Mercruiser 260 (Chevrolet 350): water in oil & #1, #3, #5 cylinders

[thedillybar]

#1, #3: 85psi compression
All others: 140-160psi compression

Pressure test of coolant system showed leaks into #1 & #3

Head gasket shows a break between cylinder & water jacket on #1 & #3.

Any ideas what could cause this?

 

[Bondo]

Re: Mercruiser 260 (Chevrolet 350): water in oil & #1, #3, #5 cylinders

Ayuh,... My guess is, it's a Steel gasket, that rusted away...

 

[thedillybar]

Re: Mercruiser 260 (Chevrolet 350): water in oil & #1, #3, #5 cylinders

Hmm it's a "marine" head gasket from a local dealer that I installed 3 years ago. Not sure what it's made out of though.

 

[Fordiesel69]

Re: Mercruiser 260 (Chevrolet 350): water in oil & #1, #3, #5 cylinders

That is not a marine HG.

 

[thedillybar]

Re: Mercruiser 260 (Chevrolet 350): water in oil & #1, #3, #5 cylinders

How can you tell a marine HG from a non-marine?

 

[dirtdog38]

Re: Mercruiser 260 (Chevrolet 350): water in oil & #1, #3, #5 cylinders

have u played with the time any that can do it. even bad gas can if u get some prefire in that hole its going somewhere. or just was lose and out of torque. how long did u run that way if very long your bearings ar gone but its a cheap fix 2 or if u just want to run and the head and block look good between the blow. run it.

 

[AZSenza]

Re: Mercruiser 260 (Chevrolet 350): water in oil & #1, #3, #5 cylinders

Too much corrosion of that gasket to be stainless, it just corroded away. Replace and run some more. If the other side has the same gasket, I bet its right behind it.

 

[thedillybar]

Re: Mercruiser 260 (Chevrolet 350): water in oil & #1, #3, #5 cylinders

Thanks all. Guess I'll be replacing both head gaskets & put her back together.