'94 Q45 EGR whistle, time to replace?

[Q45Nube]

Hey everyone, I'm new to this so very sorry if I sound ignorant. Now with that out of the way here is my issue. I have a 1994 Q45T with 168K, that once the engine is up to normal operating temp a very loud whistle sound is coming from under the hood at idle. Once you depress the excellerator the whistle "almost" goes away and returns once the engine is back to idle. While idling and I'm under the hood I can press on the EGR valve thus changing the tone of the whistle. Any thoughts if the valve is going out or maybe just a gasket? Any help is appreciated.

FYI: I probably won't be able to check this post until tomorrow. Thanks again!

[Q451990]

to NICO!

I would suspect the hose that goes between the EGR and BPT valve (the other flying saucer looking thing near the EGR). I would also make sure that you're not just changing the engine speed with the EGR, and the whistle is coming from somewhere else...

Heath

[Q45Nube]

OK, thank you Heath! I'll check the hoses and see what I come up with. If I have more questions I'll be sure to comment again.

[maxnix]

Better to take out your aggression by cleaning it than to replace it. But the noise is probably what Heath suggested.

[Q45Nube]

Checked lines, can't find any leaks. Still hear loud whistle near EGR valve once engine gets to normal operating temperature.

[maxnix]

Then you haven't found the source yet! Keep looking!

[black g50]

When you find it,post the reason.Mine also is singing.

[black g50]

any updates?

[Q45Nube]

So did some more looking and notice this hose in the picture has caved in some as if someone was pinching it. Seems to be the source of my issue. Does anyone know what this hose is called and what its purpose is? Thanks again everyone.

[redvette33]

In the same picture but under the throttle cable is another vapor line. After doing knock sensors can't find where this hose goes. Anyone? I looked through FSM but nothing

[black g50]

What is that hose for?The big one in pick.Been chasing a whistle sound in that area for while.

[SanCarlosQ45]

Look at EF & EC-232, it is the PCV system hose into the intake. There is a metal tube attatched to the underside of the plenum that runs from the front, where the PCV valve is, to the back right. Mine was pitched and there was a crack as well. Even new this hose is pinched because of the weird angles.

The big one that I think your talking about is the hose to the brake booster. There should be a one way valve in the middle which could be cracked.

[BCC93QT]

If not the hose check the large nut below in the bottom part of the picture. I was hearing a whistle for 2 days and then it sounded like the engine was misfiring when that simple nut came lose. Give it a tighten as well?