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Mercruiser 50L V8 2006 model 260hp

A

alon

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"I am situated in Cape Town, S

"I am situated in Cape Town, South Africa.

I have a 21 foot bow-rider with the above motor.

The motor has 30 hours on it.

When the motor is at full throttle the whistle comes on to indicate overheating.

At idle it beeps a few times and on the cruise it beeps a couple ot times but tis only at full throttle that the sensor activates.

I am not mechanically minded but my mechanic has changed the thermostat as te boat stood for 6 months.

That did not help.

He has also checked all of the pipes and they are all running without blockage.

According to him the manifold remians cold and it is not the implellor.

Can anyone shed light on this problem?"
 
Is the engine sea water cooled

Is the engine sea water cooled or does it have a heat exchanger with coolant (anti freeze typically) ?
 
"Assuming it is a carbed engin

"Assuming it is a carbed engine, the alarm could also indicate low oil pressure, low drive oil level, or low rawwater pump pressure.

A high temperature alarm would be evident by a high temp reading on the panel gauge.

If all the guages look OK, my guess is the drive oil reservoir is low, or the raw water pump is faulty, or the water intakes are partly plugged or something similar.

Rod"
 
"the boat is used is salt wate

"the boat is used is salt water and moored in the water, not on an air-berth.

I would assume it is a fuel injected motor, but would have to confirm this."
 
"Assuming your engine is a 5.0

"Assuming your engine is a 5.0MPI, it will have two alarm modes. A "soft alarm" which is two beeps per minute, for less severe problems and a "hard alarm" which is a constant horn, for more serious conditions. This can be caused by a lot of different things, and the best way to diagnose this problem is to connect a scan tool and see what Active Faults show up and what faults are strored in the freezframe memory. This will tell you exactly what needs to be repaired."
 
"We spent the morning on the b

"We spent the morning on the boat with the diagnostic leads and laptop.

No faults were detected but what we found out was the the rev counter was under reading and it was the rev limiter that was sounding at aprox 4500 RPM.

As for the double beep every min, we are still uncertain what this is but the mechanic will analyze the info and see if he can get to the bottom if it.

As for the over revving, I have been advised to move from a 19 to a 21 inch porp"
 
"I don't know why the mech

"I don't know why the mechanic wouldn't be able to tell exactly what Active Fault is set (causing the alarm).

Anytime a fault is active the Available Power will be reduced to 90%, meaning the rev limit will is reduced to 4500-4600 RPM. Thats why you get an overspeed fault at that RPM.

If you can post the list of active faults and/or the contents of the Freezframe memory, I will tell you exactly what the problem is."
 
Dave

Tx for that offer.

Dave

Tx for that offer.

I will get the diagnostic email from the mechanic and send it to you.

I realy appriciate the assistance.
 
I have spoken to the mechanics

I have spoken to the mechanics assistant this am ( we are 9 hours ahead of you in CA) and he murmured that it might be the "oil reservoir sensor" that it faulty as when he disconnected it the 2 beeps every min went away.

I will send you the diagnostics when I recieve them.


tx

Alon
 
"Alon,
I was not able to open

"Alon,
I was not able to open the files, except for the .tif file. What I was really hoping you would send is the diagnostic report that Diacom generates as a .rtf file. This report tells you the current Active Faults and the lists the Contents of the Freezframe memory.

Dave"
 
Dave

I have emailed you tho

Dave

I have emailed you those stats.

I appreciate your assistance.

Pls let me know.

Alon
 
"Hi Alon,
Got your email. The

"Hi Alon,
Got your email. There is an active fault called "BLK PSI CKT LOW". This is why your getting an alarm and are restricted to 90% Available Power. Usually this means 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."
 
"Dave

Good news and bad new

"Dave

Good news and bad news!!!!

We replaced that part and guess what....... double beep has gone and by the feel of things we have 100% power back!!! There is a significant difference.

Your diagnosis was spot on!!!

Now for the bad news.

At full throttle, after a minute or so of flooring it, we get the long and constant beep.

Mechanic opened motor cover and felt the top manifolds and it was hot, so out came the scan tool......

Problem......... laptop battery flat....... TIA ( This is Africa!!!!)

We have already replaced the thermostat and mechanic says water is flowing well so he is convinced we are in for a new impeller.


Thanks for your help to date and pls let me know!!
Does this sound right?"
 
"Alon,
Good to hear you found

"Alon,
Good to hear you found the problem. I noticed on the data that you sent me the temp seemed to climb rapidly when the engine was throttled up, so I'm not too surprised about the overheat. Impellor is a good place to start.
dave"
 
"Dave

They replaced the im

"Dave

They replaced the impeller today and we will need to wait for the wind to drop before water testing it.

It did not look bad according to the mechanic.

Can the eye see if it is at fault.

He said that seeing the boat had stood for a while it could be tat is is not forming the shape required but the eye can's see that.

Seeing that this problem arose at high revs when under load on the water is there any accurate test it out the water, or does it have to be at full throttle on the water?

Pls let me know

Regards

Alon"
 
Dave

PROBLEM SOLVED!!!!!!!!

Dave

PROBLEM SOLVED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

It was the impeller!!

They managed to water test it this evening and the boats runs like a new one!

Tx for the help!!!!!

I sincerely appreciate it.

Regards

Alon
 
"Alon, Thank you for posting t

"Alon, Thank you for posting the outcome and reason for it. All too often we only hear the question, not the cure. I'm here to learn as well as try to help. People like you, as well as Dave and others, help me accomplish my goal. Good Luck, Al W."
 
"It still amazes me how a part

"It still amazes me how a part can look good yet still be the source of the problem. That tells me we all need to take another look at something that we have cleared as "not the problem" and can not determine the root cause of the symptoms.
Spring; where fore art thou?
snow.gif
"
 
"Alon,
Glad I could help, and

"Alon,
Glad I could help, and thanks for posting your results. Go have some fun, summer is coming soon!(at least for you it is).

Dave"
 
Sorry Dave.

Just one correc

Sorry Dave.

Just one correction...

Summer is not coming................ SUMMER IS HERE!!!!!!!!!!
 
Dave

I have posted another

Dave

I have posted another fault.

YOurs or anybody else's input would be appreciated.

Regards
 
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