Need help with dad's boat-4.3 vortec

[hvymtl939]

So, my dad traded some junk a few months back for a 1996 Monterrey Montura 186. 4.3 vortec 4 barrel motor with an alpha drive.

Previous owner had a jasper rebuild put in. Took it to the lake without swapping the impeller, and she got hot. At a minimum, head gaskets are shot. Dad ran it for a bit on the house, and sure enough, milkshake oil. He said besides that, the motor sounded good for the short time he had it running, ie no detectable bearing noise, etc.

Not wanting to miss the season, he purchased a running boat, and has been using that since. The Monterrey has been sitting, and he just doesn't have the time to work on it.

So, he's bringing it to my house this weekend since I have extra storage space. Figured I might mess around with it and see if I can get it running. It's a clean boat in great shape for being 22 years old, minus the major motor issue.

So, all that said, what would you guys recommend? Throw a set of head gaskets and an intake gasket (possible culprit) on it and see what happens? Anything else I should check for? Figure if I can get it running for a few hundred in parts, I'll go for it. If that doesn't solve it, we'll just part out.

 

[alldodge]

Pull the heads and have a look to figure if that's all it needs besides the impeller/pump. Use a straight edge on the block and different angles to see if it is still flat. If block is good and no cracks, have the heads redone and put it back together

 

[hvymtl939]

Pull the heads and have a look to figure if that's all it needs besides the impeller/pump. Use a straight edge on the block and different angles to see if it is still flat. If block is good and no cracks, have the heads redone and put it back together

What would need redone on the heads? Burned valves, potentially? Warps?

 

[hvymtl939]

Second thought...would it be worth the effort to just try and drop in a dime a dozen junkyard 4.3 and port over the marine parts?

 

[alldodge]

If the head gasket blew the head probably warped a bit. So the heads get resurfaced and valves done, and for 200 to 250 your back up and running.

If you try a junk yard get a truck motor, and use all the parts of the marine engine

fuel pump
circulating water pump
intake
carb
starter
alterntor
distributor
ignition module

 

[hvymtl939]

If the head gasket blew the head probably warped a bit. So the heads get resurfaced and valves done, and for 200 to 250 your back up and running.

If you try a junk yard get a truck motor, and use all the parts of the marine engine

fuel pump
circulating water pump
intake
carb
starter
alterntor
distributor
ignition module

There's a local dude selling a 1997 vortec with 116k on it for $250....that might be the ticket.


Edit: Same guy also has heads for $30 a pop.

 

[achris]

Using a junk yard 4.3 will also require the head gaskets and core plugs to be changed.

Chris. ...

 

[alldodge]

Using a junk yard 4.3 will also require the head gaskets and core plugs to be changed.

Chris. ...

Normally yes, but not with what I'm hearing, they don't much care about longevity. Also don't know if its fresh or salt water

 

[hvymtl939]

Fresh water exclusively

 

[Rick Stephens]

Milkshake is just as, or more, likely a cracked block from poor or no winterizing, Before you ever assume that it's head gaskets, particularly with a freshwater cooled marine engine, pressure test the block to find out. Often head gaskets don't put all that much water into the oil. A cracked block will. Most common place to crack on a 4.3 is above the lifters in the galley under the intake. Block the lines going to the exhaust manifolds, pull the 'in' hose off the thermostat housing that comes from the transom, and pressurize at the thermostat housing.

 

[hvymtl939]

Milkshake is just as, or more, likely a cracked block from poor or no winterizing, Before you ever assume that it's head gaskets, particularly with a freshwater cooled marine engine, pressure test the block to find out. Often head gaskets don't put all that much water into the oil. A cracked block will. Most common place to crack on a 4.3 is above the lifters in the galley under the intake. Block the lines going to the exhaust manifolds, pull the 'in' hose off the thermostat housing that comes from the transom, and pressurize at the thermostat housing.

That's a good call, I'll check that out as well.

 

[Lou C]

I'd do a compression test, and change the oil a few times to get the water out (drain block after running). You could take it down to the block and have the heads checked by a machine shop. Make sure they check them for cracks. I had a bad overheat on my 4.3 some years back and it ran fine for 2 more seasons and then had water in #2 cyl and a bit in #1. Also water in the oil. Took it down to the block and found that the block was ok no cracks, not warped. Took the heads to the machine shop and they found cracks in both center cylinders, but ironically there was no water in those. Cooling ports were getting eroded by salt water use so the best plan was to install a set of re-man heads. So that's what I wound up doing....

 

[hvymtl939]

Just an update. Put the boat on craigslist for what we thought was a pretty high price. Figured if it sold cool, if not, we'll keep working on it. Well, first person to come Saturday morning took it home! Kinda bummed, but I have a million other projects, so glad it went to a good home.

 

[alldodge]

Thanks for the update