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4.3L Merc Compression problems

1

1marc1

Contributing Member
Hey posted on here previously regarding my 4.3L. Im still battling to figure out what is wrong. This problem happened almost instantly on the water when the boat went from running great, to barely running at all. And all happened when i may or may not of free wheeled out of the water. I hit a fairly large wave, felt as if we may of left the water and as soon as we hit back down i shut off the boat instantly and then as soon as i went to start it, it barely would run. Wouldn't want to idle in water and was a complete dog out of the hole.

Took it to a local boat shop where i was completely ripped off. They instructed me it was a fuel issue and my entire cool fuel system was shot. 1700 dollars later, they informed me my boat is still running the same and that i have no compression on cylinders 2 and 5. So regardless to say i raised sh*t got some of my money back and pulled my boat out of there. After i got it home, I tore one side of the engine down revealing the number 5 cylinder where there is a visible sign of some scarring but nothing i would call severe enough to give me zero compression. You can run your finger nail along the side wall and can barely feel anything. The head looks alright, i did a leak test and springs, rods, rockers are all straight and in good shape. But you can also see that my valve on the port are extremely clean on the Zero compression cylinder.

Any suggestions?? Gaskets? Or something within the head? Light a match and walk away??

IMG_3990.jpgIMG_3991.jpgIMG_3992.jpg
 
Did you verify the compression before head removal? What did the head gasket show...any leakage between cylinders? The extremely clean cylinder and valves may be from water intrusion. Are the exhaust shutters intact?
 
No i didn't. That is one thing i wish i done before i started taking it apart. But on their work order it shows they did do a compression check on both sides 3 times. And they did do wet and dry tests, every test on both continued to show a zero compression. The gaskets looked fine i thought, and the exhaust shutters are intact but whether or not they were working properly is another thing. I don't know to much about marine engines so, im not to sure if these shutter valves can fail or what?
 
Zero compression is typically from burned valves, blown head gasket, severely worn rings or warped head. The 1st pic. shows some scoring on the cylinder wall. You have zero compression on #2 and #5...one bad cylinder on each bank. The head gasket doesn't look damaged. If it was my engine I wouldn't waste any more time or money on this engine...buy a reman. longblock and not a rebuilt one.

You could try to find a salvaged running engine removed from a hull damaged boat or an engine removed for a power upgrade from a reliable source. Note that there were thousands of boats submerged in the storm last fall and many of the engines that ingested saltwater will be replaced...some unscrupulous SOBs will be selling them to anyone who will buy them. Be careful what you buy.

If money is not an issue then consider a new complete drop-in packaged engine...plug in and play. Just my opinion. Before buying an engine make sure the hull, stringers and transom are still solid and not full of rot.
 
Ok, i was thinking of just doing that anyway. I've blown too much time, money and energy trying to figure out why and what caused this and how to fix it. For the amount that i spent at the local marine place in the unecessary repairs they did that could of paid off half the amount it costs for a good reman long block. My boat only has about 150 hours on it and its all fresh water. And i Found a long block at Michigan Motorz.

Thanks for your time!
 
1marc1 said:
I hit a fairly large wave, felt as if we may of left the water and as soon as we hit back down i shut off the boat instantly and then as soon as i went to start it, it barely would run. Wouldn't want to idle in water and was a complete dog out of the hole.
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I'm going to suggest that when you backed off on the throttle and immediately shut the engine down, the engine underwent water reversion, such as what a few of the guys have mentioned...... and very likely from wave surge.
Water against hot exhaust valves is not a good combination. :mad:

Your low cylinder pressure readings are likely from warped valves, not necessarily burned valves since this resulted from this one incident.
While not always 100% effective, keep your back-flow prevention flappers in Tip Top condition.


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Perhaps a bit late..... but in the future, ask for and pay for diagnostics up front, and diagnostics that actually identify the problem. Then ask for a "quote" (not an "estimate") that fully describes the work scope that will indeed correct the problem.

By asking for diagnostics and a true "quote", this holds the shop's feet to the fire, in that if the work scope does NOT correct the problem, it's on their dime, NOT yours.
Otherwise, you may as well sign a blank check over to them, let them continue throwing labor and parts at it (at your expense), and you will eventually get it repaired.

Question:
Was the shop given all of this information above? (I.E., the fairly large wave and the immediate shut down, etc.)

If so, this should have given them an initial direction to trouble-shoot from.
Again, if so, you may want to complain about the work scope not correcting the problem, and perhaps attempt to negotiate with them on this.
IMO, that's a poor business practice on their behalf, and an injustice to you.... their customer.



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The manifold is original. Boat is a 2003 and always used in fresh water. And yes that makes total sense, because as soon as the boat went a little squirrely i threw back the throttle really fast and shut it down. As for the shop, i did indeed give them the whole story of what happened and how the boat is currently running. I also did get money back from them after their repairs because much like you said they done NO trouble shooting what so ever. I assumed they did when they told me my fuel system was shot. Figured they checked fuel pressure etc etc because it was smoking heavily do to like over fueling. But again if anything thought it would just been a regulator problem not the entire fuel system. But putting to much trust in what i thought were "professionals" cost me dearly. After seeing the work order and seen that they didnt do ANY troubleshooting at all i raised hell and took the issue straight to the owner and got half my money back. Told them i didnt bring my boat in here to have the fuel system replaced. I said they were supposed to find the problem and fix it........you cant find anything out without trouble shooting and replacing parts without doing so should not fall on my shoulders. It takes 20 minutes to check fuel pressure to see if my fuel system was shot and they didnt even do that. They started it, seen how it was smoking and that was their extent of diagnosing. Regardless to say........never going back and sharing my experiance with that shop to everyone. I live in a small community so word spreads quick.
 
Marc, me in blue text.

1marc1 said:
As for the shop, i did indeed give them the whole story of what happened and how the boat is currently running.
Good! That offered them criteria that they needed!

I also did get money back from them after their repairs because much like you said they done NO trouble shooting what so ever.
Excellent! Apparently they stepped up to the plate! :D


I assumed they did when they told me my fuel system was shot. Figured they checked fuel pressure etc etc because it was smoking heavily do to like over fueling.
Possibly two unrelated issues.
IMO, their primary focus should have been the immediate shut-down and the following problem that you described to them.

But again if anything thought it would just been a regulator problem not the entire fuel system. But putting to much trust in what i thought were "professionals" cost me dearly. After seeing the work order and seen that they didnt do ANY troubleshooting at all i raised hell and took the issue straight to the owner and got half my money back.
Ah... only half of your money?????? .... hmmm.


Told them i didnt bring my boat in here to have the fuel system replaced. I said they were supposed to find the problem and fix it........you cant find anything out without trouble shooting and replacing parts without doing so should not fall on my shoulders. It takes 20 minutes to check fuel pressure to see if my fuel system was shot and they didnt even do that. They started it, seen how it was smoking and that was their extent of diagnosing. Regardless to say........never going back and sharing my experiance with that shop to everyone. I live in a small community so word spreads quick.
If you file a report, and if you key-word it correctly, others will find it while checking this shop's performance record.

Some businesses are savvy to complaints found via search engines. They will key-word their own web site to include words such as "no complaints" or "we resolve all complaints" etc, etc, so that the search engines will pick up on these key-words prior to any actual customer complaint key-words.
IOW, they beat ya to the punch line.... so to speak!

Do a search..... you'll see what I mean.
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Yeah half my money unfortunately. I still walked away with an entirely new cool fuel system (even tho i didnt need it) they offered to replace it and put the old one back on for even more of a refund and i declined that offer. I didnt want them touching my boat anymore than what they have. But i went in there prepared and got what i wanted. I threatened to take them to the better business bureau, i had my lawyer write me a few sentences on business ethics and so on........and also informed them that if i dont get what i want its going to court. So i paid for the fuel system at their cost and pretty much everything else was refunded.
 
This is their actual write up. And is why i actually took my boat there to begin with. They received an A+ rating by the Better Business Bureau. Not sure how they got this rating but looked on BBB's website and its proven. My cousin also had his boat there aroud the same time......same story with him too. They swapped out his entire fuel system on his 5.0L set him back 2400.00 and left him with a boat that ran no different again. He chose to pay them and do nothing about it tho!? I bleeped out a few of the words.

Serving ****** and Southern ******* for over 15 years, ******** Marine has the strongest record of Customer Satisfaction in the industry, with the awards to prove it! Ranked in the Top 100 of almost 5,000 boat dealers in North America for 3-years running, we have won the ********* BBB "Torch" Award for ethics and integrity in Business and the ****** Chamber of Commerce "Paragon" Award for Continued Excellence in Customer Service (we're proud to have been nominated for these awards by our happy customers)!


We have a complete staff of factory-trained and certified service technicians, the best boat "bodyshop" in the prairies, in-house prop & skeg repair, acres of off-season storage, as well as the best selection of recreational family boats and watersports accessories in the province! All of this is backed by our friendly and knowledgeable staff whose #1 goal is your complete satisfaction!
 
Well, sounds like your cup is half full, not half empty.... good attitude! :D

There's a lesson in this for all of us.

The shop: Hopefully this has opened their eyes in that they'll do a more full diagnostics in the future, and not just simply spend their customer's money haphazardly.
And that they'll know that there are "Marc's" out there in the world, and that these "Marc's" won't put up with this! :mad:

You: The value of full and proper diagnostics in the future.

Us... the onlookers: We'll use your story and will take heed of your experience!



Now.... about that engine.
Since it did not over-heat, there's a chance that you could save it.
Perhaps with a cylinder head over-haul.

As for the block..... I can't really see from the photos if the cylinder walls are scored.
A good machine shop should be able to look at this and give you an evaluation.
If need be, they'll be able over-haul this and bring new life into it.

MichiganMotors does have a good reputation. I'd use them if you were to purchase a long block.




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I just now saw your post #12.

I'm of the belief that is a shop is not up to snuff with customer service, we should make mention of it so that others can see it.
Before doing so here on MarineEngines.com, you may want to ask James or Andrew if they would object to this.
If no objections..... post the shop's name in your thread here.

This may be a non-busy time of year for some shops, and in a frenzy to drum up work to keep the crew busy, they may perhaps exaggerate work scopes.
I'm not accusing... just stating a possibility.


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K, thats good to hear. I actually purchased a new long block just yesterday from their site. I will most likely rebuild my current engine once i have the time to do so. Either to sell, or for a back up. I cant remember if their long blocks come with manifolds but from the advice you guys have been giving me, i would say investing in a new set of shutters would be a good idea too!?

Thanks again for the help!
 
This whole ordeal with the shop started at the end of August 2012. This shop is so "busy" apparently that my boat went in for its "trouble shooting" probably 5 weeks after dropping it off and then didnt go back in to their shop for the repairs till November. We had to pull it back home in a snow storm.

And thats ok. Im a full time resident at the nearest lake to the city where my boat had been repaired. So not only do all my neighbors owns boats, but everyone from that city comes here to boat.........so word of mouth around here will do me justice!
 
Since they have low hours have the exhaust mans., elbows and risers cleaned and pressure tested at a radiator shop. Otherwise replace them w/Osco or Barr manifolds. If you want Merc. mans. make sure you don't get their cheapies.
 
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