Hissing

toothpick · February 15, 2011

Any chance it's a vacuum leak from the power brake booster...try pumping the brakes with the engine running and see if the sound changes. ??

I actually tried pushing the brake immediately after releasing the accelerator pedal, the noise goes away. Am scheduled for service first thing in morning.

bud4ya · February 15, 2011

Let me know what they say. Yesterday was in the high 30's low 40's and I still got the hissing when I accelerate

Any chance it's a vacuum leak from the power brake booster...try pumping the brakes with the engine running and see if the sound changes. ??

I actually tried pushing the brake immediately after releasing the accelerator pedal, the noise goes away. Am scheduled for service first thing in morning.

toothpick · February 16, 2011

Let me know what they say. Yesterday was in the high 30's low 40's and I still got the hissing when I accelerate

Any chance it's a vacuum leak from the power brake booster...try pumping the brakes with the engine running and see if the sound changes. ??

I actually tried pushing the brake immediately after releasing the accelerator pedal, the noise goes away. Am scheduled for service first thing in morning.

Tech said he didn't even hear the noise, even though I was in the truck with him, trying to point out the sound. All he said he could hear was "wind noise", which I know is not the noise I am hearing.

They ran a check, no codes, no updates available.

I left the dealership, went to car wash, left out of car wash, and bam!!! The noise is there, as loud as every. So at any rate I told the tech, well since no codes or anything, I'll run the shit out of it until it dyes, then bring it in when i comes apart. It'll be up to you guys to try and put it back together while it's under warranty.

Fair enough, I realize if the tech doesn't hear the noise, he can't address it. I realize you just can't go changing parts. Just frustrating situation. And FYI, it doesn't seeem like the brakes have anything to do with the sound, this is sounding like valve train, air leak, vacuum leak, or some type of pressure release......

pm26 · February 16, 2011

N O R M A L !!!!!!!!

Actually, on my truck there is a slight hissing noise every time I push on the brake pedal. This is according to GM, NORMAL.

snarkee · February 16, 2011

N O R M A L !!!!!!!!!!!

Actually, on my truck there is a slight hissing noise every time I push on the brake pedal. This is according to GM, NORMAL.

mine is ONLY on acceleration.....pressing the brakes has no effect

i am just chalking it up to hearing excess engine noise as the result of shitty firewall insulation

o well

bud4ya · February 16, 2011

I think most of us get it when hitting the gas.

N O R M A L !!!!!!!!!!!

Actually, on my truck there is a slight hissing noise every time I push on the brake pedal. This is according to GM, NORMAL.

bud4ya · February 16, 2011

Thanks for the update. I wil get mine in soon and see what they say.

Let me know what they say. Yesterday was in the high 30's low 40's and I still got the hissing when I accelerate

Any chance it's a vacuum leak from the power brake booster...try pumping the brakes with the engine running and see if the sound changes. ??

I actually tried pushing the brake immediately after releasing the accelerator pedal, the noise goes away. Am scheduled for service first thing in morning.

Tech said he didn't even hear the noise, even though I was in the truck with him, trying to point out the sound. All he said he could hear was "wind noise", which I know is not the noise I am hearing.

They ran a check, no codes, no updates available.

I left the dealership, went to car wash, left out of car wash, and bam!!! The noise is there, as loud as every. So at any rate I told the tech, well since no codes or anything, I'll run the shit out of it until it dyes, then bring it in when i comes apart. It'll be up to you guys to try and put it back together while it's under warranty.

Fair enough, I realize if the tech doesn't hear the noise, he can't address it. I realize you just can't go changing parts. Just frustrating situation. And FYI, it doesn't seeem like the brakes have anything to do with the sound, this is sounding like valve train, air leak, vacuum leak, or some type of pressure release......

bud4ya · February 16, 2011

Snarkee can you tell me the make and part number for your side steps. I have not bought a pair yet because I saw the straight ones like you have and like them better. Just having a hard time finding them. The Westin Plat Oval are everywhere. I was going to get those but then decided I want the straight cut like you have.

Thanks

N O R M A L !!!!!!!!!!!

Actually, on my truck there is a slight hissing noise every time I push on the brake pedal. This is according to GM, NORMAL.

mine is ONLY on acceleration.....pressing the brakes has no effect

i am just chalking it up to hearing excess engine noise as the result of shitty firewall insulation

o well

snarkee · February 16, 2011

not sure the number but they are the GM accessory 6inch ovals

bud4ya · February 16, 2011

Ok those are the ones I looked at from the dealer but if I remember correctly they were like $600 and change. Trying to find westin ones like that. I found Westin part number 22-5040 but now I can't find teh dam mounting kit.

Thanks

not sure the number but they are the GM accessory 6inch ovals

snarkee · February 17, 2011

So I determined that my hissing is related to my charging system. I experimented with regular mode and tow haul mode. At the same rpms in tow haul mode the hissing is very noticeable while in regular mode its quieter

With the truck running the batttery tested at 15.5v when I got home and shut the truck off, the battery

was 12.1

Next I put the headlamps on and turned the key to on with the truck off and within 30secs my battery rundown protection kicked in .

Next step is a load test

bud4ya · February 17, 2011

Thanks for this info and looking into it

So I determined that my hissing is related to my charging system. I experimented with regular mode and tow haul mode. At the same rpms in tow haul mode the hissing is very noticeable while in regular mode its quieter

With the truck running the batttery tested at 15.5v when I got home and shut the truck off, the battery

was 12.1

Next I put the headlamps on and turned the key to on with the truck off and within 30secs my battery rundown protection kicked in .

Next step is a load test

snarkee · February 18, 2011

well ive come to the conclusion that my noise is related to the charging system.....there is obviously a problem.....dealer said the battery was low so they charged it up for me

they blamed the low battery on the long stretch of cold weather, which I find as BS.....i drive my truck everyday and it was 50 degrees today plus ii drove the truck 100km.....the truck should have fully charged the battery in that time, yet when I shut it off, and put the key in the ON position, the low battery warning came on within 30 seconds

bud4ya · February 18, 2011

I am taking mine down today just to chat with them and make an appt. If a tech can take a quick ride I will let you know what he says. My buddy rode in teh truck today and he said man sounds like you already installed a S/C. I said oh ya that's it

well ive come to the conclusion that my noise is related to the charging system.....there is obviously a problem.....dealer said the battery was low so they charged it up for me

they blamed the low battery on the long stretch of cold weather, which I find as BS.....i drive my truck everyday and it was 50 degrees today plus ii drove the truck 100km.....the truck should have fully charged the battery in that time, yet when I shut it off, and put the key in the ON position, the low battery warning came on within 30 seconds

snarkee · February 18, 2011

I am taking mine down today just to chat with them and make an appt. If a tech can take a quick ride I will let you know what he says. My buddy rode in teh truck today and he said man sounds like you already installed a S/C. I said oh ya that's it

well ive come to the conclusion that my noise is related to the charging system.....there is obviously a problem.....dealer said the battery was low so they charged it up for me

they blamed the low battery on the long stretch of cold weather, which I find as BS.....i drive my truck everyday and it was 50 degrees today plus ii drove the truck 100km.....the truck should have fully charged the battery in that time, yet when I shut it off, and put the key in the ON position, the low battery warning came on within 30 seconds

funny tho, my truck made the noise all the way to the dealer but when i got there it stopped.....last week when towing the sleds my buddy asked me the same thing....he thought i had a leak of some sort