How Much is it Gunna Cost to Re-build an Engine?

Jack380AC

Member
Jan 28, 2008
877
West Chester, PA / North East, MD
Boat Info
2000 380 Aft Cabin
Engines
Twin 454 Mag MPI Horizon MerCruiser
This is the thread we all hope we never need to post. But unfortunately, my mechanic tells me the rings are bad and a rebuild is in order. Ouch!:smt089

So how much do I need to save?

Anybody want to buy a Harley?
 
The more work you do the cheaper it will be. If you can get it out and take it to the rebuilder that saves on the labor they have to do.

Did you do compression test? how does he know its the rings?
 
Jack
Sorry to hear that. It's gotta be a beetch to get an engine out of an AC. Cost is a tough question to answer. Labor has got to be 30 hours. You can probably get a reman block for $3500 +/-, heads can be redone if there's no cracks - figure $500-600 for that. Then do you get involved with the "while we're at it?" ie: manifolds, elobows/risers. If you can pull the exhaust system and the heads yourself you'll save a good chunk of change in terms of labor time. If you're just writing a check, I'd think $6-7 boat dollars (??)
 
The more work you do the cheaper it will be. If you can get it out and take it to the rebuilder that saves on the labor they have to do.

Did you do compression test? how does he know its the rings?

Rick (owner) from Seven Seas Marine did compression tests and some other tests as well. I'm capable but not a motor head so I am at a disadvantage.

Compression readings were all over the place.
 
Jack
Sorry to hear that. It's gotta be a beetch to get an engine out of an AC. Cost is a tough question to answer. Labor has got to be 30 hours. You can probably get a reman block for $3500 +/-, heads can be redone if there's no cracks - figure $500-600 for that. Then do you get involved with the "while we're at it?" ie: manifolds, elobows/risers. If you can pull the exhaust system and the heads yourself you'll save a good chunk of change in terms of labor time. If you're just writing a check, I'd think $6-7 boat dollars (??)

Thanks. At least this gives me a pain threshold. I was actually thinking it would be worse.

Yes, they tell me they need to disassemble it in the cabin and reasemble after re-build. This has to add hour$.
 
Is it running poorly? Using oil? Spewing blew smoke on acceleration?

Unless there is something else going on, I would say that ring failure is a pretty rare cause for a rebuild these days. Perhaps if it got hot enough it could stress the rings and either crack them or take the spring out of them.

Did he do a "wet" compression test as well (squirt oil in the cylinders)? And if so, were those readings similar (bad) or normal? Ring failure will normally show good compression on a wet test.
 
Can't imagine how the mechanic could tell it wasn't the valves causing the low compression... I would get a second opinion before you pull you engine out... You can buy a compression test kit at Harbor Freight for $30 and check it yourself... If it was the rings, the compression should be consistently low, not all over the place... Plus, you should have the same problem on the other engine...
 
Jeff,

Not sure about your questions as to what tests he actually did. He went to the boat twice.

Original symptoms are that gradually over the last 2 to 3 years the starboard engine could not keep up with port. Now can't get both over 3200rpm. Boat won't plane.
 
Seems way too early for that major of a repair. Unless the oil was never changed and it was always run hard? Definitely a second opinion with NO mention of what the first guy is telling you.
 
I agree, pretty early for that repair, unless something happened to cause it. I'd get another opinion. Especially before I dropped that kind of cash.
 
Just replaced one engine. Rebuild was $1975 and a new engine was $2700. Easy decision.. went with new Chevy 350 in the crate. Ordered on Monday and was delivered to my marina on Wed. AM. Call Marine Engines at 800-786-7639. My mistake was having them pull the heads and have them evaluated etc. this used up valuable time and money. Get the gasket kit for $50 and total freight charge was $119. Very happy with the new engine and just completed a 150 mile trip on the Chesapeake bay
 
Unless u do the rebuild yourself, just buy a new longblock. I honk it would be cheaper and you an get a warranty too. Check out rebuilt.com, us engines, or Carolina machine.
 
I would really get a second opinion before I did anything. I'm sure there are lots of good options available - if the engines need replacement. But you should figure that part out first.
 
Thank the good Lord you do not have diesels. I had to have my 3196 CATs rebuilt in 2008 after ~740 hours per. It was about ~$40K plus another ~$8K for getting them in, out, and transported on a flatbed back and forth.

I got new heads for the rebuild. The stock 1997 heads showed 14 microscopic cracks when Magnafluxed (ECM showed she had been run hot at ~200 hours). The blocks, cranks, and piston arms were all kept as they were good to go. New rings, sleeves, etc etc...

It was a crippling expense, but she runs like a top now. Opened her up on flat water to WOT on Sunday and hit 31 knots with the tabs up.
 
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