3.0 merc head gasket

[jthor3277]

Well my boat problems persist. I was timing the engine today and noticed a skip in the motor. I did a compression check and found the #2 cylinder at 75psig. Not good news. All the other cyls are fine around 110 psig. The plugs are dry and in great shape so I am thinking head gasket. Is this difficult to change on a 3.0L? Also I noticed a fiberglass patch on my block. If my block is cracked and has a makeshift repair...I am going to set it on fire!! Any ideas or is it worth fixing?

 

[Bifflefan]

Re: 3.0 merc head gasket

LOL.... Sorry man
its not hopeless, but I do feel your pain. More than likely there is a problem with the block (patch area) but until you know the reason for the low compression, you dont know.
If you have to pull the motor anyway its a good time check the patch.

 

[jthor3277]

Re: 3.0 merc head gasket

Is it common to see a patch on the block? Does the motor have to be pulled to change the head gasket? I an aircraft mechanic and have no clue on recips!

 

[thannah84]

Re: 3.0 merc head gasket

No, it is not common to have a patch on the block...That means it was cracked at one point and someone, rather than fixing it right by welding it, patched it....The head gasket can be changed without pulling the motor, but if the engine is pretty confined, it could be a pain.

 

[jthor3277]

Re: 3.0 merc head gasket

Lets keep our fingers crossed when I pull the head. I hope it's just the jacket. If not you boys will be able to see the flames for miles!!