Sounds Like a Vacuum Leak, High Pitched Whistle From Engine

[topless98gt]

I've been experiencing a high pitch whistle from my engine for the past two months or so, but never really thought anything of it. It is really starting to get annoying now. It sounds like it may be a vacuum leak or something, but I figured I'd ask around to see if anyone has ever experienced something similar. It is coming from the engine bay, I think near the middle.

Thanks for any advice/info in advance!

 

[joshjwc9]

Does it do it all of the time? Or with AC/Heat on? Mine was making a similar sound and it was the AC idler pulley sparking and not engaging right.

 

[Rusty67]

How many miles on the engine ? Check the PCV valve ?

 

[lvmustanggt]

I do have same problem and don't even know where it's comming from
I change everything pcv, iac, egr, alternator, pulleys, gasket with no luck

 

[scupking]

Mine does the same thing and sounds like a supercharger. Mine is coming from the pullies though.

 

[RedDaemon]

when does it happen?

 

[GettinThere]

I've been experiencing a high pitch whistle from my engine for the past two months or so...It is coming from the engine bay, I think near the middle.

Do you have an aftermarket plenum and/or throttle body?

 

[lvmustanggt]

mine starts at around 2000 rpm.

 

[tank_567]

it could be the tensioner pulley or the tensioner its self. I did you replace with new?

 

[lvmustanggt]

I did change new tensioner

 

[2000fordstanggt]

my gatorback always made noise..not sure what type of belt you have though

 

[topless98gt]

It does it all the time, regardless of A/C position. My A/C compressor is out, though, but it was doing it before that went. It doesn't sound like it's coming from that, but I can check again.

I can only really hear it at idle because my exhaust is so loud.

22x,000 miles on the engine. Stock plenum, stock throttle body. I have never changed the belts.

It was making this sound long before I successfully made the 1500 mile trip to Canada with no problems at all. Yeah, I was surprised too!

I will check all of the pulleys and the PCV valve (located on the passenger side of a 98 GT, right?).

I apologize for not being around much. I've been living it up here in Toronto

 

[GettinThere]

Maybe there's an air leak around the air box / filter, or around the IAC?

 

[topless98gt]

Maybe there's an air leak around the air box / filter, or around the IAC?

Yeah, maybe it's time to clean my K&N. I'll check to see if it alters with that.

 

[Rusty67]

If you want to see if the manifold has some sort of vaccume leek you can spray carb cleaner around the areas where the manifold/plenum seals and if you hear the engine change RPMs you have a leek there.