Fuel Pump whine

CapnDean · April 1, 2005

2001 GMC Sierra 1500 4.8L

Recently my fuel pump has begun to sing to me. I have known this to occur on older trucks. I know of folks whose trucks fuel pumps have always whined, but mine until recently never did.

I have nearly 60,000 miles on my original fuel pump, I have changed the filter once and that was at 45,000 miles or so.

I am not suffering from ANY performance problems, my fuel gage reads accurately as it always has.... My fuel mileage is still excellent (17-18 MPG for my commute).

The singing is not predicatable, sometimes it sings....sometimes it does not. It does not seem to relate to whether the truck has been running a long time or a short time. E.G. It sang this morning when I fired it up to go to work, it was singing when I got there 20 miles later. It did not sing on the way home nor was it singing when I got here. It did not sing when I left to go to the liquor store, it was singing when I left.

Does anyone know if I am about to be forced into replacing my fuel pump?

Is this the sign of things to come? Or should I just wait it out?

CapnDean

BADGERMAN · April 1, 2005

I had a 97 GMC Sierra that started to sing about 75000 miles, needless to say about 80000 miles I was replacing the fuel pump. Replaced it with an Autozone pump and it failed about 5 months later. So I gave up and had a GM pump put in and never had a problem after that.

Ben · April 1, 2005

Fuel filters should be changed every 1,000 gallons of fuel, especially GM's which has a return cycle instead of an accumulator.

Once the pump tries to pump through a partially plugged filter, it will die soon.

Most start to make a racket or change in sound.

It's inside the tank, so the tank has to be dropped. Several hundred bucks just for the parts and about 4 hours labor.

Cheaper to change the $7 buck filter often.

Get to know how a "normal" fuel pump sounds. If it should change in sound, be prepared for about $500 bucks to have it changed...soon...

Wingnut · April 1, 2005

Mine has been whining off and on since I bought it (the '02). I'm close to 70k now....We'll see.

Oh, and don't drop the tank to change it out. Take the bed off. It's faster and a lot easier.

Bish · April 1, 2005

Follow Ben's advice and get ready when the sound changes. Mine was noisy from day 1. At about 70K the pitch changed to a higher note and louder. 2K miles later it failed completely.

Also agree with the filter change every 1000 miles. Cheap insurance as my pump replacement was $600. Got 70K on the replacement and it is still nice and quiet.

CapnDean · April 1, 2005

I replaced on on a 1997 Z71 for a friend of mine. His gage was out too.

The advice that served me well on this one was this:

"If the tank is empty or light on fuel, drop the tank. If the tank is full, remove the bed."

In this case the tank had minimal fuel in it so we dropped it.

It was a pain in the butt to do for certain.... But as all things go it was relatively straight forward.

Dean

tmf6902 · April 1, 2005

Mine has whined since day 1....I change my filter about every 25K....but it's external so it's easy.

Frank S · April 1, 2005

It varies really, though the sound is a good indication that a problem may be on the horizon. The pump on my '01 1500 4.8 worktruck makes different pitched noises and seems to change just whenever it feels like it. The truck has 105,xxx miles on it with no problems and the pump has been doing this since around the 40-50k mile mark.

If you're concerned with it, get yourself a pressure tester and check the pressure once a month or every other week. You should be at 62 psi if it's still perofrming optimal. You can get away with it being a little lower but if you have someone ease down on the throttle a bit and the pressure comes up and then falls, you need to change the pump soon.

We did a pump change out on a friend and board member's (Tex2kZR2) 2002 ZR2 a few weeks ago. His was acting exactly how I describe above and he was having an intermittent problem of low idle, say around 500 rpm's and this was continuing after changing the fuel pump. His constant pressure was at about 52 psi which is on the very low side so it was better to just change it out instead of taking a chance. The job took about 3 hours to do and we removed the bed which is what I recommend instead of pulling the tank. It may be more of a pain to have to remove/reinstall the bed but it keeps you off of your back more and you just unhook the battery instead of having electrical crap hanging out all over the place after pulling the tank.