high pitched noise when Engine revs are 3000rpm


viper_e2000
12-29-2009, 08:28 PM
SORRY ABOUT THE LONG THREAD, JUST WANTED TO MAKE SURE EVERYONE COULD UNDERSTAND HOW THIS HAPPENED, TO BETTER HELP ME DIAGNOSE THE PROBLEM. THANKS.

It been a while since I've had any problems with my thunderbird. Here's what is happening; I drove the car yesterday for about 4 hours at normal speeds, no hard accelerations. I got to my house the car was fine. Then an hour or so later I turn on the car and I drove to my friends house about 10 miles away on the freeway, again no high accelerations, just normal driving. When I get off the freeway, I get to a light and then I accelerated to 45mph and my rpms reached past 3000, then this is when I heard a whining noise then it went away when the rmps dropped after the gear changed( by the way the transmission didn't get stuck the car runs smooth). when I got to his house, I opened up the hood and had him accelerate slowly until he got to 3500 rmp and the noise came back, but as soon as he lets go of the gas, the sound was like a dying out gurgle. I did this several times and figured it was coming from around the bottom of the distributor. What's strange is that the noise doesn't happen when I drive it smoothly,it's only until I do a hard acceleration and the rmps rev up to 3000+ that this noise comes out. The good thing is that it doesn't seem to affect the performance of my t-bird. But I know in time it will so I need to figure out what it is so that I can fix it.
I thought it could be either the intake manifold gasket,bad IAC valve,throttle body,pcv valve, but it sounds like something opens up at 3000rpms, so I don't think it is the intake manifold gasket, cause that would sound more like a hissing noise and it would do it all the time. Any help would be appreciated.
I have a video of the noise,

http://vids.myspace.com/index.cfm?fuseaction=vids.individual&videoid=101795122



Specs:
1991 thunderbird LX, V8 5.0 HO, 230,000miles, turns right on, regular oil changes every 3k miles, I changed the transmission filter 3 times, the last thing I replaced on it was the harmonic balancer.

thunderbirdcoupe89
12-30-2009, 02:36 PM
if its near the base of the distributor, it could be the waterpump bearins dying, or maybe a fan belt?

Blue)(Fusion
12-30-2009, 11:31 PM
Sounds like water pump or alternator bearings. Run the COLD engine without the belt for no more than two minutes to see if the sound goes away. If it goes away with belt removed, it's definitely an accessory - just see which one is harder to turn or makes an unusual noise. If it does not go away with the belt removed, it's something internal.

viper_e2000
01-05-2010, 03:48 AM
I looked at it again and it sounds like it might be the distributor itself, or maybe just the rotor, because the distributor shakes, every time the noise comes up. I know it's not the water pump since the car doesn't heat up much and it can't be any of the pulleys since the noise is not coming from the belt area. I'm going to open up the distributor and see if the rotor is ok. if it is I am going to take out the distributor coil and take a look at the sprocket teeth and see if any are broken. Does anyone know if I have to reset the timing if I replace the distributor, even if I keep everything the same, by setting the distributer exactly the way the old one was and changing the spark plug wires one by one to another distributor cap?

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