2005 mercruiser 5.0l water pressure sensor

[oilcan2828]

I have a 2005 29' sea ray amberjack equiped with 2/ 260hp 5.0l mercruisers model#6211001n1. I purchased this boat used from a bank forclosure and do not have any of the original manuals. I purchased the SELOC manual But it does not give any troubleshooting tips for these problems.

About a week ago my smartcraft system displyed an error message Water Pressure Sensor on my port side engine. I scrubbed both lower units to clear up any possible blockaged their. I have ran the boat 3 times since and each time i get the same message. The boat seems to run at the normal operating temperture. Any Suggestions.

Second issue is with the same engine. When I returned home from fishing yesterday my engine stalled at the dock.
I attempted to start it and it would not start. I moved the throttle up a little and the engine started. when i returned the throttle to the neutral position it stalls again. I took the boat out for a test run for about a hour running at different RPMs and the port engine ran at 300 to 500 rms less than the starboard. what could of caused this and how can i troubleshoot it.

Thanks in advance for any help you may provide.

 

[Don S]

Re: 2005 mercruiser 5.0l water pressure sensor

What's the Serial number of one of the engines? Those model numbers can't be used for looking anything up.

 

[oilcan2828]

Re: 2005 mercruiser 5.0l water pressure sensor

wa319054

 

[Don S]

Re: 2005 mercruiser 5.0l water pressure sensor

wa319054

Not sure where you are getting those numbers, but they are not Merc SN or model numbers.

 

[newport dave]

Re: 2005 mercruiser 5.0l water pressure sensor

What does your Smartcraft display show for Seapump pressure while the engine is off, but the key is on? What about when the engine is at idle?

 

[oilcan2828]

Re: 2005 mercruiser 5.0l water pressure sensor

It goes immediately into alarm mode after the smartcraft boots up. I got the serial number from the cover on top of the air filter

 

[newport dave]

Re: 2005 mercruiser 5.0l water pressure sensor

It goes immediately into alarm mode after the smartcraft boots up. I got the serial number from the cover on top of the air filter

Well I was hoping you would give the actual pressure readings to help determine if it's a low pressure condition or just a sensor failure (very common on these engines).

As far as the idle problem, it could be a clogged IAC (Idle Air Control) valve muffler (another common problem), or a bad IAC valve, or something else, it's impossible to say without being there. I would start with replacing the muffler, which is a small block of foam that is located in the throat of the throttle body.

 

[oilcan2828]

Re: 2005 mercruiser 5.0l water pressure sensor

how can I troubleshoot the problem here is another serial number ow196415
thanks again

 

[Don S]

Re: 2005 mercruiser 5.0l water pressure sensor

how can I troubleshoot the problem here is another serial number ow196415
thanks again

You now have a real Mercruiser SN for your outdrive, not your engine. Recheck your engine serial number tag. Because there is no such thing as a wa319054 serial number.

 

[oilcan2828]

Re: 2005 mercruiser 5.0l water pressure sensor

Thanks for your patience i think I finally got it right. Serial #0w319056. I ran the boat yesterday again and even before I start the engines I get the water pressure sensor failure, and the same engine is still stalling in the neutral position. Thanks again

 

[Don S]

Re: 2005 mercruiser 5.0l water pressure sensor

You can go Here and download the OEM service manuals for your engine and 555 ECM.
I know you are going to have to hook up a diagnostic tool the the ECM and find out what is going on, then test sensors and wiring, one problem could be causing all of your symptoms.
It's possible you have a raw water pump going bad and causing the pressure alarm, which could actually be causing the engine to go into gaurdian mode, but that should have been lower rpms than what you reported and some other alarms also.
Without the proper electronic equipment, tools and knowhow, you may not be able to troubleshoot it yourself.

 

[newport dave]

Re: 2005 mercruiser 5.0l water pressure sensor

It's possible you have a raw water pump going bad and causing the pressure alarm, which could actually be causing the engine to go into gaurdian mode.

A low pressure fault won't become active until after the engine is running. He said he's getting an fault/alarm before he starts the engine. I believe the most likely cause is that the Seapump Pressure Sensor is bad (very common) or there is a open circuit in one of the sensor circuits.

Check the connection at the sensor (located on the seapump on earlier models and on the power steering cooler on later models), if it looks clean and tight, replace the sensor. Mercruiser part number is 661879010.

As for the no idle issue, pull out the IAC muffler and see it it helps (you won't see this in the service manual, but believe me it's worth tyring). If it doesn't help, you could try replacing the IAC valve, it's another real common failure.

FYI: I listed a couple of common causes for the problems you are having, but Don S. is absolutely correct, proper diagnostics require a service manual and proper equipment. The suggestions I made may take care of the problems, or they may be a waste of money.

 

[oilcan2828]

Re: 2005 mercruiser 5.0l water pressure sensor

Thanks Dave and Don I finaly got to work on the boat today getting ready for the spring. Its been the first nice day in New York in a while. I was able too fix the water pressure sensor it was located on the power steering cooler as you said. It was a very easy fix and the sensor has a new part Number its 881879010 it cost me $80 for anyone else that has the same problem. I will be changing the IAC Valves on the next nice day I hope that clears up my stalling problem.
I have another issue I get a pitot sensor warning on my smartcraft on my port engine. I was able to locate the sensor for the starboard engine but cant seem to find one for the ports side engine. Is it possible both engines use the same sensor. I tried for hours today going through all the wires but still cant seem to find the sensor.
Thanks again for all your help its been great learning about my engines through this process and probably saved me a ton of cash.