Loud noise.......But from where

[ghost03]

My brother has a 00' Mustang and has this real annoying squeeking / squelling sound coming from under the hood. I know that its not the belt. It sounds like its coming from inside the engine or just behind it. I cant put my finger on what it could be aside from a belt squeek..I have never heard anything like this especially from inside or just behind the engine. I was wondering if anyone has ever experienced the same thing. I know this is not the mustang board but many of you out there have mustangs

The squeek usually happens once the car is started and then stops after a few seconds. It also happens when he changed gears or at random times not doing anything specific. I hope that some of you out there can help me lead him in the right direction without having him go to a local shop and having them give him the run around. I want him to know what it is so that he can go straight to the shop and give them a more direct probable cause.

Any and all advice is greatly appreciated. Thanks in advance

[Hotrauder]

Rob, if the noise is repeatable a good shop should be able to track it down and isolate it quickly. Also the Mustang Forums might be a good place to ask but he has probably already done that. Good luck. Dennis

[ghost03]

Rob, if the noise is repeatable a good shop should be able to track it down and isolate it quickly. Also the Mustang Forums might be a good place to ask but he has probably already done that. Good luck. Dennis Neither one of us are on the Musyang board. I just hope someone here can help narrow down the problem just to get an idea. Around here all the shops are pretty shady and will tell you nothing is wrong.

[hwy73]

Take the belt completely off and start the engine. If the noise remains, it is not the belt. Might be the idler / tension pulley, they tend to squeak when they start to go bad.
Does the car have a manual transmission? Might be coming from the clutch area if it does.

[DEFYANT]

Rusty flexnut! Yeah thats it!

Or, +1 for the idler

[STLR FN]

Spun Bearing?????

[alarmguy]

Muffler bearing going out.

[RoyLPita]

It could be the cam syncro assy. If it seizes, say "good bye" to that engine.

[ckadiddle]

Put some sticky felt on the hood bumpers and see if the noise goes away.

[CRZYBIKER]

When the engine begins to make that sound, remove the oil fill cap quickly and see if the noise goes away. If this is the case, there is a problem with crankcase pressures (ie: clogged P.C.V valve) My Mustang had something exactly as you describe, turns out the crankcase was building high NEGATIVE pressure due to an aftermarket chrome oil cap I installed. Just a stab, but worth checking.

[Motorhead350]

Could be the alternator. I've had that problem 3 times on my Marauder.