Humming/Vibration noice when pressing gas pedal

[Aesop]

Hello, I have a 2004 Chevy Express 1500 AWD 5.3 V8 with currently (01-07-2023) 161,xxx miles. I'm up here in Fairbanks, Alaska and the water pump was leaking like a sieve (from the weephole apparently) so i had that replaced at a local shop ($800) and I recently did the oil change myself.

Tonight, 01-07-2023, I left the house to go to Costco and and then drove back to the house and left it parked outside idling, when I got back in and put the gearshift into Drive, I started hearing this humming/vibrating noise that would get into higher rpm the harder I pressed the gas pedal. I quickly drove back to the house driveway and parked it for the night cause I didn't know what was going on. I tested it out again and with the van in Park, I pressed the gas pedal again and I still heard the noise. Does anyone know what may be causing this?

It is worth noting that on the repair order from the shop that did the water pump, they used their scanner to see what the codes were and there were these codes:
P0101 - Mass Air Flow
P0106 - Map or baro Circuit out of range
P0108 - MAp or Baro press signal high
P0430 - Catalyst Eff Low Bank 2

A previous mechanic told me that these types of codes are just O2 sensor codes and it is not worth dropping the gas tank just to get them, but the shop that did the water pump laughed at that and said no that could cause a bunch of other problems.

I was told by some people I asked tonight that it could be a misfire and to possibly check the spark plugs (and get new ones) and also coil packs? Also could be ice buildup in the wheels.

 

[Happy Camper]

You don't drop a fuel tank to fix an O2 sensor. If those were his exact words then I'm glad he's your previous mechanic.

If the wheels aren't moving, ice buildup on the wheels won't make noise.

Since you just had the water pump done, it could be that your serpentine belt isn't aligned properly on your pulleys. That could cause the sounds you're hearing. And they would be engine speed specific (faster most at faster engine speed/rpm). Maybe the serpentine belt wasn't routed correctly, but I would doubt that. It's possible one of the belt pulleys is going out. I would call the shop and mention the noise to them. Can you make a recording of the sound? Maybe make a video and upload it to YouTube, then look to it here.

Regarding your codes. I would fix/clean/replace your mass airflow sensor. If your lucky, that will fix the remaining codes. All the other codes can be triggered by a map sensor that isn't working properly.

Spark plugs and coil packs being bad would present in a completely different way. With different codes as well.

 

[bullfrog]

Since it does it both while parked and while driving most likely it is not the drive train. Motor or torque converter are your most likely areas to look. Have you looked in the front of the engine to see is any debris has gotten in the belt and it is running true with the engine running? Can you physically see the engine vibrating? Can you hear the noise and tell where it is coming from while looking in the engine compartment? Have the exhaust system checked as well as with the codes you have you may have a catalytic converter plugged or breaking up. They do make noises similar to a vacuum cleaner and the pieces vibrate inside when they go bad.

 

[Aesop]

Since it does it both while parked and while driving most likely it is not the drive train. Motor or torque converter are your most likely areas to look. Have you looked in the front of the engine to see is any debris has gotten in the belt and it is running true with the engine running? Can you physically see the engine vibrating? Can you hear the noise and tell where it is coming from while looking in the engine compartment? Have the exhaust system checked as well as with the codes you have you may have a catalytic converter plugged or breaking up. They do make noises similar to a vacuum cleaner and the pieces vibrate inside when they go bad.

YouTube link of the issue -



I was also advised it could be the power steering so I checked that and the power steering fluid was indeed low.

 

[Happy Camper]

That does sound like an empty steering system. It probably whines and complains more when you're turning at low or no speed.

Fill up the steering fluid to where it needs to be. Then with engine running, turn steering wheel all the way to one side then the other a few times. You do not have to push it at the very end. This is to get air out of the system.

If that's the problem, the noise level should go down immediately.

 

[Aesop]

That does sound like an empty steering system. It probably whines and complains more when you're turning at low or no speed.

Fill up the steering fluid to where it needs to be. Then with engine running, turn steering wheel all the way to one side then the other a few times. You do not have to push it at the very end. This is to get air out of the system.

If that's the problem, the noise level should go down immediately.

added some PS fluid to the reservoir and turned the van on. There was almost no noise this time. I turned the steering wheel all the way to the right and left so the fluid could push out the air. I then took video of some hose leaking under there, so now I know where it's leaking at. That explains the glistening fluid mess.

 

[Happy Camper]

How recently was your water pump done? Was there noise, or did you have any steering resistance prior to the work being done?

For a leak that bad, they should have seen that leak and at least let you know.

But at $800 to replace a water pump, I'm sure they would be willing to do the steering pump as well (sarcasm).

Sounds like some of the bad mechanics I dealt with years ago. Go in for one fix, and miraculously something else goes out within a reasonably quick time. Usually involving fluid loss. But never brake fluid lol.

I would call and ask how much to "fix" the problem. Then I would watch YouTube and fix the problem myself. Chances are it's something simple that might need to be tightened up or hose replaced.

It sounds like you have some questionable mechanics in your area. A lot of bad advice and diagnostics, except for the person that suggested steering.

 

[Aesop]

How recently was your water pump done? Was there noise, or did you have any steering resistance prior to the work being done?

For a leak that bad, they should have seen that leak and at least let you know.

But at $800 to replace a water pump, I'm sure they would be willing to do the steering pump as well (sarcasm).

Sounds like some of the bad mechanics I dealt with years ago. Go in for one fix, and miraculously something else goes out within a reasonably quick time. Usually involving fluid loss. But never brake fluid lol.

I would call and ask how much to "fix" the problem. Then I would watch YouTube and fix the problem myself. Chances are it's something simple that might need to be tightened up or hose replaced.

It sounds like you have some questionable mechanics in your area. A lot of bad advice and diagnostics, except for the person that suggested steering.

The water pump was done on Dec. 27th. It was leaking like a sieve, coming from the weephile apparently.

Well.. up here in Fairbanks, AK, when it was real cold out and then starting the van, I heard a noise similar to the noise in the video for a brief moment upon starting the van, but then it would go away real shortly. Just watch that -30F cold start video on my channel.

Apparently, up here in Fairbanks, Alaska it's semi-common for power steering to go out. That's probably why the Fairbanks area mechanic suggested it.

Yeah, I saw where the Ps fluid was leaking from and it loos to be just a hose/clamp. I took a video of it too.

Well, the mechanic in the l48 who said about not dropping the gas tank to replace an epa o2 sensor, sometimes they just do that to save you money.

 

[Happy Camper]

Well, the mechanic in the l48 who said about not dropping the gas tank to replace an epa o2 sensor, sometimes they just do that to save you money.

Just to be clear, I think a mechanic trying to save you money that you don't need to spend is a good, and rare, thing.

But a mechanic that says the headlight fluid doesn't need to be changed just because you have brake noise is either incredibly inept, really trying to avoid work they don't like, or are throwing words that don't belong together just to gauge your mechanical knowledge meter.

In any of the cases listed above, I would never trust them to work on my vehicle.

 

[mudbunny]

Same power steering problems in North Dakota. Three winters,three new pressure hoses. Amsoil full synthetic ps fluid has seemed to help.

 

[LargeMarge]

...2004 Chevy Express 1500 Fairbanks... water pump...oil change...humming/vibrating...would get into higher rpm the harder I pressed the gas pedal...with the van in Park, I pressed the gas pedal again and I still heard the noise...

It is worth noting that...

.
a)
Yes, 'it is worth noting that' you include an enormous amount of peripheral information... none addresses the probable source of your hum.
.
b)
If I was me, I would suspect cavitation.
You indicate humming related to RPM, non-related to road speed.
My first stop:
* verify levels of trans-fluid, hot, engine 'ON' and trans in neutral after driving, park brake 'ON', wheels blocked... as described in your op manual and Chilton-type guide for your year and model.
* verify levels of power-steering fluid, hot, engine 'OFF', park-brake 'ON', wheels blocked.
.
c)
Engine 'OFF', park-brake 'ON', wheels blocked.
Gloves 'OFF':
Feel around and under typical places of vibration:
* surpentine,
* fan
* accessories attached to the engine.
Gloves 'ON':
My diagnosis tools are my gloved hands, grab-n-shake everything I can reach.
Knock on everything with a wood mallet, watch for slop.
.
d)
Trans and power-steering, low fluid:
These two reservoirs contribute most hum, cavitating as the pump pulls air instead of fluid.
.
*** Advanced Only ***
Judicious use of a 3'/1m section of garden-hose is an invaluable tool for isolating noise.
Carefully place one end near your ear while you move the free end around the running engine.
If you are uncomfortable placing your hands near a running engine, do not do.
.
e)
A few remote potentials, down my usual list:
* surpentine belt frayed, a belt separating and flailing.
* alternator worn, bushings grinding.
.
As always, look at recent changes...
* your new (re-manufactured, re-built) water-pump could be mis-aligned
* your idler pulley could be sloppy.
.
f)
us$800 to R-n-R a water-pump sounds as though your Crack Repair Team needed most of a day to accomplish a twenty-minute job.
It happens...

 

[Aesop]

.
a)
Yes, 'it is worth noting that' you include an enormous amount of peripheral information... none addresses the probable source of your hum.
.
b)
If I was me, I would suspect cavitation.
You indicate humming related to RPM, non-related to road speed.
My first stop:
* verify levels of trans-fluid, hot, engine 'ON' and trans in neutral after driving, park brake 'ON', wheels blocked... as described in your op manual and Chilton-type guide for your year and model.
* verify levels of power-steering fluid, hot, engine 'OFF', park-brake 'ON', wheels blocked.
.
c)
Engine 'OFF', park-brake 'ON', wheels blocked.
Gloves 'OFF':
Feel around and under typical places of vibration:
* surpentine,
* fan
* accessories attached to the engine.
Gloves 'ON':
My diagnosis tools are my gloved hands, grab-n-shake everything I can reach.
Knock on everything with a wood mallet, watch for slop.
.
d)
Trans and power-steering, low fluid:
These two reservoirs contribute most hum, cavitating as the pump pulls air instead of fluid.
.
*** Advanced Only ***
Judicious use of a 3'/1m section of garden-hose is an invaluable tool for isolating noise.
Carefully place one end near your ear while you move the free end around the running engine.
If you are uncomfortable placing your hands near a running engine, do not do.
.
e)
A few remote potentials, down my usual list:
* surpentine belt frayed, a belt separating and flailing.
* alternator worn, bushings grinding.
.
As always, look at recent changes...
* your new (re-manufactured, re-built) water-pump could be mis-aligned
* your idler pulley could be sloppy.
.
f)
us$800 to R-n-R a water-pump sounds as though your Crack Repair Team needed most of a day to accomplish a twenty-minute job.
It happens...

Currently up here in Fairbanks, Alaska. AK and Hawaii where everything is slightly more expensive than the L48. Apparently, cause of how cold it gets here, the power steering going out/having problems is a really common occurence here.

I had to take back the van to the shop anyways cause I noticed evidence of coolant leaking (wasn't leaking currently, but there was evidence of the history of it leaking by where the hose clamps onto the water pump.) So they warranties all that water pump work they did out and afterwards they said it was some weird problem they've never seen before with the water pump, apparently they said it was leaking somewhere (can't remember exactly what they said currently)

The drive belt which was making a squeaking noise again cause the coolant was leaking onto it, presumably.

As for the power steering, they replaced the PS pressure line that goes to the PS pump from the (master Cylinder?) with an Arctic grade hose!