Grinding Noise At Cold Start

[SmittyLogic]

Hi All,

Looking for some help with this grinding noise that happens when I start my '15 Tahoe LTZ. From what I can tell it only happens when the car is cold, if I run into a store quick and start it up after driving, it doesn't do it. Also, if I start it with remote start and let it idle, it still doesn't make this noise until I push start it and all functions turn on.

It's coming from the rear of the vehicle, thinking it has to be suspension related. I'm wondering if it isn't my Suspension Leveling Compressor?

Any thoughts? Appreciate the time.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

Would you be able to record the sound and post it here, or link it from a YouTube post, so that we hear what you are experiencing? It would be easier for us to help you diagnose, if we could hear the sound as well.

 

[SmittyLogic]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

Would you be able to record the sound and post it here, or link it from a YouTube post, so that we hear what you are experiencing? It would be easier for us to help you diagnose, if we could hear the sound as well.

I thought the video would attach to my original post, I uploaded it to YouTube.

 

[Joseph Garcia]

I thought the video would attach to my original post, I uploaded it to YouTube.

Wow! I'm not sure what that sound could be, but other members of this Forum much more knowledgeable than me in this area will chime in.

 

[Doubeleive]

I thought the video would attach to my original post, I uploaded it to YouTube.

does it do it non-stop? or did you end the video early? if it stops on it's own within 30 seconds then it's probably the air pump, since it is that loud you should be able to determine the exact source with ease, the pump is located right behind the rear drivers side wheel so........

 

[SmittyLogic]

It only does it for the length shown in the video, it's not constant, and it starts/stops on it own after start up.

 

[Doubeleive]

It only does it for the length shown in the video, it's not constant, and it starts/stops on it own after start up.

it's most likely the air pump, stand by the rear drivers wheel when you start it up, the pump is mounted to the frame right there by the rear wheel. the pump could be burning out if the rear shocks are leaking so check those out as well.

 

[SmittyLogic]

Is that part of the 'leveling' kit? Is the back end supposed to adjust up or down? Any idea how much one of those plus replacement costs? I had the front shocks done for about $1,800....I really don't want another of those bills. But I suppose it comes with the territory on a 9 year old toy hauler.

 

[wjburken]

Is that part of the 'leveling' kit? Is the back end supposed to adjust up or down? Any idea how much one of those plus replacement costs? I had the front shocks done for about $1,800....I really don't want another of those bills. But I suppose it comes with the territory on a 9 year old toy hauler.

You can get a compressor for $250 on RockAuto.

Rear air shocks are $300 a piece.

Takes about an hour to swap them all out.

 

[C1E2]

That's the air pump for sure. Mine had that same sound when I bought it and it took a while to figure out what it was. Replacement was quick and easy. I didn't the rear shocks at the same time. Unfortunately that didn't fix the rough ride issues I'm having but it did make the pump quiet again. If I even hear the pump it's only for 5 or 10 seconds...