milky oil

[carsflame]

hi everybody i have a 2000 2800 with twin 4.3 just got boat lots of little problems i changed all filters and oil today port side engine oil was very clean but a little over full but the starboard engine was over full and very milky water getting in some were i thinking head gasket or typical intake gasket any thoughts motor run good only has 160 hrs i will do a leak down test when i get a chance to get boat back to shop thx

[mmwjr]

First welcome aboard.

Yep milky oil is a sign of water getting in. Intake and head gaskets are a start, also exhaust manifold to elbow gasket. After that need to look into crack in exhaust manifold, elbow, riser is you have them, and head. Leak down (compression test) is a good start regarding the had gasket and potential cracked head. While the engine has 160 hours how many on exhaust? i.e. was the engine rebuilt and used old exhaust.

Keep us posted with what you find after the compression test and let's take it from there.

[carsflame]

Originally Posted by mmwjr

First welcome aboard.

Yep milky oil is a sign of water getting in. Intake and head gaskets are a start, also exhaust manifold to elbow gasket. After that need to look into crack in exhaust manifold, elbow, riser is you have them, and head. Leak down (compression test) is a good start regarding the had gasket and potential cracked head. While the engine has 160 hours how many on exhaust? i.e. was the engine rebuilt and used old exhaust.

Keep us posted with what you find after the compression test and let's take it from there.

thx mike i am car & truck mechanic for 25 year getting into boat is different can water get into motor throw the exhaust? or riser?i did change the exhaust rubber coming off the riser it was badly split and burnt maybe riser is cracked?

[mmwjr]

The exhaust on a boat is water cooled since it is in a confined space. The manifolds are heat exchangers were water flows around the exhaust chamber in an outer jacket. The elbow is similar but also injects water directly into the exhaust stream to cool it before discharge. The elbows typically clog/crack before the manifold. I suggest you remove the elbow and inspect it. Remove hose off the bottom of the manifold to drain the water out as the interface is a wet joint (water flows from the manifold into the elbow), undo the 2 large hose clamps, then remove the 4 bolts that hold it on. Once removed look as the section that mated to the manifold you will see the outer water passages. These should be open and clear of any scale. Then look at the side that was in the rubber hose, at the top is the passage tha injects the water into the exhaust it should be clear as well.

These systems ussually need to be replaced every 500 hours or 10 years depending on fresh vs. salt water use and if the engine is flushed after useage.


BTY: I would still do the compression test if nothing else as a baseline to the engines health.

[carsflame]

Hi mike and everybody ok did compression test was very good 165 to 175 cold test throttle open also pull manifold and riser off did not see any cracks very rusty i can see slow water flow tomorrow leak down test to see if head gasket is leaking down if not i guess i will pull intake because i no gm had a big problem with that thx

[mmwjr]

I would also check temps on manifolds and t-stat housing using an IR handheld thermal gun. None should be greater than 160 F

Cracks in the manifolds are very hard to spot wit all the rust. A picture of what you are seeing would help

[mmwjr]

Since compression passed I agree the intake is thenext logical things. If the exhaust is bad it is just beginning and not that much water would be in the oil. Also is it is leaking it will soon result in melted exhaust valve or seat as it raises exhaust temp. You have never said if they have more than the 160 hours mentioned on the engine. May need to consider replacing them as when hey fail if not caught soon they will kill the engine.

[carsflame]

Originally Posted by mmwjr

since compression passed i agree the intake is thenext logical things. If the exhaust is bad it is just beginning and not that much water would be in the oil. Also is it is leaking it will soon result in melted exhaust valve or seat as it raises exhaust temp. You have never said if they have more than the 160 hours mentioned on the engine. May need to consider replacing them as when hey fail if not caught soon they will kill the engine.

hi i am going to change both manifold and risers because its to hard get all the rust out and for sure i am changing intake gasket but first i have to do a leak down test just to make sure the head gaskets are good but i am on the road on till friday i will let u no what i see thx dave

[mmwjr]

Dave, what do you mean by leak down test? You stated you performed a compression test that passed. Do you mean on the coolant side? If so unless you have a closed system (heat exchanger) that was optional the standard system is open and won't build any pressure.

[carsflame]

Ya you're right it will be Very hard to do that test All I can do is put air into the cylinders Make sure the valves are closed Put about 125 PSI of Air in each cylinder Watch to see if the gauge goes down Let's hope the valves are very dirty Sorry about the email I did it off my phone I ordered my new manifolds and risers today When I get home I'm gonna pulled intake off Keep your fingers crossed thanks Dave

[mmwjr]

Or you could get a compression guage that screws into the spark plug hole. Crank the engine and let the piston build up the pressure ~ 150 psi and let it sit to see if it holds.

If you get 150 psi this will tell you right away the headgasket, rings and are good and valves are closing.

[Nehalennia]

You may indeed have a leaking manifold that is leaking into the cylinders. How long has it been since you've (or the previous owners) replaced the manifolds?
If you do replace them check out the newer "dry joint" style. I have them on my boat. Less risk of future leaks.
Also, don't run the engine with the oil milky to check temp. Change the oil at least, but I think you're on the right path, pulling and verifying these conditions.
http://www.mercexhaust.com/oem-mercr...manifold-2002/
[video=youtube;E3KN8IIh4Fw]

[carsflame]

Originally Posted by carsflame

Ya you're right it will be Very hard to do that test All I can do is put air into the cylinders Make sure the valves are closed Put about 125 PSI of Air in each cylinder Watch to see if the gauge goes down Let's hope the valves are very dirty Sorry about the email I did it off my phone I ordered my new manifolds and risers today When I get home I'm gonna pulled intake off Keep your fingers crossed thanks Dave

hi everyone well i had a chance to get back to boat very busy at work.But anyway last saturday i changed intake gasket ,gasket looked good but there was rust at all corners of head where water goes through, intake not good and intake bolts were very loose, cleaned everything reassembled put new up graded gaskets a lot better (thicker) today i replaced new manifolds and riser changed oil and filter again. put a set of plugs in started motor ran great ran it for one hour checked oil no water looks good i guess i got lucky. Thanks for your input mike it did help NOW only if i could find the starboard vent cover that says maxum ok in till next time thanks

[mmwjr]

cars, that's great news. Interesting that it was the intake leaking as that is the same issue mrxitmtr (sp) had. He just got his running again as well.

Sorry can't help with the vent cover