rd season and I've winterized twice, first yr no antifreeze and came out ok, this past fall I researched and obsessed lol over doin it right.

 

[Firefighter3011]

Re: Motor oil milky

Were all your operating temperatures normal last season ? I bought my boat last year and the previous owner had removed the thermostat for winter and didn't tell me. I ran it 5 times last season and the temp gauge wouldn't even come off the bottom. I figured it was a broken gauge until I laser temped the oil pan and the block both reading about 90 degrees after a full load run. Now I do have a bypass cooling system but my oil was garbage milky and smelled awful like raw gas from not burning off combustion moisture. Make sure your oil temperature is around 200 degrees at least enough to steam out natural occurring condensation and combustion bi product. Needless to say now I have a thermostat installed and my temperature gauge is in fact in working order.

 

[Walt T]

Re: Motor oil milky

Most of the cracked blocks we hear about every spring were winterized with antifreeze. Sad, but true.

 

[HT32BSX115]

Re: Motor oil milky

Most of the cracked blocks we hear about every spring were winterized with antifreeze. Sad, but true.

Yes.............


"Someone" on this forum always says "Air Don't Freeze" (he also says "any Grease..........")


The key here is you MUST drain the water. (period)

if you just pour antifreeze in the available holes and you neglect to drain water in any ONE place, the water left in that "place" WILL likely NOT mix adequately to prevent freezing. If it happens to be in a "little nook" in the block............well, we see those results every year about this time............

Ok sorry, I when id put it away I ran and fogged it til it died and then drained both block drains and exhaust manifold drains. Then I pulled all 6 I think hoses going to stat and I front of, even the one on the bottom power steering cooler or whatever it is. Then pulled the stat and filled w antifreeze. After that I opened all four drains again to make sure it was only pink coming out. I pulled the prop greased the zerks and prop shaft, the only thing I didn't do is change the oils. I jus don't see how I could have a cracked block.

Changing oil has nothing (of course) to do with a cracked block.

What you did *should* have removed all the water, and doing that, you DO NOT need to use antifreeze at all............. (you did use a piece of wire or other 'poker' to clear all drains [especially block drains] of rust flakes while draining, didn't you?)

 

[nola mike]

Re: Motor oil milky

Says he had a/f pouring from the drains, so presumeably they were clear...

 

[HT32BSX115]

Re: Motor oil milky

Says he had a/f pouring from the drains, so presumeably they were clear...

Yes, you're right.

But then, just about everyone who has a freeze "event" after doing the anti-freeze "thing" says that.................A block pressure check will tell for sure.