High Pitch Noise

[Rmattajr]

Hi everyone,

Brought my 2002 Sunsetter 23foot xti to the mechanic to have it looked at because of a high pitched noise it is giving off. After looking at it for 20 minutes we pinpointed the area but he couldnt figure out what the noise was coming from. Coming off the side of the engine where the fuel pump is but the noise is not coming from the fuel pump. The mechanic seems to think there is an air leak somewhere in that area. Engine makes this high pitch noise, almost like a high pitch whistle. Goes away when you give it some gas (not the engine overpowering the high pitched noise).

Boat runs excellent besides this annoying high pitched sound. Has anyone had any experience with an issue like this and may have an idea of it is in fact an air leak?

Appreciate it.

[CedarLakeSkier]

Is it like a whistle? If so, check this thread

[Rmattajr]

Thanks,

We did actually also take off the flame arrestor and could still hear the noise. Sounds like it was coming from the injector bar area where the fuel pressure regulator is.

[Devin Perry]

The throttle blade will make a whistling noise when it is at idle and just off idle and it is normal and might be louder with the spark arrestor off.

[Rmattajr]

The throttle blade will make a whistling noise when it is at idle and just off idle and it is normal and might be louder with the spark arrestor off.

Took the spark arrestor off last night and the noise didn't seem to get any louder. If i place my hand over the area there the fuel pressure regulator it seems to block some of the noise. Still feel like it is coming from that general area. this one is very frustrating. The noise is just very irritation like ringing ears or a dog whistle.

[Rmattajr]

So i went down to the boat this afternoon to take a video of what i am hearing, I figured it would be the best way to describe this noise. I took off the flame arrestor and cleaned it up but it really wasn't dirty to begin with. Still i feel like this noise is coming from the side of the engine where the fuel pump is but 95% sure this noise is not coming from the fuel pump. Also does not get any louder with the flame arrestor off. Sounds more on top of the engine and to the side where the fuel injector bar is. This one is really driving me crazy because i have no clue what it is. Again my boat is a 2002 23 foot Sunsetter XTI monsoon engine.

Here are the two videos.

-This one i started the boat and you hear it in neutral, it typically goes away after about 1,500 rpm's

My link

-Here i gave it some gas and you can hear it go away, and then as i pull back the throttle it slightly comes back. Makes me feel like there is some air leak somewhere.

My link

Thoughts??? this is my last ditch effort before i bring it to another mechanic,

Really appreciate it.

Edited July 18, 2011 by Rmattajr

[water_junky]

So i went down to the boat this afternoon to take a video of what i am hearing, I figured it would be the best way to describe this noise. I took off the flame arrestor and cleaned it up but it really wasn't dirty to begin with. Still i feel like this noise is coming from the side of the engine where the fuel pump is but 95% sure this noise is not coming from the fuel pump. Also does not get any louder with the flame arrestor off. Sounds more on top of the engine and to the side where the fuel injector bar is. This one is really driving me crazy because i have no clue what it is. Again my boat is a 2002 23 foot Sunsetter XTI monsoon engine.

Here are the two videos.

-This one i started the boat and you hear it in neutral, it typically goes away after about 1,500 rpm's

My link

-Here i gave it some gas and you can hear it go away, and then as i pull back the throttle it slightly comes back. Makes me feel like there is some air leak somewhere.

My link

Thoughts??? this is my last ditch effort before i bring it to another mechanic,

Really appreciate it.

That is a very strange noise and very very irritating. I have no idea, but good luck.

[Tory1340]

I haven't listened to your vid yet, I'll do that later in peace & quiet when I can pay attention. Last season I had a horrible, brain-busting squeal coming from the engine area. Diagnosis at the dock and under way led me to the fuel pump area. Directly beneath it on my 06 VLX is a filter. When I disconnected and removed said filter and gave it a thorough cleaning, the amount of crud in the solvent was substantial. I flushed it a few more times and reinstalled the filter and it has been quiet ever since. Check the fuel line leading to the tank side of the fuel pump for this filter, and check the screen inside it as well. Good luck.

[Rmattajr]

I haven't listened to your vid yet, I'll do that later in peace & quiet when I can pay attention. Last season I had a horrible, brain-busting squeal coming from the engine area. Diagnosis at the dock and under way led me to the fuel pump area. Directly beneath it on my 06 VLX is a filter. When I disconnected and removed said filter and gave it a thorough cleaning, the amount of crud in the solvent was substantial. I flushed it a few more times and reinstalled the filter and it has been quiet ever since. Check the fuel line leading to the tank side of the fuel pump for this filter, and check the screen inside it as well. Good luck.

Thanks for the ideas and yes this is a very brain busting noise too haha, take a listen, not really a squeal but more a computer sounding high pitch noise.

I replaced the fuel filter on this a few weeks ago after the noise started. Thought that maybe the fuel filter may be clogged, it was an inline filter that sat on top of the fuel tank yet it was dirty but nothing terrible. I believe this is the only filter on the boat(dealer told me this too) and from what i have read that all boats after 2002 they stopped putting in the high pressure fuel filter as a second filter. I checked today and couldn't find any other filter and I think this was what you were telling me to do? I haven't cleaned the bottom screen that you mentioned below the fuel pump but will get to that tomorrow. Cant hurt to have it cleaned out anyways right?

Edited July 19, 2011 by Rmattajr

[Tory1340]

For sure, check that screen if your setup is the same as the VLX. Sounds like what I had - a dial-up modem on steroids.

[Rmattajr]

For sure, check that screen if your setup is the same as the VLX. Sounds like what I had - a dial-up modem on steroids.

Ok cool, I will let you know what happens when i look into it after work tomorrow.

Thanks for the feedback!

[Steve B.]

Very interesting. That motor does sound sweet other than that !

Steve B.

[Rmattajr]

One last question before i pull off that screen. Looks like the rubber hose in connected to a brass fitting. should i take them both off? Where is the fuel pump screen?

Thanks

[Tory1340]

One last question before i pull off that screen. Looks like the rubber hose in connected to a brass fitting. should i take them both off? Where is the fuel pump screen?

Thanks

IIRC, the hose at the bottom is the supply side from the fuel tank. Clamp it off with a vise grip before disconnecting otherwise you'll have a bilge full of gas. The screen in integrated in the filter, so you'll have to remove it entirely, which should be pretty self-explanatory.

Of course I'm sitting at my kitchen table remembering what I did a year ago, so I could be off a bit.

[Pondking]

I get a similar issue once in a while. It goes away by replacing the spin-on fuel filter by the fuel pump. the part costs about $10. My monsoon has 2 fuel filters. The inline above the tank and a spin-on by the pump. Some marinas get stuff in their fuel and it can plug the filter a bit causing that vaccum sound.

Easy fix. It only took me 20 mins and I'm not that mechanically savy.

Best of luck!

[Rmattajr]

No dice last night on the fuel pump screen cleaning. Got it off and was pretty easy to get to but was clean, no issues. Feel like if it was a clogged fuel issue the boat would bogg down and not run well. It actually runs like new but except for that damn noise.

Back to the drawing board i guess....bummer

Edited July 20, 2011 by Rmattajr

[Rmattajr]

I get a similar issue once in a while. It goes away by replacing the spin-on fuel filter by the fuel pump. the part costs about $10. My monsoon has 2 fuel filters. The inline above the tank and a spin-on by the pump. Some marinas get stuff in their fuel and it can plug the filter a bit causing that vaccum sound.

Easy fix. It only took me 20 mins and I'm not that mechanically savy.

Best of luck!

Pond King,

Thanks for your idea. I was told that i only have one fuel filter by the marina parts manager but to be honest he didn't seem completely sure but I read that Malibu got rid of the second fuel filter in 2002 models.

What year is your Sunsetter? Where is this spin on filter located...is it on the same bracket mounted next to the fuel pump? Would this second filter be the high pressure fuel filter?

[Rmattajr]

Pond King,

I pulled these pictures off other posts because the first picture is what my fuel pump area looks like and i don't see where the other fuel filter would be.

Is this the filter you mentioned to remove?

[SmoothWaterMan]

My money is on an intake leak - either intake gasket, hose, pcv valve, or connection.

Bring it up if you need to.

Peter

[Rmattajr]

My money is on an intake leak - either intake gasket, hose, pcv valve, or connection.

Bring it up if you need to.

Peter

Smooth that was my initial guess. Where is the intake gasket, any quick ideas where i should look?

Thanks

[SmoothWaterMan]

Intake gaskets are under the intake manifold. Aside from spraying the edges with some accelerant, which can be dangerous, can't really inspect it.

Peter

[scfdfireman]

I was going to say vacuum leak too (possibly an intake gasket or hose) or accessory bearing (alternator). To help find the vacuum leak spray some WD-40 around the area where the block and intake meets. If there's a leak it will suck the WD-40 in and the idle will change. If it's a bearing get a long screwdriver or pipe ad place the metal end on the accessory and the other to your ear. The sound will e transmitted up so you can here it better.

[Rmattajr]

My money is on an intake leak - either intake gasket, hose, pcv valve, or connection.

Bring it up if you need to.

Peter

Also the mechanic who looked it over quickly said to spray carb cleaner around some of the hoses and gaskets to see if it could pinpoint the leak.

[Pondking]

Pond King,

I pulled these pictures off other posts because the first picture is what my fuel pump area looks like and i don't see where the other fuel filter would be.

Is this the filter you mentioned to remove?

My SSLXI is 99. Yes that is the filter I was referring to. Canister style, held tighly in place with bracket. Changing that filter got rid of very similar noise. By your comments I'm guessing that is not your motor box.

As I said I'm not real mechanically savy but, something is creating a vaccum at idle (In the words of Joe Namath to Howard cosell...I have an amazing grasp of the obvious). By your info I would think fuel line cut, pin hole, even seal to pump. People on this post are way more mechanically qualified to advise you on this. I'm just trying to be helpfull.

Edited July 20, 2011 by Pondking

[Tory1340]

Sorry to hear it's still a problem. As PK said, trying to help based on what worked for me previously. Good luck in your quest for silencing the whistle.

--Tory.

BTW, I skied many years ago on Candlewood with a buddy one weekend.