Merc 5.0 mpi alarm

[Enigma]

My 5.0 mpi is beeping at roughly 2 min intervals. Nothing obvious, all levels correct and is running fine.
Any ideas?

 

[newport dave]

Re: Merc 5.0 mpi alarm

Two beeps per minute is called a "soft alarm", meaning that there is an active fault code. There are several faults (at least 26) that can cause a soft alarm and you will need to connect a scan tool to determine what the active fault code is. The most common one is an IAC fault.

 

[Enigma]

Re: Merc 5.0 mpi alarm

Thanks for the reply, but what is an IAC fault?

 

[burp]

Re: Merc 5.0 mpi alarm

Newport Dave is correct. Too many possible causes for the 2 beeps per minute alarm to try guessing the cause. A scan tool/dealer is your best bet to find the source of the alarm.

 

[burp]

Re: Merc 5.0 mpi alarm

IAC- Idle Air Control

A common symptom is rough idling or must throttle it up to keep the engine running.

 

[Don S]

Re: Merc 5.0 mpi alarm

What is the SN of your engine? A year might help a little bit, but SN is best.

 

[Enigma]

Re: Merc 5.0 mpi alarm

I have not got the SN to hand, but its an early one 2002.
I may have been mistaken when I said all levels ok.... on closer inspection I had to top up the PAS fluid. I then ran her on the muffs (weathers awful here) and no beep! This may just be coincidence as I don't know if there is a soft alarm for PAS fluid. Will try and get it on a fault code reader when I can...

 

[Don S]

Re: Merc 5.0 mpi alarm

What's PAS fluid? Assuming that's for the Power Steering, then no there are no sensors there that would set off an alarm.

 

[newport dave]

Re: Merc 5.0 mpi alarm

I have not got the SN to hand, but its an early one 2002.
I may have been mistaken when I said all levels ok.... on closer inspection I had to top up the PAS fluid. I then ran her on the muffs (weathers awful here) and no beep! This may just be coincidence as I don't know if there is a soft alarm for PAS fluid. Will try and get it on a fault code reader when I can...

As Don said, there is no alarm for low power steering fluid. Even if you didn't get an alarm on the hose, have it checked out. It could be low sea pump pressure fault and the pressure from the hose was enough to make the fault go inactive.

Anyway, these alarms rarely go away, and will be sure to resurface at the worst possible time. Also, just FYI, when you get a soft alarm the ECM will reduce the Available Power to 90%.

 

[Chesapeakester]

Re: Merc 5.0 mpi alarm

5.0 MPI Bravo Double Beep alarms

I've seen a few older posts about the same problem I am having and was hoping there was some new insight other than taking it to the shop.

I get two loud beeps about a minute apart when underway... finally quit on me and I was Able to start the S. engine and keep it running in neutral (1000 rpms)? So I had power steering for the good engine and get back across the Bay before nightfall. I see a lot about an Idle sensor that folks seems to think is my problem ($80) and wanted to ask you all if you experienced this before. Fluids and temps fine on both engines..... Just can't keep it running at an idle and shift into gear before it quits.

Thanks for any help.

 

[jellyfish]

Re: Merc 5.0 mpi alarm

My 5.0 mpi is beeping at roughly 2 min intervals. Nothing obvious, all levels correct and is running fine.
Any ideas?

MPI engines are know for the IAC going bad and the symptoms manifest themselves in several way including the 2 beeps. The part is +/-$90 and can be changed in 10 minutes. You will need a hex tool and a new gasket..

Several people carry a spare just in case....

 

[Don S]

Re: Merc 5.0 mpi alarm

Start a new thread with your question, not at the end of someone elses question that is over a year old.