'77 2F Whistle? (1 Viewer)

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Feb 21, 2011
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Location
Madison, WI
Hello,

New to this forum. I picked up a 1977 FJ40 (2F) a week ago. On it's 150 mile voyage home it developed a whistle, for a lack of a better description :

YouTube - '77 FJ40 Whistle?

When the engine is under load, accelerator depressed, the whistle goes away. When the engine is first started it's not there, but once things are warmed up it's there and it seems to come and go. It's not the shrill whine of a belt, but more mechanical.


Any input on what this maybe would be valued. Thanks in advance.

Michael
 
nice cruiser, I like the color

Could be an alternator bearing or something like that. Take your alternator and water pump belts off and rotate everything that has a pulley on it; water pump, alternator, smog pump, power steering pump etc... Feel for roughness in the bearings and listen for squeeks.

Good luck
 
Howdy! Could be a vacuum leak. Intake manifold vacuum is highest when throttle is closed. Maybe a cracked vacuum hose that gets softer with the engine heat as it warms up? John
 
vacuum leak! Mine was an intake manifold gasket that cracked.
 
I used a carb cleaner to spray around the manifold, a little at a time. I noticed a change in the way the motor sounded or a change in the idle. If you use this method. Do it on a cold engine, have a fire extinguisher handy. The carb cleaner is flammable and could flash on you.

You can also use propane from a small propane torch. I set it up with a hose covering the tip of the torch. I turned on the propane torch, very little, and probed around the engine with the hose until I heard a change in the sound or idle of the engine. The propane test is safer.

Good luck! I would like to see what you found.
 
sounds like a vacuum leak to me ( i had one recently on the base of my carb where one carb stud was stripped on the manifold.

Could be intake leak on the manifold too.

I know most exhaust shops will look at the rig / consultation for free if you do not feel like using propane or carb fluid. Just an option.

But yeah sounds like it is pulling air in through a small whole and it will squeal, vacuum lowers under load / rev, so it would logically go away.
 
i have seen the ball check in the pcv valve do this. Its made like a regular whistle.
 
Is it desmogged?? I desmogged mine and had a whistle that you describe at the port off the exhaust manifold that I had used a piece of metal to properly plug. The gasket material I used burned up and would leak shortly thereafter. I found a better gasket material and no more whistle.....what an annoying sound!
 
finally! im not crazy... someone who has the same thing... it's not there when i start the truck but only happens once the rig has warmed up some. i always compare the sound to a tea kettle. it's annoying when you pull up to a stop light or let your foot off the gas at low speed.

my fj mechanic said to check the bolts that bolt the intake to the cylinder head... again leading to a leak.

to me it sounds like the sound is strongest around the carb area and even more so once i take the carb filter off but can not pin point it at all..
 
Have you guys tried the carb cleaner or propane test? I'm betting on a manifold or carb gasket leak at the the manifold...:beer:
 
Hi-also new to the forum / FJ 40 world, heres my input for what its worth.
started having the same problem about a month after I got my truck, a loud whistle after the engine had warmed up, found a leaking gasket between the intake manifold and carb adapter plate.

I bought a roll of Fel-pro gasket material at NAPA for $6.50 and made my own replacement, with plenty of left over material for future use if needed.:banana:

1975 FJ 40 - to be introduced
2F Weber Carb.
 
The reason the whistle goes away under WOT is that manifold vacuum drops to near zero, so no air pulling through the whistle/leak.
 

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