Merc 3.0 Low Compression 2 & 3

[zbnutcase]

Re: Merc 3.0 Low Compression 2 & 3

That valve seat recession is what happens when unleaded fuel is used in a leaded fuel engine, and can be repaired with seat inserts.

 

[tschmidty]

Re: Merc 3.0 Low Compression 2 & 3

New question for the experienced mechanics:

The gasket I pulled out is all steel. Looking at the manual specifically says 'Do not use steel automotive type gaskets' and the replacement is asbestos composite (I think).

Was the steel one OEM? Is this typical?

 

[Don S]

Re: Merc 3.0 Low Compression 2 & 3

Was the steel one OEM? Is this typical?

No, Merc never used steel. Probably some Auto mechanic or DIYer that didn't know there is a difference or a reason for not using steel, installed it.

 

[Bluestream]

Re: Merc 3.0 Low Compression 2 & 3

New question for the experienced mechanics:

The gasket I pulled out is all steel. Looking at the manual specifically says 'Do not use steel automotive type gaskets' and the replacement is asbestos composite (I think).

Asbestos is no longer used due to liability reasons

 

[cwdjr]

Re: Merc 3.0 Low Compression 2 & 3

I'm no expert, but I would take the head to a machine shop and have them take a look. Maybe it can be reworked--it won't be but a few hundered to have that done. If so, I would buy a new (proper) head gasket and button it back up. Make sure you also replace the manifold gasket and riser gaskets too. Throw a compression gauge on it and get a reading on each cylinder. Maybe I'm going blind but the crack, if you can call it that, on the block does not look that bad, and from what you're saying, I gather it's near the surface and not deep.

Someone please explain to me why this engine is nothing but an anchor at this point? I would like to learn.