Loud beeping sound under hood

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Walker434

Walker434

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Hey guys I need some advice. My car (71 dart 318) is making a really load beeping sound under the hood when the car gets warm. When I first start it after sitting all night everything is normal with no noise. As the temperature gets to about 200 and the thermastat opens the beeping sound starts and doesn't stop as long as the car is warm.

I recently replaced the alternator and voltage regulator. The 318 has a small cam, headers, weiand stealth intake and a carter 625 carb. I am at a loss to where this beeping is coming from. It makes the same noise with two different alternators so I have ruled that out. It doesn't seem to be hurting anything (guages are fine), just really annoying. Any help would be appreciated.

Thanks,
 
An old trick.
Take a bar of soap and while the car is running, touch the soap to the sides of each belt for a second or so.
If it's a belt or pulley it will shut up temporarily.
Really easy way to rule them out.
 
TrailBeast said:
An old trick.
Take a bar of soap and while the car is running, touch the soap to the sides of each belt for a second or so.
If it's a belt or pulley it will shut up temporarily.
Really easy way to rule them out.
Click to expand...


LOL, you must be in my generation. I have done that for years.
 
Is it a beep or a shrill squeak.
If a squeak it could be your water pump.
If you have A/C could be tension pulley if there is one.

After your car is warmed up to temp and starts making the noise. Shut it down and remove the belts start it up and see if the noise is gone. Also when you have it shut down check the shaft on the water pump for any play in it.
 
norshorblufish said:
After your car is warmed up to temp and starts making the noise. Shut it down and remove the belts start it up and see if the noise is gone.QUOTE]

The soap is WAY easier and tells you the same thing without having to remove and replace the belts.
Click to expand...
 
A failing radiator cap can make a intermittent sound sort of like a piezo buzzer.
 
That only tells if the belts are slipping. If the water pump or the tension pulley bearing was going removing the belts the noise should stop.
 
norshorblufish said:
That only tells if the belts are slipping. If the water pump or the tension pulley bearing was going removing the belts the noise should stop.
Click to expand...

That would be fine after I soaped the belts and it didn't make any difference.
If you take them off first seams like it could be the longer way to the answer if it's just a squeaky belt.
 
One of many uses for the bar of Ivory in the toolbox! Soap first, then remove belts if necessary.....
 
Tried the bar of soap last night and the noise is still there, it didn't even stop temporarily. My next step will be remove the belts and start it to see if the noise is still there I just didn't have time last night. I am thinking it has something to do with the cooling system since the noise starts the first time the thermastat opens. I'll let you guys know what I figure out after removing the belt. By the way it's a manual steering no AC car so I only have the one belt. Thanks for the help.
 
I wish I could hear this noise.
What do you mean by loud beeping, how fast?
Can you describe it better?
Does the speed of the beeping change with engine speed?
 
Something like this?... [ame="http://www.youtube.com/watch?v=Qi6vWpc3Hs0"]Dumb and Dumber - The most annoying sound in the world - YouTube[/ame]
 
After the noise starts it is a loud high pitch beep or screetch at idle. It changes pitch slightly when you give it throttle and will sometimes go away if you goose the gas pretty hard but then you pull up to a stop light and it starts again at idle. The sound is never there when the engine is cold, it only starts when the engine warms up. I still haven't had time to take the belt off but will definetly try that this weekend.

It is a similar sound to the beeping in your ears after you shoot a handgun with no ear protection. Make sense?
 
I think "A beep sound" is throwing us a curve. A squeel is more common. If the water pump is bad it can make the belt squeel. It can also push the impeller through the timing cover so you want to check that. Drop the belt and wiggle the fan/pulley. If it moves around there's your problem. They can sometimes get a lot of play in them without ever leaking a drop of water.
The lip of the front seal can squeel on the balancer too.
 
try a diffrent radiator cap it may be leaking steam on the roadrunner causing it to beep
 
Sounds like it could be a vacuum leak like already mentioned.
Another old school trick, take a peice of hose a couple of feet long and put one end to your ear and "Snoop" for the noise with the other end.
You'd be amazed how well this works for finding a noise.

Chk all around the intake and carb and zero in on where it's loudest.
 
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