25K GM fuel pump humming. Is it failing?

[HawkeyeScott]

Bought a new MU1844 GM fuel pump in April 2020 for my 2008 Suburban. Installed that spring and has about 25K miles on it.

As of this weekend, it appears to have started making noise. Twice now I've turned the key on but not yet started the vehicle, and I hear what sounds like a climate control fan running from the back underneath side of the vehicle. (The climate control is off, btw.) Truck starts and runs fine. Based on sound and location, I'm assuming this is the fuel pump.

I replaced the original pump because it was making noise and, based on going fishing in some pretty remote places, I needed it to be reliable. Thus the Genuine GM part choice...

Besides monitoring it, is there anything I can/should be doing or checking?

I'd welcome thoughts...

 

[ZX11Rebel]

On the "GM" vehicles I've owned particularly pickups, they have always made a "whirring" noise when in operation. The original GM pumps went well over 200,000 plus before they quit. Now the aftermarket ones that I have bought that's a different story. They can be hit or miss in longevity sometimes.

 

[The_Eric]

Find a shop with a lab scope and have them record the waveform with it running. If there are any bad spots, they'll show up. It'll also show rpm (if they are going bad,the rpm will start to fall off. If they're using a low amp clamp, you can see the current draw as well. A bad pump won't draw the current that a healthy one will.

 

[stevejones]

In my experience with GM, it's when you don't hear a noise at KOEO you should be concerned....

 

[GMBoy]

Unfortunately, buying a "GM Pump" does not guarantee quality as they're just relabeled parts from various makers. You are not getting anything better then 90% of what's available on RA or on the store shelves. If you get the Advantage line that is the economy line and up one notch is Professional. Then it is OE which is as close to what came in your vehicle as possible. That is how they sell their parts now - good, better and best lol

 

[vwmaniaman]

A plugging up fuel filter may be causing it. Our VW vehicles have done that when the filter is getting clogged.

 

[Donald]

In the early days of GM fuel injection with TBI the in-tank fuel pumps would fail after running out or very low on gas. But your truck is newer than that.

A cell phone and AAA would seem a must-have in your situation.

 

[D60]

A plugging up fuel filter may be causing it. Our VW vehicles have done that when the filter is getting clogged.

'08 should be no filter other than at the pump intake itself. So, maybe, but you'd have to pull the pump anyway and I think it takes catastrophic events to clog those socks, like an inner tank liner peeling or sand/sugar etc

 

[Donald]

'08 should be no filter other than at the pump intake itself. So, maybe, but you'd have to pull the pump anyway and I think it takes catastrophic events to clog those socks, like an inner tank liner peeling or sand/sugar etc

Or PO ex wife.

 

[dogememe]

I've never owned a GMT900 but most of my GMT400s had whiny fuel pumps. Some louder than others but despite they supposed unreliability I never had ANY fuel pump issues on any of them. That said, if the noise suddenly changes (as in, it was silent before and now it's making an obvious noise) I'd say it's time to take a closer look.

 

[HawkeyeScott]

I've never owned a GMT900 but most of my GMT400s had whiny fuel pumps. Some louder than others but despite they supposed unreliability I never had ANY fuel pump issues on any of them. That said, if the noise suddenly changes (as in, it was silent before and now it's making an obvious noise) I'd say it's time to take a closer look.

Agree, and that’s where I’m at with this one right now. There was minimal sound before. You really had to work to notice it. When this showed up, I looked down at the climate control cluster to see if it was on and the blower cranked up. It is that noticeable. Something is different.

 

[HawkeyeScott]

Sorry, gotta own this. This is not a fuel pump issue.

I worked on pinning it down tonight to confirm it was coming from the tank. When I climbed in the back, I figured out it was in the ceiling, coming from near a little vent in the headliner.

It’s apparently part of the climate control system. It sounded like a fan because it apparently contains a small fan. “Cabin Air Temperature Sensor Aspirator” is its name. $40.

Feel dumb but am glad the fuel pump is good. After some other fuel pump issues on another car last fall, I was heading for ‘serenity now!’ territory.

Thanks to those who weighed in. Sorry for the false alarm.

 

[D60]

Sorry, gotta own this. This is not a fuel pump issue.

I worked on pinning it down tonight to confirm it was coming from the tank. When I climbed in the back, I figured out it was in the ceiling, coming from near a little vent in the headliner.

It’s apparently part of the climate control system. It sounded like a fan because it apparently contains a small fan. “Cabin Air Temperature Sensor Aspirator” is its name. $40.

Feel dumb but am glad the fuel pump is good. After some other fuel pump issues on another car last fall, I was heading for ‘serenity now!’ territory.

Thanks to those who weighed in. Sorry for the false alarm.

Now that you say this it brings back vague memories. I feel like I went through something similar on an '05 Yukon. But I could be wrong.....it's like remembering a dream that may or may not have happened. Diagnosis: CRS

 

[dfarr67]

Last three pumps I have installed have been Walbro 255 and two Denso's, I'm done with Delphi and acd.

 

[wtd]

I've never owned a GMT900 but most of my GMT400s had whiny fuel pumps. Some louder than others but despite they supposed unreliability I never had ANY fuel pump issues on any of them. That said, if the noise suddenly changes (as in, it was silent before and now it's making an obvious noise) I'd say it's time to take a closer look.

I changed out the original pump on my 98 Chevy K1500 when it had about 36,000 miles on it because it started getting very loud when it was on and I was afraid it was going out. I replaced it with an AC-Delco pump and that is what is still in it at almost 144,000 miles and it's still quiet.

 

[Dinoburner]

No worries here until it stops humming.

 

[Snagglefoot]

Sorry, gotta own this. This is not a fuel pump issue.

I worked on pinning it down tonight to confirm it was coming from the tank. When I climbed in the back, I figured out it was in the ceiling, coming from near a little vent in the headliner.

It’s apparently part of the climate control system. It sounded like a fan because it apparently contains a small fan. “Cabin Air Temperature Sensor Aspirator” is its name. $40.

Feel dumb but am glad the fuel pump is good. After some other fuel pump issues on another car last fall, I was heading for ‘serenity now!’ territory.

Thanks to those who weighed in. Sorry for the false alarm.

Did you ever bother changing out the Aspirator? I saw a few you tube videos and it wasn’t too bad. I was wondering if a new one would quiet it down.

 

[LDM]

Just replaced the pump in a 99 Suburban again with a brand new Delphi OEM pump after doing it 7 months ago because the pump decided to fail (did get it swapped under warranty at least). For some reason you can't hear this one run at all, even when it primes. I'm used to most of the GM pumps making a noise when priming. Hopefully this one actually lasts, seems like Delphi is all made in China garbage now. If it happens again I'm going aftermarket, probably Walbro as I've had good luck with them in high HP applications. I run a Walbro 255 in my 94 Z28 and I've never once had any issues with it.

 

[Fitz98]

On the "GM" vehicles I've owned particularly pickups, they have always made a "whirring" noise when in operation. The original GM pumps went well over 200,000 plus before they quit. Now the aftermarket ones that I have bought that's a different story. They can be hit or miss in longevity sometimes.

I had to replace mine at 135k miles on my 03. The pump was working fine, but I was having to crank a few times before it would start. I was told there is an integrated valve in the pump that was failing causing the fuel in the lines to drain back into the tank.

 

[Fitz98]

Did you ever bother changing out the Aspirator? I saw a few you tube videos and it wasn’t too bad. I was wondering if a new one would quiet it down.

I had this...sooooo annoying, especially the one that is right next to your ear. Funny how the internet seems to think these are little speakers. I changed the front one and it got quiet. A long time after, the back one started getting noisy. Replaced it when I re-did my headliner recently. All nice and quiet right now. Some videos I researched early on suggested you can just blow the dust out of the fan fins to quiet them down. I just replaced them with OE new.