4.3 mpi screwed the pooch

[Josh28161]

My 04 280da had an engine die on me today. Port engine was running but a little rough. No warnings or alerts on the smartcraft. Ran on plane for a few minutes and when I came off plane it immediately died. Oil looked brand new before I left the dock. Opened the hatch and found a puddle of oil/water foam in the bilge, overflowed from the dipstick. Pulled the heads, water in 2 cylinders. Time for a new motor. I talked to the local shop and they told me 15-20k. I’m thinking I will just try to replace myself, but could use some suggestions on where to source a new/remanufactured motor from. The marina I use said they would help me with their forklift to pull the old motor and set the new one.

 

[Fill Ess]

MM has this (block/heads/etc) then you could move over all your current accessories:

https://www.michiganmotorz.com/4-3l-vortec-marine-engine-1996-current

 

[Pirate Lady]

15 20K, just no. Ask around.

 

[blaster]

Yeah thats new complete power package territory. Way high for a long block replacement unless the boat is a complete mess.

 

[Josh28161]

Thanks guys. Totally agree they were crazy high on price. Plus they said 6+ weeks before they would even look at it. I have since pulled the intake/exhaust manifolds and the heads. With all of that off I see how easy it is to pull the motor. I’ve ordered a short block from wholesale marine and my marina said they would use the botel forklift to help me remove and install. I’ll post how it went.

here is where I got the replacement block.
https://www.wholesalemarine.com/gm-4-3-marine-engines/

 

[Pirate Lady]

I have bought small stuff from them. They seem to be very reputable.

 

[Espos4]

Thanks guys. Totally agree they were crazy high on price. Plus they said 6+ weeks before they would even look at it. I have since pulled the intake/exhaust manifolds and the heads. With all of that off I see how easy it is to pull the motor. I’ve ordered a short block from wholesale marine and my marina said they would use the botel forklift to help me remove and install. I’ll post how it went.

here is where I got the replacement block.
https://www.wholesalemarine.com/gm-4-3-marine-engines/

You said “short block” in your post. You really should get a “long block” like the one pictured in your link.
Don’t re-use salt water heads on a new short block.

 

[KevinC]

Yes, definitely get the long block like @Espos4 said. If you had water intrusion who knows how messed up the heads are.

Your also probably going to need new manifolds risers and elbows as required.

-Kevin

 

[Josh28161]

You said “short block” in your post. You really should get a “long block” like the one pictured in your link.
Don’t re-use salt water heads on a new short block.

Thanks guys, you’re correct on the long block. That is what I meant and ordered. Complete with new timing cover, rocker cover, and oil pan already installed.

 

[Tacoma290]

Take a close look at the exhaust manifold, since it is possible that may have been the cause of your failure. You will already have things apart...

 

[Josh28161]

Take a close look at the exhaust manifold, since it is possible that may have been the cause of your failure. You will already have things apart...

I’m thinking it was a head or head gasket failure. Exhaust manifolds are only a year old. Mercury brand. They still looked new when I pulled them.

 

[Bill Curtis]

I’m thinking it was a head or head gasket failure. Exhaust manifolds are only a year old. Mercury brand. They still looked new when I pulled them.

I would test the manifolds just to make sure. Looking like new and cracked internally where it can't be seen is more common than some realize.

Don't want to hose a new long block on a bad manifold that wasn't tested. Testing for piece of mind here sounds prudent, even if a bad head / gasket is found.