5.0 MPI Intermittent Continuous beep, no Smartcraft output

[davidh82]

Hey everyone! I had a small issue last weekend and was hoping to get some advice or thoughts.

I have a 2010 Sundancer with a 5.0 MPI engine. This boat has the Smartcraft gauges and the last few times the alarm went off (once because of a bad water pressure sender and once because of a stuck thermostat) the Smartcraft gauge would specify the source of the problem.

However, last weekend the engine alarm went off a couple times without any output to the gauges. Each time the alarm went off ( it happened two or three times, I don't remember exactly ) I had been on plane and came off plane to pass another boat's wake. Once I reengage the throttle to speed back up, the continuous beep would start. Once the beep would start I'd immediately drop back into neutral out of caution (the engine did not enter the guardian mode) and the beep would stop almost immediately. After letting it idle for a few seconds I'd be able to get back on plane with no further issues.

My first guess is that the drive lube sensor is going bad, and that the sloshing back and forth sets off a false alarm.

Another hint might be that I had just changed the oil prior to taking it out that weekend. I checked all fluids and they all look good. If anything, the engine oil may be a bit too full as the oil comes to the top of the check marks on the dipstick.

Anyway, thank you for reading my post and Id appreciate any thoughts you guys may have on this issue.

 

[CliffA]

could it be the bilge pump alarm you are hearing?....sloshing water in a bilge with a faulty float switch might could cause this.....

cliff

 

[wish2fish]

One way to verify the drive lube is disconnect the wires and the sound will go off.

 

[davidh82]

could it be the bilge pump alarm you are hearing?....sloshing water in a bilge with a faulty float switch might could cause this.....

cliff

Thanks for the fast reply!

Interesting idea, I hadn't thought about water in the bilge. Typically, my bilge stays pretty dry and I don't think there would be enough water in there to set up an alarm.

Is the sensor part of the bilge pump? I wonder if a bad sensor could set of the alarm even if there is no water in the bilge.

 

[davidh82]

One way to verify the drive lube is disconnect the wires and the sound will go off.

I like that idea. I take it that the alarm goes off when the circuit closes?

I'll definitely try this, although since the issue is intermittent I'll need to spend the whole day with it disconnected. However, if it happens at all I'll know for sure this isn't the culprit.


Thank you for the idea!

 

[CliffA]

Thanks for the fast reply!

Interesting idea, I hadn't thought about water in the bilge. Typically, my bilge stays pretty dry and I don't think there would be enough water in there to set up an alarm.

Is the sensor part of the bilge pump? I wonder if a bad sensor could set of the alarm even if there is no water in the bilge.

usually the sensor is part of the float switch in the bilge.....the alarm should sound anytime the water gets high enough to raise the float switch and trigger the pump to energize......

cliff

 

[jason78]

Another hint might be that I had just changed the oil prior to taking it out that weekend. I checked all fluids and they all look good. If anything, the engine oil may be a bit too full as the oil comes to the top of the check marks on the dipstick.

Anyway, thank you for reading my post and Id appreciate any thoughts you guys may have on this issue.

How much oil did you put in?

 

[davidh82]

How much oil did you put in?

I put between four and five quarts, which is about normal, but I was using a manual hand pump and it was giving me issues, so I'm not sure how much oil I was able to empty.

I'm thinking about taking out half a quart before taking the boat out again, however I don't think the oil is high enough on the dipstick to really consider it "overfilled".

 

[davidh82]

In case anybody is interested, looks like the problem wasn't related to the oil or even the drive lube.

When we took the boat out for Memorial Day weekend, I found that the problem had progressed. After driving for a few minutes, the alarm would sound whenever on plane. Additionally, the engine was going into guardian mode and the display was saying that the speed was being reduced.

As soon as I went back to slow speed, the alarm would clear. I could idle around all day without issue. The hint at what was happening is that the Smartcraft gauge showed an exclamation mark under psi where is would normally show ok.

What I found was that the water pressure was only reading about 5 psi while on plane. It looks like this needs to be above 7 psi or the engine will go into guardian mode.

I was fine while idling because I was within the 1-5 psi required. It's also important to note that at no point did the engine run hot. Also, the impeller was replace only a couple months ago.

 

[rpasquarello]

In case anybody is interested, looks like the problem wasn't related to the oil or even the drive lube.

When we took the boat out for Memorial Day weekend, I found that the problem had progressed. After driving for a few minutes, the alarm would sound whenever on plane. Additionally, the engine was going into guardian mode and the display was saying that the speed was being reduced.

As soon as I went back to slow speed, the alarm would clear. I could idle around all day without issue. The hint at what was happening is that the Smartcraft gauge showed an exclamation mark under psi where is would normally show ok.

What I found was that the water pressure was only reading about 5 psi while on plane. It looks like this needs to be above 7 psi or the engine will go into guardian mode.

I was fine while idling because I was within the 1-5 psi required. It's also important to note that at no point did the engine run hot. Also, the impeller was replace only a couple months ago.

Make sure the water intakes on the outdrive are clear of barnacles - inside and out- I had that same issue in 2011.

-Rocco-

 

[bark615]

Once I started reading this I experienced something similar.

This past weekend I was getting a long beep once I came on plane and then would see "Trim Fault" on the smart craft gauge. There was no loss of RPM or speed so the trim level did not change.

I also received the constant beeping and "Check Engine" message which turned out to be low gear lube.

Let us know if you found a solution yet.

 

[davidh82]

Make sure the water intakes on the outdrive are clear of barnacles

That is one thing I had thought of, however the boat is kept on the trailer and there are definitely no barnacles on the outdrive or anywhere else on the boat. I guess there is the potential for some sort of blockage, however I don't appear to have any problem at all with overheating. Additionally, there are moments when the alarm doesn't go off. If there was any type of blockage, I would expect the issue to be fairly constant on the blockage was removed.

 

[davidh82]

Once I started reading this I experienced something similar.
This past weekend I was getting a long beep once I came on plane and then would see "Trim Fault" on the smart craft gauge. There was no loss of RPM or speed so the trim level did not change.
I also received the constant beeping and "Check Engine" message which turned out to be low gear lube.
Let us know if you found a solution yet.

I ordered an aftermarket water pressure sensor (since the OEM one only lasted about a year). Once I replace the sensor I will report back to let you know if this resolved the issue.

Did you message go away once you filled the gear lube? Also, maybe trim fault is suggesting that the trim sensor is bad. Does the trim gauge appear to be reading properly?

 

[bark615]

I ordered an aftermarket water pressure sensor (since the OEM one only lasted about a year). Once I replace the sensor I will report back to let you know if this resolved the issue.

Did you message go away once you filled the gear lube? Also, maybe trim fault is suggesting that the trim sensor is bad. Does the trim gauge appear to be reading properly?

Yes the beep and message went away after filling gear lube.

No - the trim tab is always showing "UP" until the beep starts and then the gauge goes all the way down. Will check the sensor next time at the boat.

 

[davidh82]

You're referring to the trim of your outdrive, right?

I know that my sensor needs to be replaced. It doesn't register that it's being raised until it's about half way up.

There was a thread on this site a while back that had a part number and instructions for rebuilding the trim sensor. Apparently the part is serviceable.

 

[bark615]

You're referring to the trim of your outdrive, right?

I know that my sensor needs to be replaced. It doesn't register that it's being raised until it's about half way up.

There was a thread on this site a while back that had a part number and instructions for rebuilding the trim sensor. Apparently the part is serviceable.

Yes, the outdrive trim.

 

[davidh82]

UPDATE:

Hello everyone, so I have an update to this issue and was hoping to find advice on. I was able to confirm that the alarm was due to the water pressure being low while at high RPM (on plane, about 3 - 4k). So I replaced the water pressure sensor assuming that it was just a bad sensor.

Well, it turns out that the sensor was actually good, because I am seeing the exact same behavior with the new sensor.

Knowing what the issue is, I spent a good amount of time trying to understand the behavior. When the engine is idling and at low RPMs (up to around 1k to 2k RPM) the PSI behaves normally. At idle I get around 3 - 5 psi, then at around 1,500 it just to around 10 psi, at these speeds the PSI is steady. Increasing the throttle causes the PSI to grow at this low range.

The problem starts when I start to accelerate further, the psi starts to lower and even jumps around a bit. At around 3,500 the psi goes anywhere between 3 - 6 psi. Additionally, increasing the RPMs while in this range does not appear to affect the water PSI one way or the other. In other words, I don't see the PSI increase at all if I give it a little more throttle. Ultimately, the PSI dropping while the RPM is high is what triggers the engine alarm.

A couple things that are important to note. The engine never overheats and I just replaced the impeller a few months ago. This problem started a few trips after replacing the impeller.

So here are the things that I think could be the problem:

1. Maybe I left the drive belt a bit loose and it is allowing the raw water pump to slip at higher RPMs. This would of course be the easiest problem to solve and what I am hoping for. What doesn't add up is that I don't see any other issues. The drive belt doesn't squeal, and I don't have any alternator or power steering problems.
2. Maybe I incorrectly installed the new water impeller. If this is the case, then why does the PSI look good at lower RPMs? Also, the engine temp stays steady.
3. There is a problem with the impeller housing that causes pressure to drop when the RPMs are higher. I'm not sure if this makes sense, and I had no problem at all before changing the impeller.
4. There is a clog somewhere in the raw water system. I don't think this makes sense as the clog wouldn't cause the drop in PSI at higher RPMs, right?

It looks like the first step is to check the drive belt tension. I would greatly appreciate any other insight on this issue, or where I should focus my time. I'm hoping that I won't have to pull the raw water pump again, but it looks like I might need to.

Thanks everyone!

 

[scoflaw]

I have read that a grounding issue can cause this. It was recommended to add a grounding wire to the sensor.

 

[davidh82]

I have read that a grounding issue can cause this. It was recommended to add a grounding wire to the sensor.

Thanks scoflaw, that is definitely something to consider, although I really don't want to start splicing in wires unless I am absolutely sure.

One thing that seems to rule out a bad ground is that the PSI reads great while idling and at slow speeds. If it was a bad ground, I would expect it to be more erratic.

 

[Lazy Daze]

With what you're saying, the loose belt sounds like the most likely culprit at this time - possibly you didn't tighten the idler pulley enough and it slowly slipped, loosening the belt. I doubt you put the impeller in wrong since you would have had the issue right away - plus, it will usually flip itself. However, you could still have an issue with the impeller as maybe you sucked up some sand it boogered the impeller.

Tip for replacing the impeller: Take the entire assembly (pump and bracket) as a unit. It's MUCH easier that way and cuts this job down to an hour, if you take your time.

Was the old impeller "whole" when you took it out?

Do you flush the engine after use? Have you had the boat since new, or do you know if it's always been trailered/flushed?