High Pitch Noise

[Rmattajr]

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.

Grew up on this lake and love it, of course it is no Lake Winnipesaukee!

Edited July 21, 2011 by Rmattajr

[Steve B.]

If I'm not mistaken, the vacuum is highest at idle, therefore it would only be heard around idle.

The air intake is closed (mostly) at idle, so max vacuum from piston sucking. Then as you apply throttle, the air intake opens, reducing the suction at the site where the noise is created.

This is also why super hi performance engines, with cam's that overlap valve opening, have vey low vacuum, and sometimes need fuel to be forced into the engine, rather than rely on vacuum only.

Steve B.

[Rmattajr]

If I'm not mistaken, the vacuum is highest at idle, therefore it would only be heard around idle.

The air intake is closed (mostly) at idle, so max vacuum from piston sucking. Then as you apply throttle, the air intake opens, reducing the suction at the site where the noise is created.

This is also why super hi performance engines, with cam's that overlap valve opening, have vey low vacuum, and sometimes need fuel to be forced into the engine, rather than rely on vacuum only.

Steve B.

Steve,

Hit the nail on the head and i was thinking the same thing. We are getting somewhere now, but if i can only find the leak......

[Rmattajr]

WE HAVE A WINNER.... Found the air leak!!!. Under the silver injector bar is 4 plugs two on each side that go into the block/engine. The plugs have a rubber bottom that fits into the engine and then a plug clip with electrical wires on the top. Not sure what these are or are called. I can take a picture and post later but i sprayed the bottom of the plug with some carb cleaner and the noise was gone just like that. What a relief that i found this noise. Now it is just a matter of how hard of a task is it to replace this part or if i should leave it to a professional.

Thanks again for everyone's help, much appreciated.

-Rob-

[Steve B.]

Great news ! Hopefully Piston Pete will chime in on what they are. I think I remember seeing them for sale as replacement parts, and I think they were affordable items.

Let us know how it goes as far as replacing and stuff. Congrats, it will be nice to have a quiet engine again !

Steve B.

[Rmattajr]

Below are the pictures i took of where the noise was coming from. This plug piece below the injector where the clear rubber fits into the engine is just a little bit loose which is causing the noise. What is this piece called and is it easy to replace? Can i just rub some grease around the piece to eliminate the noise?

The noise maker on the left:

Another photo:

Edited July 25, 2011 by Rmattajr

[Rmattajr]

Talked to the mechanic yesterday and he said mentioned the o-rings are likely bad which is causing the injector to be loose and make a vacuum leak noise. Also was told that this is not an incredibly hard fix either and I should have no problem doing this. Relieve the fuel pressure, remove the top injector bar then pull out the one noisy injector, replace the two o-ring's then reassemble.

Just wanted to throw that out there and finish off this post in the case anyone else ever comes across a situation like this.

Again appreciate everyone's help.

[racer808]

Sorry for the old thread revival, but anyone have more info on this? I have a high pitched sound I am trying to figure out. How hard of a task did this end up being?