496ho shutting off
 

bought this boat a couple months ago from Texas 2004 outlaw 25 with 496ho that says 130 hours. Something is wrong with the boat I bought. Motor doesn't sound right, almost sounds like gravel in the engine. Took it out today and ran it hard for about 15seconds and slowed down and then when I went to take off again boat shut off and I had to limp it back to home with least amount of throttle otherwise boat would shut off again. Opened up engine bay and smelled hot and coolant was at top of reservoir.

Any ideas, it has been a headache ever since I bought this boat will never buy used again

Sorry, not enough info here. Everything we could say would be swag. Start with the basics.

Is it beeping/alarming?

What more info would you like?


No beeps or alarms

What temperature gauges do you have? Water? Oil? What temps are they reading when have it running after a few minutes?

Also, the coolant in a 496HO is only good for 7 year or so TOPS, regardless of hours. If you do not have record that it has been changed, it likely needs to be. If it is not BRIGHT pink, it's bad. If it is darker and metallic in color, it's silting up and not flowing/cooling well. This doesn't sound like the only thing you have wrong, but could be a starting point.

Can you get a video of it running? I don't know what gravel in a motor sounds like; as I've never experienced that condition.
Has it ALWAYS had this noise? At what RPMs? If so, this noise you hear may just be your internal flappers inside the exhaust tips.

Only temp gauge I have is water temp and reads right in the middle after warm up.

The coolant is a darker red color and when motor kept shutting off it was coming out of the cap in small amounts.

I also think the ticking I hear is in the exhaust but just trying to give as much info as possible.

This is my first off shore style boat

Just put a brand new 26p bravo 1 on it and it only gets 4600 rpms at 62mph on gps but I feel under low rpms there is vibrating but again maybe that is just normal

Also should note it has cmi headers, corsa captains call, and whipple ecm tune

I would recommend finding a mechanic in your area that is familiar with the 496ho and have the motor scanned. It sounds as if you are having a cooling issue. I know you said the water temp gauge is right in the middle but that doesn't help any of us dignoise your issues we need to know the tempature. You should never have antifreeze bubble out of the overflow tank.

Here are all the guesses that I can come up with.

Overheating
Your seawater pump is bad not working properly. Most likely
You have a restriction in you raw water side of the cooling system (heat exchanger tubes clogged maybe)

Rough Running

Probably needs a new set of spark plugs, not sure which ones you need with the ECM tune.
Could use a new set of spark plug wires
Bad Fuel
Needs fuel filters depending on S/N could be a few different types
Fuel injectors could be clogged up if you have a gen III cool fuel system the paint inside the cooler could have flaked off and clogged your fuel rails/injectors.

Lack of RPM
Most likely the engine is in Guardian mode protecting itself from other adverse conditions reducing your available power. Overheat, IAC Fault issue

These are all issues a good mechanic that understands the 496HO should be able to pick out with a scan.

anti freeze darken is from overheat as well. Where in Texas did you buy the boat and from whom ? This app is not stock so to pinpoint anything without ears, eyes , hands, scan and testing tools one is throwing huge darts with a small dart board period. Your location is ?

Buying a hopped up 496 in most cases is not a good choice because many whom think they and or can be done, only ends up being a huge headache period. Also sounds like you did not get a survey and mechanical inspection done. Totally bad move on any buyers part. There is more crap used boats on the market than good mechanical boats for many reasons.

the engine is guardian mode and or not running on all cylinders - start with basics. Fuel samples, fuel pressure testing, spark testing, compression and leak down testing. Examine spark plugs and run on a portable fuel system and scan the engine.

My guess would be voltage / and or water pressure / overheat issues / and possible exhaust manifold overheat for the shut down. Again a left field guess. Just because you have no alarms means nothing period and whom even knows if you have a working alarm or one that works. So lets ask from the start - If you turn key to run position NO ENGINE Start -- do you hear the self test beep (alarm) ?

Also without an alarm hooked or inactive does one know that will set fault codes and could be one of the problems and in some cases engine shutdown ? This pertains to ecm 555 and Pcm 555 and up ---- marine computer controlled engines Mercruiser side of the coin among other engine manu's as well.

CMI headers - what was done with and or to the exhaust overheat / overtemp sensors ? One can not just unplug them or leave them out with the ecm / pcm 555 -- that parameter is in the mix (stock tune ) or even recal tune. Are they incorporated still in the mix ? Or were they turned off by the reprogrammer of the PCM ?

Do you even have an PCM 555 computer installed for this 496 app ?

Bought he boat without much research my entire bad fault. To good of deals usually end up this way. When I turn my key no I don't hear any noise or beep.

Side not my voltage has been low since this happened.

Just took it to one of the most reputable merc mechanics in Wisconsin right out of Oshkosh dropped it off and told them everything that I have wrong.

I bought the boat off of power boat listings from a small town in Texas north east of Dallas will post a picture to see if anyone recognizes it.

99% sure there was a charger on the engine before I bought it but seller said no. Also it is a 2004 and it was advertised with 200 hours on engine and that is what meter says in engine bay but will have the mechanic scan the engine to check it out.



Side note, if I find there is actually a **** ton of hours on the engine woukd you think there is legal evidence of him having to help pay for some of the repairs?

Trim tabs do not work, trim barely works as of last week, just a headache, depressing first buy and realize it is my fault for not having it professionally looked over

Also for guy asking about cmi headers I did not install them they came with boat but I did out corsa captains call on it not sure what he did with sensors. He told me he sent the ecm to whipple to have it tuned

You are only a few miles from me, I am not sure who would be reputable around this area. I will help you figure this out if I have to fix it myself.

Post the engine serial number (it is ok to do that we can't do anything with it).

BUP who responded on here is one the best 496HO problem solvers in the country. Because of where you bought the boat there is a chance he may have worked on it and the previous owner did not want to fix per his recomndations. I tell you listen to him.

If the CMIs were order for the 496. They have the temp bung installed.

The above plus engine shutting off / running like crap, sure sounds like a voltage issue to me. Before digging into wiring, please question your battery (s) and alternator.

I actually live in oconomowoc I am haveing Riggs marine service look at the boat out of Oshkosh is that who you were thinking of?

Also I do not have serial number of engine as it is there right now.

I will upload a photo right now of boat to see if anyone recognizes it


There is 4 batteries on the boat to upkeep with sound system but possibly alternator isn't doing its job.

Your biggest wild card right now is that ECM tune. I would email Whipple with the ECM s/n and ask them nicely if it was tuned for charger or not. If it was tuned for a charger and you do not have one it will never run right.
As much as it pains me, because it's not cheap, I would recommend getting it tuned back to stock. Most mechanics are only going to know what things are supposed to be, not what they should be with the tune. I would not be shocked if you are told to get a new ECM. Most of the guys around here are good, but they are glorified parts changers and not so much on the diagnoses side. That does not make them bad, its just most fixes are pretty simple. Unfortunately, you have what I believe to be multiple issues going on. In addition, depending on who has your boat it may be awhile before you see it again, this is a very busy time of year for these guys. I can tell you stories about all of them.
If they say you need a water pump get the harden marine one. It is better for the 496ho application in the water that we boat. Sand silt eats up the brass pumps kind of fast.
Riggs is good this is not their forte, think carburetors.

Here is the boat I boat I bought if anyone recognizes it

https://imgur.com/gallery/QC6mt


Questofpower thanks a ton for the info I will be giving you a call after Riggs calls me and tells me what they think the issue is and I will run it by you

Sounds good

Also expect that call in about 3-6 weeks.

Should the guys at Riggs know that the ecm was flashed by whipple when they scan the engine

Anyone have a ballpark what I'm looking at spending to fix this money pit

Thanks for the good words first and foremost.

I want to add I have never ever touched this boat nor seen this boat ever - and the reasons I want to post this is 1. I do not want my name associated in any form linked to a problem child like this --- The deal with me would have been, if the boat was in my hands whenever timeframe(s) - I would have either passed on touching it or the boat would have left my hands without one single issue being 100 percent turn key lake tested and lake ready., I very much so wanted to post this to make sure my name was never on this boat period. Sorry for being so adamant about this here. Hopefully not sounding like a pita either.

4 batteries and all hooked to what and where and why ??? Also sounds like a wiring mess in the making as well

I did list voltage as an issue, all ECM's / PCM's hate low voltage and unsteady voltage. They need proper voltage and steady voltage constantly.

How many accessories are spiced into any of the wiring harnesses here ? a complete not to have anything sliced into a computer control engine - any inline splicing of whatever added into the mix can cause voltage problems hugely . Just saying

No way to know without knoing the issue.

That said, diagnostics costs money and who know's how long and how much you will be charged for this part of the repair.

Good news - you can put a $$$ amt of diagnostics not to exceed without contacting you and getting further authorization if need be. And yes, you can get this in writing. I've done this a bunch of times for customers......many (not all) are low blue collar and low income and schit bricks over $50 let a lone a few hundred. This puts them at ease and it mostly makes sure I don't waste my time ($$$) also.

Man that would like picking the score and the winner in the 2018 super bowl. no offense but does anyone know whats wrong and all the issues yet 100 percent all of it ?

Hey everyone again I say thank you for all of the info not the kind of guy to get into a legal mess with anyone, wisconsin breed through and through just honestly want to fix my boat.

BUP,

There is 1 battery for starting and there are 3 others to run 12 speakers, 3 wetsound subwoofers, and two amps. There is also led lighting around the speakers and there is led lights out the transom.

Other then that there is nothing out of the ordinary for electrical

Also forgot to add would anyone know why when I lift the back seat why a huge 2x2 foot would be cut from the engine bay into the seat through the fiberglass ? Again I'm assuming blower?

Could it be the starting battery is isolated from the others,,,,,and the starting battery is used only for cranking. Hmmmm. Everything else is on a dead battery(s) or one's not being charged at the moment.

So, as Bup mentioned, and I mentioned in quotes below, let's get looking at the batteries, switches, and alternator first.

Yes, I did near the same (in my case about 10" x 10" or smaller) installing a Procharger, The intercooler (factory position - I couldn't really put it anuwhere else anyay) needed more room. :)

I missed what I bolded and underlined in red above,

Get to it !

Then I'm assuming he ripped off charger and sold boat to me with charger tune on it and just said screw you. Fun fun ready to ghost ride this thing over a damn

Sorry BUP I didn't mean to imply that, I know that's not what your saying, you just want to make sure you name is clear of it. Only thought it was a possibility due to the proximity. The boat is in decent hands now we will keep you guys updated with what we find out.

OP is struggling a little with the questions mainly because he does not know what normal is. One thing that is interesting is no recollection of hearing the fuel pump after the key is turned. I would have to hear it to know for sure. We are going to let them see what they find and go from there.

100% never heard fuel pump or beep when key was turned. I have been boating my entire life, live out on a lake out here and parents have had tons of boats. How I made such a bad decision on my first purchase blows my mind


Saw a boat I have always wanted and didn't think before I bought. Live and learn

I never even thought about it till now how always when I started my parents boats you always heard the fuel pump and a siren/beep.


Again thank you all for all of the information I will be forwarding a lot of the info to the mechanic working on it just incase he misses something

Don't beat yourself up too bad. We all talk all wise and smart on here. But I have list a mile long of dumb $h*t that I have done and I am guessing everyone that has posted here has one too. My list is still growing. Just last year I let my wife tell me when the power steering pump reservoir was going low while trying to bleed out a new hydraulic steering system (I knew better). I know that if you let the smoke out of electronics that is bad, apparently, if you let the smoke out of a power steering pump that is bad too. After, cracking the lines at the back just a little I ran to the side she says its empty and starting to smoke. What the )(*(*.

It is really my fault I never told hear exactly what to do. She says I was waiting for you to come back over here because I know you would not have heard me at the back of the boat. Anyway only cost me a few hours and power steering pump could have been worse. I could have went to jail.

Sorry to hear about you issue. I just sold a 2005 Baja 30 Outlaw. Over the years we had a few 496HO gremlins also. That being said, I have a spare 496HO PCM that I purchased used. The computer was not my issue. It was a water pressure switch. I live in Souther WI. Please contact me if I can help.

Just wanted to update as I now found out what is all wrong. Who ever had the boat before I bought it wired all 4 batteries in series with way to small of wire and melted all the wires and relays into the engine. Alternator was also shot from him doing this. So glad it was all an electrical issue. They also replaced all fluids, gaskets, and scanned computer for anything else wrong. Get to pick it up Tuesday

They said it was running in guardian mode at 85% when they looked on computer which I am glad becaus I could only get 63mph at 4600rpms on a bravo 1 26p

HMMMM pretty much a sums of all it right here and Like I say always read available power % per scan.

Any idea what I should be seeing for top end?

496ho all new fluids
190 hours
Cmi headers
Whipple tune

Have 24p bravo 1, 26bravo 1, 25p mirage plus, 29p bravo 1 with vents

4 batteries in SERIES? That would mean your system was running at 48 Volts; which would've had you fully engulfed a long time ago.