2013 Mercruiser 3.0 MPI (engine rebuild)

[Drool]

New to the forum!

I recently made the decision to buy a 2013 Tahoe q4i with the mercruiser 3.0 mpi. Bought it for cheap with a blown motor. Oil/water mix while out on the water, it was shut down and towed back to the dock. Ive done my research on these engines and it came down to 80% of people saying its caused from not being winterized properly and the block or head cracking. There for I will be tearing it down soon to rebuild and get ready for next summer.

My question for now is, is the 2013 mpi block interchangeable with a early 2000’s carbureted block? Asking because parts for this engine are hard to find.

 

[alldodge]

Yes heads and block are the same

 

[Scott Danforth]

Any 1991 and later block and heads will work

 

[Chris1956]

Why not consider installing a reman 4.3V6? Much better motor. You will likely need to rebuild the motor mounts, though.

 

[Drool]

Why not consider installing a reman 4.3V6? Much better motor. You will likely need to rebuild the motor mounts, though.

I would like to but not wanting to deal with the wiring side of the swap. Have you done this before? If so what are the cons while swapping

 

[Scott Danforth]

I would like to but not wanting to deal with the wiring side of the swap. Have you done this before? If so what are the cons while swapping

they all use the same 10 pin connector. the wiring is the easiest part of the swap.

 

[Scott06]

I would like to but not wanting to deal with the wiring side of the swap. Have you done this before? If so what are the cons while swapping

The con is making sure it fits and making sure you have all the pieces. As mentioned the engine harness connects to the boat harness via a 10 pin plug. You just need to have a 4.3 hareness.

By far the easiest way to do this is get a complete tear out so you have the wye pipe exhaust manifolds elbows etc, engine mounts etc.

Boat wise the biggest issue is will be if there is room in your engine compartment and if you have the side motor mount stringers. On my old boat I had considered a 3.0 to 4.3 swap but the boat when equipped with a 4.3 due to wider engine had a bench back seat with sunpad vs a doghouse with a seat on either side of it...

As mentioned any 91 and up one piece rear seal 3.0 block will work. If it was freeze cracked I would also consider the head and manifold suspect.

I think these guys regularly offer 3.0 blocks- not cheap but the 3.0 was never used in truck or automotive applications https://www.ebay.com/itm/263805256083?hash=item3d6c04c193:g:HFUAAOSw4SxbQ2lc