Trouble with new Mercruiser 5.7 engine - anyone else?

Hi Everyone,

What I was really trying to do was poll the community to see whether my engine was an isolated failure. GM engines get imported to the UK in a number of ways by a number of different suppliers. No single supplier will ever know the full picture. If there are significant numbers of cylinder head failures for instance no single supplier will see the numbers. They may be oblivious to a widespread problem. The only way I can see if this is the case is to ask a question on all popular motor boat forums. Which is exactly what I have done.

Terry
 
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Hi Terry,

I read through your BOC thread last night and this evening and it does indeed make grim reading. I've certainly not heard of any others with anything similar myself and can see that it'll be very difficult to ascertain the original cause. My thoughts would centre on the broken trailer launch/submersion and in particular, if the vessel was any lower in the water as a result of ingress into the bilge - or even stern pushed in deeper when stuck on trailer supports? Even short-term could have thereby perhaps have allowed an amount of water to bypass the faulty/displaced flappers and get into the engine? Was the engine running during the launch? (Flappers may even not have been faulty at that time, but stern 'pulled' lower into the water when impaled on trailer perhaps?) A minor hydro-locking might not have been enough to stall the engine and could have been misconstrued as a misfire, but as water can't compress, something would have to give and to my mind this appears to have been h/g and head. I can't think the QC is so poor that head bolt torques weren't checked at the factory and yet you thought they were lightly tightened. That perhaps a consequence of the minor lock up/resultant head distortion? As you overhauled exhausts, gaskets etc pretty comprehensively, I'd suspect that the heads were cracked when you refitted - maybe not as much as now, but enough to result in the subsequent failure.

I had a h/g fail on an old Range Rover 3.9 and the garage that repaired didn't skim the block which was lightly scored between 1st pot and water channel - thus less than 10000 miles later, it failed again in the same place. The scoring amounted to no more than a scratch to the eye, but the amount of water lost and the steam cleaned bore astonished me! Due to personal circumstances at the time, I drove for perhaps 3000 miles before I could fix (carrying quite a bit of water and expansion cap loosened! I replaced with a composite gasket myself 2nd time and filled/polished the 'scratch' with a liquid metal. The car was reaching end-of-life at the time and I was skint - but engine was still going strong 40000 miles later when tin-worm did for the chassis! Point is, what can seem like a tiny crack can have far-reaching consequences with the heat and pressures involved - especially at high revs under load - as I'm sure you're aware.

I hope you can get a satisfactory outcome and get back on the water very soon, but fear that any recourse could best have been with the trailer incident and it's a shame that the issue wasn't more apparent at that time because I suspect that avenue may be closed by now? Budget-wise and based on what to do if supplier haven't resolved anything in the time-frame you've allowed, I'd probably go for the 2nd hand heads in Ireland and one more DIY assembly - applying all that you've leaned first time around. IMHO, you've then pretty much covered all bases other than a faulty inlet manifold - which presumably was supplied with engine?

How far are you from the boat? A local forumite might be able to offer some help either via loan/hire of a trailer or even a tow home? If nobody closer can assist, I would gladly help with the latter, but unfortunately don't have a trailer big enough for a 25' boat!

Good luck whatever course you take.

Robin
 
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Hi Terry,

I can't really offer much in the way of fault finding but when we bought our boat at the beginning of last year it was sold as having a faulty engine.. The sound similar to yours but MUCH louder and there was a distinct and loud knock every few revolutions (rather than every rotation) and if the revs were increasing to decreasing it was even worse.. The engine had already been replaced from the original Volvo Penta engine but I had no details about who did the work or where the engine came from.. We decided for peace of mind to replace the complete engine from carb to risers from Repower Marine rather than fix the faulty engine..

While we didn't bother stripping down the old engine to see what had happened the engineer that fitted the new engine said it looked like water had got into the engine some how, most likely through the risers or manifolds.. Since we were replacing them we didn't test them..

Has now covered around 25 hours on the new engine and so far all seems ok, hope it stays that way.. Following your story I will probably have a good listen next time we are out to make sure I can't hear anything even starting to sound wrong..
 
As part of my running in procedure I checked the oil before and after each run and kept a dated 'dipstick and blotting paper' record. That is one of the reasons I was astonished by the engine's sudden failure without any warning. I really don't understand how I could be more diligent than that. I went from a perfectly healthy engine to water ingress in 17-1/2hrs running (this is with the brand new engine - before I repaired it). There were no warning signs.

I would certainly recommend checking the oil before starting the engine every time you go out. Look for browning of the oil and any rise in oil level. Browning means moisture droplets suspended in the oil. Oil sits on water so any rise in oil level at all should prompt an evacuation of the oil. When you start pumping the oil out you will see emulsified oil which won't show up on the dipstick.

There hasn't been lots of reports of engine failures. So, I am tending back to my original presumption that I was just unlucky and/or I caused the fault myself. I did find two other instances of cracked heads. The cracks were identical to mine which is a little suspicious. But, 2 isolated incidents is probably within the realms of back luck. Not a manufacturing flaw. I don't know how many engines have been sold so I can't do a percentage.

The supplier, that you somehow guessed was Repower Marine have been really good to me and exceedingly patient. It is a real shame that their supplier "Marine Power US" have washed their hands of the matter. Lesson: Whenever you repower a boat engine you must never under any circumstances use existing engine parts however well they are tested. It provides an instant get out of jail free card. It is important to realise that even the most mundane part can definitely cause engine failure but will definitely void your warranty. I don't know where you draw the line here. Even your transom has an effect on the probability of water getting into the engine. Even the way you "drive" your boat can possibly cause water ingress from the transom and past the flappers. How much attention do you pay to your bow-wave catching up when you slow down? I do because I used to run a tiny rib but people don't consider the rise in pressure coming from the rear. Think about it . . . is there really any value in a warranty?
 
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rbcoomer said:
What was the final outcome of this Terry? Did you get back on the water for the summer?
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Hi,

Yes, I got her working by the end of the Summer 2014. It was a real trial and quite costly even doing it all myself. I had to invest in two new cylinder heads for the new engine as the old ones had both cracked. The engine survived water ingress (due to the cracks) and is well and now running like a new engine (well, it is a new engine so it should do).

Lessons learned:

1) There is never a warranty on new engines no matter what the paperwork may say. If the engine goes into a used boat there will be some part of the old installation to blame for the new engine failing e.g. exhaust cow-horns, boat sitting too low in the water. I have a huge list of "get outs" from my interchange with the UK and US suppliers. 90% of them are plausible in court. None of them were true. I got the Friday afternoon engine.
2) UK based suppliers of American kit cannot support you with a serious issue. The best of them may be willing to try but if the American supplier is unwilling to put their hand in their pocket you will get nowhere. UK suppliers have no sway over their supplier in the states because they simply do not buy enough kit from them due to our small and insignificant market.
3) Never rely on UK engineers. If you are really lucky enough to find a good one they will not have the time to spend on your problem. There is far more money in non-problematic jobs like servicing outdrives.

I wasted a hell of a lot of precious time trying to convince the supplier that I got the "duff" engine. I then spent ages trying to have it fixed (by the UK supplier who turned up once but just made promises after that). It was only when I bought all the special tools and did it myself that things began to move.

I am looking forward to my first full season with the engine this year. It served me well over the Winter. I had quite a few good cod fishing sessions. I still have a few fillets in the freezer.

Many thanks for asking.

Terry

PS I am on the Bayliner Owners Club forum all the time and I have never heard about another replacement GM engine with similar issues. I take it from that that I was just very unlucky. The engine supplier is still in business and cracking out the engines. So, I guess the corroborates the theory that these are fine engines (usually).
 
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Thanks for the update Terry - I was thinking about this at work the other day as I'm contemplating a 5.7 repower in the summer. Agree about the DIY - nothing like 'knowing' that it's all done right :) Great to hear you finally got some use too - let's hope this year offers up a great summer and you get to put it all behind you! It does sound like a very unlucky set of circumstances and great credit to you for the perseverance - I think a lot of folk would have taken up golf or hiking instead! :cool:
 
rbcoomer said:
Thanks for the update Terry - I was thinking about this at work the other day as I'm contemplating a 5.7 repower in the summer. Agree about the DIY - nothing like 'knowing' that it's all done right :) Great to hear you finally got some use too - let's hope this year offers up a great summer and you get to put it all behind you! It does sound like a very unlucky set of circumstances and great credit to you for the perseverance - I think a lot of folk would have taken up golf or hiking instead! :cool:
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Wish I knew of a safe 5.7 supplier to recommend. I work as a business analyst so I get to see businesses for what they are. I hope you will factor in your supplier's ability to put things right into your buying equation. I wouldn't say that I bought cheap but I didn't go "high end" either. I traded risk for price and came unstuck even though I paid middle price for the engine and had a professional installer.
 
I bought 2 x 5.7 full engine from Repower and fitted them myself last Spring - they included new everthing, I took nothing from the old engines except for brackets and some pipes. Ran them for 15hrs last season, faultless performance.

Was seriously let down by electrician, only job I farmed out - Joe at Repower came out to the marina and re-wired the engines for me (both coils had been blown by incorrect wiring) on a Saturday afternoon , fitted 2 new coils FOC! and got us running. My personal experience of Repower has been exemplary and i wouldnt hesitate to use them again.
 
The reason I started this thread was just to see whether I had an isolated incident or whether there is a plethora of disappointed engine owners. It looks like mine was an isolated incident and I am leaving it there.

If anyone out there is contemplating a new engine just be mindful. Usually, when you buy an imported item at that sort of cost there is a service infrastructure in place to pick up the pieces when a customer has an issue. When you buy an American boat engine from a UK supplier this is not the case. Buyer be aware of the limitations of UK support. Buy an engine for a John Deere (US) tractor and there are service-points throughout the UK. Buy a GM marine engine and there is no such back-up. You just have a willing but not excessively well funded shop-owner running around the country doing the best they can in between doing their day-job (running their shop).
 
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