4.3L Mercruiser milky oil

[bighh7]

Ive got a mercruiser 4.3 , the oil had water in it . I changed the manifolds and risers , did a compression test and it seemed fine . Did 3 hrs on the boat and have water in the oil again , any ideas ?

 

[thumpar]

Re: 4.3L Mercruiser milky oil

Did you change intake manifold? You should provide more info on exact engine also. Year or serial number would help.

 

[Don S]

Re: 4.3L Mercruiser milky oil

How much water we talking about, thimble full, or a gallon?

 

[90stingray]

Re: 4.3L Mercruiser milky oil

Ive got a mercruiser 4.3 , the oil had water in it . I changed the manifolds and risers , did a compression test and it seemed fine . Did 3 hrs on the boat and have water in the oil again , any ideas ?

Did a compression test on the cooling system or the combustion chambers? You can have a cracked block leaking water into your crankcase and the cylinders have good compression. Please clarify... but i'm thinking cracked block since you had bad manifolds and such.

 

[bighh7]

Re: 4.3L Mercruiser milky oil

Pretty close to a gallon the first time , I pulled the dipstick today and it looks like somebody had overfilled the engine with oil . I guess the water has not mixed yet and is lying below the oil

 

[Don S]

Re: 4.3L Mercruiser milky oil

if it's not milky, the engine wasn't run with the water in the oil. Did the boat sink and the engine go under water?

 

[bighh7]

Re: 4.3L Mercruiser milky oil

Pull the manifolds , did a compression test and found nothing on # 2 cyl . Pulled the head off and the valve spring is broken , the valve broke and went into the piston .The owner says the oil pressure was pretty low when he ran the boat . What would cause the spring and valve to break ?

 

[bighh7]

4.3 Mercruiser valve spring broken

4.3 Mercruiser valve spring broken

Ive got a 4.3l and it broke the valve spring , the valve head ended up in the piston . What could cause this , it did have water in the engine before and i changed the manifolds .I had posted it earlier , any ideas ?

 

[Silvertip]

Re: 4.3 Mercruiser valve spring broken

Re: 4.3 Mercruiser valve spring broken

You possibly answered your own question. And even if water had nothing to do with the failure, sometimes things just happen. Springs can break, keepers can pop off, a rocker arm can come loose and strike the spring retainer. Improper assembly is also possible. But very likely it just failed.

 

[bighh7]

Re: 4.3L Mercruiser milky oil

No when the valve broke it knocked a hole into the water jacket and I beleive thats where the water came in and that would explain why the oil and water did not mix .Thanks for the reply .

 

[Don S]

Re: 4.3 Mercruiser valve spring broken

Re: 4.3 Mercruiser valve spring broken

I'm going to merge your two threads together, you already asked why the spring could break in your previous thread, plus you posted the background of how you found it.
I't best not to repost the same thing in different threads. Gets very confusing.

PS: Valve springs can break just from metal fatigue. Don't forget, the get squeezed together and opened up a bunch of times in their life.