Blown engine, ridiculous!

pstew96

pstew96

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Dec 4, 2003
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I just replaced this engine a year ago for 12K, all I was doing is crusing about 4K rpm for about 1/2 mile when a crackle noise came and the engine stalls, I go down and check the oil, was fine, no alarm sounded and the engine is hot(risers) shouldn't be so hot as they are newish and the outdrive was serviced along with the new engine. I tried to start the motor the next day, it started made some heavy metal sounds and stalled, My previous engine only had about 80 hours on it when it sent a connecting rod through the oil tank, that boat motor sat for long periods(boat is a 2004 Maxum) its getting so I'm afraid to get the boat up on plane for fear of blowing a motor! This is ridiculous!
 
What engine & drive? If you had a new engine installed last year is it still under warranty? You have no choice but to bring it to a mechanic but if it has a Mercruiser warranty maybe another shop could figure out why after only one year you have another problem.
 
What engine, what drive, was is it a rebuilt or new, by reputable shop or backyard shade tree guy, FWC or RWC, what w the temperature when the noise happened... Hard to suggest anything without coherent info

The most likely issue for sudden failure is picking up a blockage to raw water flow. Some engines don't have alarms and even if they do if RWC it s often too late
 
Was the problem causing the first engine to fail identified and corrected?
 
You haven't actually identified a problem yet.
 
My first engine a 5.0 was sitting alot, 2004 Maxum and only accumulated 60 hours in 12 years, but, the first year I had it, I put on about 70 hours so the sitting didn't seem to affect it to much, then the next season it threw a connecting rod, why I don't know, the oil and cooling were fine. So for a replacement engine at $12K I opted for a 5.7 300HP Alpha motor. My alarm which detects Heat/Oil/Outdrive lub didn't go off and the holes for cooling were not all clogged with barnicles, a few were.I do recall bringing the outdrive up to high for a second as the trim is very slight. I could hear it rev a little high for a second. I only traveled about 1/2 mile at high speed to get on plane.
The warranty ran out a few weeks ago!
 
Was this a new crate motor, short block or long block, or remanufactured? What was the recommended W.O.T rpms for the engine?
 
Crated short block, 4600 to 5000 RPM at WOT.

MERCRUISER PLUS SERIES 350 MAGNUM MPI ALPHA ENGINE 300 HP,

West Marine Synthetic Blend 25W-40, NMMA Certified FC-W Synthetic Blend which had maybe 40 hours on it!

Just got on plane, then bam!
 
Still waiting for the cause of the first engine. Any cause on the new engine yet?

What drive?...different water pumps.

What is it you want help with? Or are you just complaining.
 
If that's a "Plus" series engine, it's a complete "bobtail" Engine, Vortec heads, MerC-made intake manifold, full fuel system (MPI in this case), "tin" (oil pan, valve covers, front cover), power steering pump, circ pump, alternator, serp belt, starter, full exhaust, wiring harness, coupler. They are sold as Re-manufactured because they're based on a "pre-owned" (whatever that means, unclear to me) BLOCK.

We had a Plus installed in our Sea Ray. It's the "Alpha 4V" at 275-HP also known as a "357" because it's a 5.7/350 bored 0.040" over.

When GVP was here, he didn't like selling reman engines because of re-use of parts, and one of those parts was likely the cause of failure in the first engine. Said engines don't usually go out on simply age and wear. Something kills them, and if that something goes on the new engine it kills it. Then the customer wants another engine under warranty...
 
So, it turns out not to be an engine issue, but a gear in the Alpha 2 drive, the top most gear just shredded and the metal rained all over the bearings. Stopped the engine dead though. So I suppose I just have to spend about 5 grand to have the whole drive replaced....
 
"and the outdrive was serviced along with the new engine."

Who serviced the outdrive and did they mention anything about metal or problems?
Was the drive lacking lube?
 
An Alpha drive has max HP capacity of 300. Our Alpha was wasted away in the internal water passages. The lower went first, and I got one from SEI. Then the upper, another SEI. Not sure I'd go that way again. Maybe SEI castings and re-use the MerC internals. The upper in our SEI ate a bearing and SEI repaired it under warranty. Three years unconditional. They are NOT as corrosion resistant as MerC, and their gears are not as quiet. The failure in our upper gearcase did not make enough metal shavings to contaminate the lower. You'll have to make sure your failure didn't either. I'd think a gearcase could be flushed with a solvent and see what comes out. The lower drain plug is magnetic, so that'd be the first place to check. Most of the shrapnel is probably still in the Upper. If you repair or replace the Upper, you'll probably eliminate most of the trash. Bravo's circulate the lube between Lower and Upper. In Alpha's the two are linked mostly to be able to fill and drain from one source.

See if you can get a look at those upper gears. You can hide one in your hand. Very small for 300 HP.

But I AM GLAD it isn't the Plus Engine!
 
Yes j-d, they are small and I did have it serviced last July. I think part of the problem is that the boat sat allot, it had 60 hours on it when I got it, I put about 70 hours on it the first season before the engine blew, I would have expected something to have happened shortly after the 60 hours, not so far after...
 
After ours tore up, I added a Drive Shower. Mine is from SEI but there are others. As I mentioned, there are water passages in that upper gear case, but a shower unit supposedly helps. Remember, the LOWER is in the water on plane, the UPPER is not, and Alpha's oil doesn't circulate to get cooled like Bravo.

Be sure to use MerC's super lube. I forget what it's called but I have some and can tell you. It's full synthetic and green. Their "premium" is still dino oil. Better change it often. Ours went black in 100 hours.

I lick my chops thinking what that 300-HP 5.7 does pushing your boat! We had a 220-HP 5.7 and this 275 has far more power. Can't imagine the jump from a 5.0 to your MPI 5.7 dragon. You must have had to change propellers. What did you go from and to? What's your gear case ratio? Should be stamped on the Upper.
 
Drives can't just be flushed successfully. These are open bearings and gears. All the little particles get in everything. I won't go into a rant about marine repair 'TECH's, suffice to say I do all my drive work myself. Just get an aftermarket drive. They're cheap enuff that you can buy 3 in place of one merc unit...though I haven't priced a merc drive in a couple decades.
 
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