A Weird Whistle that I Can't Pinpoint (1 Viewer)

[Birdmon]

So a weird whistle just started. It is very inconsistent and seems to be most prevalent when I am driving at a consistent speed. The pitch and volume are consistent but it disappears sometimes.

Most noticeable when I am driving on the flats around 25-45MPH.

Does anyone have any ideas what this might be?

 

[spotcruiser]

Describe it.

 

[Birdmon]

 

[Birdmon]

 

[Colorado Boy-74-FJ40]

Vacuum leak? crack in a vacuum hose?

 

[Birdmon]

Vacuum leak? crack in a vacuum hose?

That is what I thought. But it doesn't seem to be. Unless it is just in an odd location. The problem is it is so damn inconsistent that when you want it to whistle it doesn't.

 

[Fast Eddy]

Try pulling off the vacuum line to the brake booster and running without it. Be careful since the brakes will be hard.

 

[Solace in Solitude]

When 44 first arrived, it had an intermittent whistle that I thought was the water pump. Since the water pump was leaking, I replaced it right off.

The whistle hung around... I finally realized it was the VCV (3 o'clock in the yellow circle... Ignore the orange arrow)... The PO had connected two ports to vacuum.... When I pulled the hose off of the leftmost port, the whistle quit... I don't recall, offhand, where that line connects, I have since desmogged and the connections are slightly different.

You didn't say what year you have ... Mine is a '78... As is one of Eddy's, I'm sure he can tell you where it should connect... If that is even your problem...


California):

 

[DSRTRDR]

over time, I get whistling wind noise at the top corner of the doors at certain speeds - goes away when I adjust the windshield to door angle

 

[Bambi Girl]

Hi All
Whistling
More info required . We're is it coming from?
All of these can create strange noise
Uni joints , diff bearings, wheel bearings, transfer box, gear box , water pump. Alternator, thermo fan just to name a few.
Throw a vacuum leak in there just for good luck.
Grab a passenger and take him or her for a ride and play detective.
Post the results.
Cheers



...via IH8MUD app

 

[baas]

These should fix it...

 

[Birdmon]

When 44 first arrived, it had an intermittent whistle that I thought was the water pump. Since the water pump was leaking, I replaced it right off.

The whistle hung around... I finally realized it was the VCV (3 o'clock in the yellow circle... Ignore the orange arrow)... The PO had connected two ports to vacuum.... When I pulled the hose off of the leftmost port, the whistle quit... I don't recall, offhand, where that line connects, I have since desmogged and the connections are slightly different.

You didn't say what year you have ... Mine is a '78... As is one of Eddy's, I'm sure he can tell you where it should connect... If that is even your problem...


California):

Thanks will check this out. Mine is an '83

 

[Birdmon]

These should fix it...

I have actually been turning up the radio!!!

 

[Birdmon]

Hi All
Whistling
More info required . We're is it coming from?
All of these can create strange noise
Uni joints , diff bearings, wheel bearings, transfer box, gear box , water pump. Alternator, thermo fan just to name a few.
Throw a vacuum leak in there just for good luck.
Grab a passenger and take him or her for a ride and play detective.
Post the results.
Cheers



...via IH8MUD app

The whistle is definitely coming from the engine compartment (since I have no top or doors on).

It seems to appear when I am driving at a constant speed. Sometimes it disappears. Other times it happens when I accelerate. But once I lay of the accelerator the whistle stops. It doesn't seem to affect performance but it is annoying and I am sure eventually will cause some issue. I just passed smog about two weeks ago and the whistle was present then.

 

[Bambi Girl]

Hi
So you are thinking this is an engine bay noise.
Ok next question is Does whistle only while you are moving?
OR
Can you get it to whistle while Stationary?
This will narrow down your search.
Cheers



...via IH8MUD app

 

[Fast Eddy]

once I lay of the accelerator the whistle stops.

My money is still on the brake booster. The whistle is at a particular vacuum level and higher or lower vacuum changes it. It's an easy theory to test.

Edit: cleaning out the PCV Valve is another good/easy/cheap idea.

 

[Output Shaft]

I had an intermittent whistle in my 60's engine compartment when I had the head rebuilt and reinstalled. I couldn't find the source of it.

I think I replaced the PCV valve and maybe it went away from that. Not sure though if that was what fixed it, since it was so intermittent.

But it did go away.

 

[Curt]

I had a whistle when the accelerator was pushed, it was between my carb and manifold.

 

[Birdmon]

Hi
So you are thinking this is an engine bay noise.
Ok next question is Does whistle only while you are moving?
OR
Can you get it to whistle while Stationary?
This will narrow down your search.
Cheers



...via IH8MUD app

The whistle is most prevalent while moving. However it does happen while at rest sometimes. It is loudest when moving. When it does happen at rest it is very faint.

Thanks for any help.

 

[Solace in Solitude]

So, engine compartment then... How much vacuum are you reading?

Eddy suggested brake booster, I suggested VCV, Output suggested PCV (possibly), Curt suggested "between carb and manifold" and Colorado-Boy suggested vacuum hose.

Edit:Try Eddy's brake booster suggestion first!

All of these are vacuum-associated... Look for vacuum leaks. I spray with water and listen for an increase in rpms. Others spray with brake cleaner or propane... Be sure you spray between the block and the manifold and around the head.

Failing that, try disconnecting vacuum hoses, one end at at time and see if you can get the whistle to stop... Does re-connecting it make the whistle resume?

Do you know what your compression is running?

Have you checked your coolant in the radiator... Is it frothy?

...and it's not your water pump... Starting to squeal... Like a bearing going?

Good luck!