Strange Whining Noise?

[chiefmorton]

Drove the truck a little bit today ran some errands in town and before getting home I noticed a slight whining noise when stopped. The noise is very faint but I'm **** about listening for that kinda stuff. I thought maybe the alternator or something but after popping the hood, crawling around all over it and under it everything looks and sounds fine. I can only hear it when I'm sitting in the truck. I also kicked the defroster on to see if it made a change but it didn't. The only thing particular about the noise is when you shut the truck off you can hear the whining noise for a split second after the engine shuts off almost like an air pressure or something backing off. I know it's weird and kind of hard to explain lol. You guys have any ideas?

 

[sewlow]

Fuel pumps in these trucks tend to be noisy. I hear mine for a few seconds after I turn it off. Kinda of a whirrrrring noise as it winds down. It can be heard if I specifically listen for it when the truck's running. After a pump change I've noticed some are noisier than others.
Just a guess though. Kinda hard to diagnose without actually hearing it.

 

[Rewind]

Try this, get in your truck and turn the key to the on position, but don't start the truck and listen to see if you hear the noise. If you do its most likely the fuel pump you're hearing.

Sent from My padded cell using tapatalk 2

 

[chiefmorton]

I'm kinda thinking maybe it's the fuel pump thats why I'm hearing it for a split second after the engine shuts off. I will try setting in it with just the key on and see if I hear it. I did call a local parts place tonight to price a new fuel pump in the event that's what it is, $249.00. I figure it might be easier and quicker to just remove the bed then to drop the tank.

 

[ChrisAU]

Don't expect to get rid of it by replacing it. They all hum.

 

[chiefmorton]

Don't expect to get rid of it by replacing it. They all hum.

Yeah everyone I've ever been around had the same start up whine but mine didn't start having the constant whine til today. I also noticed that the whine doesn't get any louder when you increase rpms so thats making me lean even more towards the fuel pump, time will tell I guess.

 

[heavychevy98]

My old 88 whined. see if turning the radio off stops it.

 

[chiefmorton]

My old 88 whined. see if turning the radio off stops it.

I thought/hoped that might be the problem to but it was already turned off.

 

[chiefmorton]

Just came in from the garage, jumped in the truck and turned the key on, fuel pump did it's initial whine and stopped no noise at all. I decided to fire it up and wouldn't you know no whining noise at all. The only difference between when I heard it earlier today and now is the engine temp, very weird probably gonna be one of those intermitent things that drives a guy crazy lol. I guess I'll see if it happens again.

 

[1993GMCSierra]

Don't go to the parts store for a fuel pump...goodness.

RockAuto.com has an AC Delco pump for $36.79+shipping, and an entire Delphi (also highly recommended) sending unit w/ pump for $198 + shipping.

Both will far outlast the parts store brand units by a long time.