454 with Milky oil found on pre-purchse

[beech2000]

Looking at an older boat with twin 454's. I see slightly milky looking oil noted on starboard engine dip stip. Possible causes?
Manifolds, Cracked block, head gasket? Compression check shows all cylinders between 130-140.
I think winter moisture from sitting but have doubts as port engine has normal looking oil.

 

[beech2000]

Looking at purchase of an older carb powered twin inboard cruiser with 454's. I noticed the starboard engine has slight milky appearance on dip stick. whats up? cracked block, heads, manifolds??? all of the above?

 

[jimmbo]

could be

 

[chartersj]

Get them to change the oil and take it for a spin. Just running on the hose sometimes isn't enough to tell

 

[alldodge]

Have trouble thinking of condensation, think more a leak from intake gasket since compression are ok. Was the motor brought up to full running temp and then compression done?

In any case water in the oil, I would think the need to rebuild unless its proven where the water is coming from

 

[tpenfield]

I vote for a cracked block or bad exhaust manifold gasket. You should proceed with caution. 454 engine blocks are a bit pricey.

 

[harringtondav]

Agree with a leak or crack somewhere. My boat sleeps in IA winters, with an oil change before slumber. I've never seen condensation discolor the engine oil.

 

[Scott Danforth]

doubt its condensation.

most likely cracked block from improper winterization or bad manifold to riser gasket.

FYI, a rebuild on a BBC will be about $2500

 

[QBhoy]

Only time I’ve seen condensation showing milky oil is on the inside of the oil filler cap and perhaps at worst a wee bit showing on the rocker gear when looking in. Never really known it to show on the dipstick. That would suggest something else, I’d think.