Help diagnose a (struggling?) pump sound?

[amongmany]

Ok, I know it's tough to diagnose sounds but I haven't managed to get a video/recording of this yet. Would appreciate any thoughts on where to start...

On cold start, I'm getting a sound that's a bit like a (struggling?) pump just in front of the driver in the lower left corner of the windshield. Can't tell if it's coming from the engine bay or behind the dash (I'd guess the engine bay). It seems to go away after driving for a few mins.

Any thoughts? I'll try to get a recording today.

 

[Commander AJ]

Ok, I know it's tough to diagnose sounds but I haven't managed to get a video/recording of this yet. Would appreciate any thoughts on where to start...

On cold start, I'm getting a sound that's a bit like a (struggling?) pump just in front of the driver in the lower left corner of the windshield. Can't tell if it's coming from the engine bay or behind the dash (I'd guess the engine bay). It seems to go away after driving for a few mins.

Any thoughts? I'll try to get a recording today.

Sounds like the SAIS pump, you can do a search to find instructions on how to disable it with a relay and some minor wiring. The pump is under the intake manifold so it's a pita to get to if it breaks and it could send foam bits and fan blades into the manifold from what I've read.

 

[amongmany]

Sounds like the SAIS pump, you can do a search to find instructions on how to disable it with a relay and some minor wiring. The pump is under the intake manifold so it's a pita to get to if it breaks and it could send foam bits and fan blades into the manifold from what I've read.

I'm hearing either SAIS or "brake pump" (brake master cylinder?). Any easy way to determine which it might be?

 

[amongmany]

Judging from the YT video in the first post here, this is NOT what I'm hearing. I'm getting an intermittent grinding/pumping sound, not a loud vacuum cleaner type of whir.

EDIT: I have an '04, so definitely not SAIS (wasn't added till '05)

 

[Sgn2bapt]

I'm intrigued

 

[amongmany]

I'm intrigued

Me too. I tried to get a recording of it, but it didn't happen on startup. Seems intermittent. Going to keep trying.

 

[trd4x4]

I get a noise in that area occasionally that I think has to do with ac/temp servos and mixing valves? I remember reading another thread and somebody changed these valves and took care of the problem. Noticed if I switch temp control to max hot or cold it goes away. Not sure if it’s the same noise you’re hearing.

 

[amongmany]

I get a noise in that area occasionally that I think has to do with ac/temp servos and mixing valves? I remember reading another thread and somebody changed these valves and took care of the problem. Noticed if I switch temp control to max hot or cold it goes away. Not sure if it’s the same noise you’re hearing.

Thanks, I'll play with that and see if it triggers anything. So far, I can't find causation.

 

[Sgn2bapt]

Seems like @dnp had a similar problem with his servos or mixing valves, we may be able to get him to chime in.

 

[dnp]

Yeah, I changed all of my servos, and my sounds went away. However, mine were “electronic “ sounds and clicking. They didn’t sound anything like the description here. Also, mine were clearly coming from areas right of the driver’s footwell and rightward over to the far right side of the truck.

In your case, my money would be on the brake contraption. It’s located where you stated, and it can make noises like you describe. Just be sure to do something about it before it goes out. No brakes is not a good thing to experience!

 

[SBANGLICO]

The electronic brake pump/master for the rear brakes energizes on startup, totally normal.

Just turn the key to on and listen and wait, without starting the GX. You will hear the system come on for several seconds then stop. If you didn't hear it you would have little to no rear brakes and the ABS/TRAC would also be out.

You can also pop the hood, the master cylinder is right where you describe the noise.

 

[amongmany]

I managed to get a recording of the sound. Happens at startup (more on a cold start) and seems to go away after driving for a few mins.

Here's the video:

 

[amongmany]

The electronic brake pump/master for the rear brakes energizes on startup, totally normal.

Just turn the key to on and listen and wait, without starting the GX. You will hear the system come on for several seconds then stop. If you didn't hear it you would have little to no rear brakes and the ABS/TRAC would also be out.

You can also pop the hood, the master cylinder is right where you describe the noise.

Thanks — I'm new to the platform and still getting used to all the sounds. Just trying to figure out what's normal vs. concerning (esp. with nearly 200k on the clock).

 

[dnp]

I still bet it's the brake pump, but as @SBANGLICO suggested, try getting a recording from under the hood WITHOUT starting the engine.

Open the hood, and open the driver's door. Stand in the door opening and hold your phone (or whatever recording device) over into the engine bay, and then turn your key to on (without starting the engine). If there's a noise of any concern, it will be in the engine bay, and not under the dash. That will be the easiest way to (a) determine the location of the sound, and (b) assess its severity (if any at all).

My thoughts......................

 

[amongmany]

I still bet it's the brake pump, but as @SBANGLICO suggested, try getting a recording from under the hood WITHOUT starting the engine.

Open the hood, and open the driver's door. Stand in the door opening and hold your phone (or whatever recording device) over into the engine bay, and then turn your key to on (without starting the engine). If there's a noise of any concern, it will be in the engine bay, and not under the dash. That will be the easiest way to (a) determine the location of the sound, and (b) assess its severity (if any at all).

My thoughts......................

Makes sense — will do. So it sounds potentially problematic to you?

 

[dnp]

Makes sense — will do. So it sounds potentially problematic to you?

I could barely hear it. I couldn't tell what it was or where it came from........so, at this point, I couldn't give an opinion

 

[amongmany]

I could barely hear it. I couldn't tell what it was or where it came from........so, at this point, I couldn't give an opinion

I'll aim to get a better recording with the hood open later today.

 

[obasan]

figure out the issue/non-issue?

 

[amongmany]

figure out the issue/non-issue?

No, I actually haven't yet. When I originally posted this, I tried multiple times to get a better recording of the sound and it didn't happen. It has happened again occasionally, but outside of popping the hood every time I go to start the truck, it's difficult to capture.

 

[obasan]

I do hear a noise when i first start up the car (cold start) that disappears in a bit. Actually now that I hear yours i believe its the same (noise towards the end of your video). Eh. Not sure.