Hey all,

This morning I turned my car on and I heard a whinning/buzzing sound coming from under the car. It sounds similar to the sound that the fuel pump makes whenI turn the car on, except that the original fuel pump sounds stops and then this sound starts and stays on. The sound increases in volume as I accelerate, and decreases as I declerate. For the first timeever, last time I filled the tank I decided to use regular grade gas (read an article that said on "modern" engines you could use regular grade if the car doesn't say premium only) after always using the middle grade in the past. Also, I did run the tank pretty low, but I usually do that anyway (I know I shouldn't). So, I've done my research on here and it sounds to me like it's the fuel pump. My questions are, do you guys think it's the fuel pump making the noise? If it is, is this a precursor to fuel pump failure? Is there anything I can do to prevent this failure?

Thanks all!!

 

Sorry, it's just not possible to answer the question without more information. Too many many things can make a noise.

 

Hmm, is there anything specific I can answer? My Blazer is a 97 with about 130k miles. I don't know if the fuel pump has ever been changed. I thought maybe the fact that the pitch of the whine changes as I accelerate/declerate that it might give more clues as to what's the problem. I don't know if it's a coincidence that it started when my tank was really low on gas, and the gas was a lower grade then usual.

 

ok, so I was wrong. I went to a mechanic and he opened the hood and the sound is DEFINATELY coming from the engine bay. It sounds like the belt is making the noise. However, the quasi-mechanic who looked at the car said one of the tensioners looked loose. Would a loose tensioner cause a whinny noise that increases with pitch as I accelerate, and then decreases as I decelerate?

 

Sure could. So would a slipping belt even if the tensioner is good.

 

How can you tell if the belt is slipping?

 

OK, so an update. I was reading a post by BFCOM which helped me a LOT. He even posted a video of his problem and I could hear that he had the same sound that I did. It turned out that he had a bad alternator. So, I went to my car and lo-and-behold, my voltometer was indicating low voltage! I hadn't noticed this before and never thought to look! I noticed on the drive to the mechanic that the dash lighting was dim, and a few times when I pressed down on the windows putton that my radio would turn off. So, I had them replace my alternator and the noise is gone!!!!so, thanks to the board for pointing me in the right direction, and especially BFCOM for posting his video!! .....................however.....

while he was under the hood he used a stethescope and said my "a/c compressor clutch bearings" are "going". he turned my defroster on and there was a quick ticking sound that I had never heard before. The ticking sound isn't there when it's on any other heater setting. On the way home I turned my defroster on and couldn't hear anything either. When I lifted the hood I heard it twice. The ticking (loud) happen for about 3-4 seconds, then turns off, and it happened twice in about 3 minutes. How in the world did THIS problem arise? Could changin an alternator effect the AC compressor??