Volvo Penta 7.4gl 1995 Water in Oil

[Kyledv66]

Thanks for the tip. Looking into a shop that will clean and magnaflux them, as well as check the surface and vacuum check the ports for $52 for the pair of heads. Seems like a decent price.

 

[Kyledv66]

Heads got back from the machine shop. No cracks, no rust, and surface is flat. Water jackets not leaking. All is good with the heads. Going to start rebuilding in the next week i'll keep you posted if anything comes up. Hoping that all of this was just bad gaskets.

 

[Lou C]

Well that's good news! Get a nice Fel Pro marine gasket set for the head gaskets and intake and some good exhaust elbow gaskets. Also a thread chaser to clean out the bolt holes in the block and exhaust manifolds. If the head bolts are corroded I'd replace them, I used ARP bolts when I did mine.

 

[Kyledv66]

Hey guys,

Still rebuilding here. I decided to slap on a nice coat of paint before proceeding with the rebuild.

​​I was looking through my pictures, and stumbled across this one when I removed the head gaskets. Rightmost cylinder water jacket, I'm noticing a rust spot that runs almost to the cylinder. You guys think this was the cause of the water in oil?

 

[Scott Danforth]

the right most cylinder had water sitting in it (witness marks on the piston) and the bore has rust. that would indicate that motor had water coming in the exhaust, then into the cylinder head then into the oil

other than that, dont see what you are looking at. you need to clean up the deck surface

 

[Lou C]

Are you referring to the rust stain round the upper right side water passage? While that's a stain there it's hard to say if water came in that way. Usually when head gaskets are blown and allowing in water, the fire rings are split or there is a gap you can see in them. On mine when I pulled off the OE HGs, the fire rings were split on both cyls that leaked water. Most likely it was a previous overheat.

 

[Lou C]

What actually does look suspicious to me is in that right hand side cylinder, the HG at the 3:00 postion….looks like it was starting to distort there....