Dash Whistle - HELP before I go crazy

[russmike]

Hi, just bought a 99 SLE with 46K original miles - garage kept, one owner. Looks great inside and out and runs well, too. Just changed fluids, brake shoes, serpentine belt (and pulley), and I leave tomorrow to drive cross-country.

At 35mph +, I hear a whistling/screeching sound, not engine speed related, doesn't increase in intensity or frequency with speed - doesn't go away at higher speeds; sounds like it's coming from the center of the dash, behind the radio
- fan motor - not the problem - fan motor off, still there (even unplugged the power to the fan motor)
- it might diminish when I coast, as if to a stop
- couldn't find any holes in the firewall
- all vacuum lines under the hood appear to be solid and supple
- no obvious things sticking out in the air flow

any ideas, please? Thanks so much. Russ

 

[bigdog9191999]

could be a vac line in the dash, that age with those miles means it has sat a lot and possible mouse or something got to one of them.

 

[TollKeeper]

Another idea is to take the air intake system off, from the intake where the air filter sits, all the way to the throttle body. During reinstallation of the intake, these were known to get the plastic edges where the clamps are, to fold over, and create an air gap. That air gap could start a whistle, as the air would be coming in there.

 

[YukonGTmaster]

Hi, just bought a 99 SLE with 46K original miles - garage kept, one owner. Looks great inside and out and runs well, too. Just changed fluids, brake shoes, serpentine belt (and pulley), and I leave tomorrow to drive cross-country.

At 35mph +, I hear a whistling/screeching sound, not engine speed related, doesn't increase in intensity or frequency with speed - doesn't go away at higher speeds; sounds like it's coming from the center of the dash, behind the radio
- fan motor - not the problem - fan motor off, still there (even unplugged the power to the fan motor)
- it might diminish when I coast, as if to a stop
- couldn't find any holes in the firewall
- all vacuum lines under the hood appear to be solid and supple
- no obvious things sticking out in the air flow

any ideas, please? Thanks so much. Russ

Can you post video with sound?

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

You are already receiving replies/suggestions from the knowledgeable folks on this Forum.

 

[Rocket Man]

An we see pics of this unicorn you speak of? A ‘99 with 46k miles? Crazy!

 

[Jimmyy]

I had a windshield that whistled. Try pushing on the glass when moving and to see if the pitch changes.

 

[exp500]

Underhood on firewall above heater is small vac line. Unplug and go for drive. That supplies dash vac.

 

[TollKeeper]

I had a windshield that whistled. Try pushing on the glass when moving and to see if the pitch changes.

Actually, try putting painters tape around the edge of the windshield. Take it for a drive. No whistle, you know its somewhere in the windshield seal. You can then pull it off in sections until the whistle returns (assuming its in the windshield).

 

[russmike]

Hi, just bought a 99 SLE with 46K original miles - garage kept, one owner. Looks great inside and out and runs well, too. Just changed fluids, brake shoes, serpentine belt (and pulley), and I leave tomorrow to drive cross-country.

At 35mph +, I hear a whistling/screeching sound, not engine speed related, doesn't increase in intensity or frequency with speed - doesn't go away at higher speeds; sounds like it's coming from the center of the dash, behind the radio
- fan motor - not the problem - fan motor off, still there (even unplugged the power to the fan motor)
- it might diminish when I coast, as if to a stop
- couldn't find any holes in the firewall
- all vacuum lines under the hood appear to be solid and supple
- no obvious things sticking out in the air flow

any ideas, please? Thanks so much. Russ

Friends, so sorry for not replying sooner. I checked most of your suggestions - to no avail; The sound seemed to change a bit over time - and sounded VERY MUCH like a brake pad wear indicator (Which it wasn't - nor was there anything in the dust shield making contact). Anyhow, with my available time exhausted, I jumped in the Yukon and drove it 1800 miles from MD to Boulder CO. I figured if something broke, it broke. Well, nothing broke, except that the noise, while still present, diminished in volume. I have since 'sold' the truck to my youngest son (who can say no to a veteran?). I so appreciate all your thoughtful and considerate advice.