2011 6.2L Mag Keep getting alarm mostly at idle

[skyman2112]

Hi group. im having water pressure problems in a 2011 Crownline with 6.2L Bravo one setup. Ive replaced the raw water pump housing with a hardin marine stainless one, new impeller, and new water pressure switch. Still get single beep alarm, and one time guardian kicked in at cruise and i dropped to an idle. The dealer says the pressure is reading low at idle and cruise. Checked the hoses no kinks, water flow seems good at the thermostat housing, runs cool never gets hot. Any suggestions??
The original impeller lasted about 2 years before I started getting the alarm, when i had it replaced they said the housing was getting pretty deep grooves in it so the next time the impeller went bad i would need a new housing. That lasted about 1 year and again the alarm. So i assumed the housing was finally worn and replaced the whole pump with the stainless aftermarket one and another new impeller, even though the one i took out of the old pump looked fine.. That lasted about 3 weeks before i got the alarm again. Im at my wits end here its the middle of summer and I don't have a reliable boat to drive. Thanks for any advice!

 

[Volphin]

What does your water intake look like? Any blockages?

 

[muc]

Could be many things causing this. What did the dealer suggest when they told you pressure was low?

 

[skyman2112]

When I pull the plug on the thermostat housing I have tons of water flow. The dealer suggested changing the water pressure sender. It hasn't given an alarm lately but I never know when it will happen. Im just waiting to see if it keeps happening. They dealer wanted to replace my stainless pump with the stock one but I said no thanks. Im sure there is nothing wrong with this one. So im still up in the air. I need to bypass the stupid switch cause it never runs hot and the alarm is putting me in guardian mode 1 time when I was at cruise. Very annoying

 

[alldodge]

Agree don't change your stainless pump housing, the dealer is either not to bright or just wanting to make some more money.

The pressure switches seam to have a lot of trouble with them over time. There is a thread here which goes into the switch itself and discussion of bypassing, but I have not found it yet. The switch needs a good ground, so using pipe dope or the like is discouraged, did find the specs on the switch

 

[skyman2112]

Agree don't change your stainless pump housing, the dealer is either not to bright or just wanting to make some more money.

The pressure switches seam to have a lot of trouble with them over time. There is a thread here which goes into the switch itself and discussion of bypassing, but I have not found it yet. The switch needs a good ground, so using pipe dope or the like is discouraged, did find the specs on the switch

I found the article about a guy that wanted to bypass the pressure switch but it never gave any details other than the resistance of the switch when its not running. Not much help there. Surely someone knows how to do this or has stuck a resister in the signal wire running to the computer. Hopefully someone can find it!!

 

[alldodge]

Memory isn't the best but I'm thinking the computer is looking for different pressures at different rpm's. If this is the case finding a fix will be much harder. Only other route may be to re-flash the ECM and change the parameters the computer is looking for.

In the mean time I'll keep looking

 

[skyman2112]

yeah I don't want to make a dummy sender, just add to the existing signal coming from the original switch. I pretty sure just adding a resistor to the signal wire would do it cause the original signal from the switch will still be there, but just altered by the addition of a resistor of the correct value. Seems like a good theory right LOL.

 

[muc]

Sea water pressure will not cause guardian to bring engine to idle. Sounds like you have more than one problem.

 

[skyman2112]

Sea water pressure will not cause guardian to bring engine to idle. Sounds like you have more than one problem.

well the dealer said the only code in the computer was for water pressure. What does cause gaurdian to bring the engine to idle then? Sounds like you are the one i need to be asking. Thanks!

 

[alldodge]

Here is the listing of guardian faults and power reduction from manual 36

 

[45Auto]

Sounds like your boat could be slowly developing "Bravoitis". Mine did the same thing (2003 8.1L with B3) as yours. Mostly used in fresh water, maybe 5% in brackish. Started as intermittent last year, this year it gradually got worse. I also replaced my stock brass pump (slightly scored) with the Hardin stainless pump in an attempt to fix it. My Smartcraft gauge showed a "Low Water PSI" warning when it happened. It's a common problem, a couple of companies make kits to fix it:

http://www.hardin-marine.com/p-74054...epair-kit.aspx

http://www.amarket.com/BRAVOitis.htm

http://www.amarket.com/IM654.htm

I put the Hardin kit in mine, everything is happy now.

Water hose tunnel is the hole at about 1 o'clock just above the gimbal bearing. The rest of the outdrive looks brand new:

Close up of corrroded hose tunnel: