HELP! Hissing sound after drilling though firewall

**Jomamma** · 02-03-2012

First let me start off by saying that I am new to the forums. I bought a brand new GTP Monday and I decided to register on the forums yesterday.

Today I decided that I would switch all of my old speakers/subs/headunit from my old grand prix to my new gtp. Having already done this in my old grand prix I decided to drill though the rubber grommet located under glove box. I made sure to stay away from the bundle of wires. While beginning to drill the the bit decided to go in an unintended direction and hit the bundle of wires. At the time I recall hearing a little bit of a hiss. I noticed that it was getting dark anyway and i decided to call it a day.

After cleaning up my car a bit I decided to take it for a run to hear the newly installed speakers. Immediately after starting it I noticed a hissing noise coming from where I drilled. The car still runs the same, and the AC/Heat work. However, I did noticed that it made different hissing noises when I changed the air conditioning from max, head, feet, defrost etc.

Please help! What is this noise! WHAT DID I DOOOOO!

**KeithGTP03** · 02-03-2012

What year is your car? Mine is an 03 and It has a vac line that runs the HVAC. This is on behind the center console on the passenger side. It runs from here through the grommet on the the passenger firewall and connects to the tree on the supercharger

**Jomamma** · 02-03-2012

I have a 97 2 door. I tried looking for the first picture but no luck. Where do I go from here.

**Jomamma** · 02-03-2012

Well thats what it is. I unplugged that vacuum line from the super charger tree and no hissing from inside. Where can i get a new vac line?

**simbah** · 02-03-2012

your local hardware store or auto parts store just take a sample with you and tell them you need that size and however long you want

**Swiggles** · 02-03-2012

You could probably just tape it up really well since its just a vac line for the hvac. Unless you cut it up really bad

**SlowNA06** · 02-03-2012

Originally Posted by Swiggles

You could probably just tape it up really well since its just a vac line for the hvac. Unless you cut it up really bad

See, here's the problem with that: that vacuum line connects to multiple spots and will cause issues. Fix it right the first time.

**KeithGTP03** · 02-03-2012

Originally Posted by SlowNA06

See, here's the problem with that: that vacuum line connects to multiple spots and will cause issues.

Its a straight line that runs from the tree to the HVAC. It doesnt connect to anything else. But I agree, fix it right. Get at least 8ft of vac line and rerun that line.

**Jomamma** · 02-03-2012

There's a chance that i may have also clipped some of the wires. Everything is working fine. Ill check to see if i hit anything in the morning.

**KeithGTP03** · 02-03-2012

Yeah, that would be a nightmare. Those wires are not easy to get to if they need replacing.

**Jomamma** · 02-03-2012

Originally Posted by KeithGTP03

Yeah, that would be a nightmare. Those wires are not easy to get to if they need replacing.

Tell me about it.

What are those wires for?

**SlowNA06** · 02-03-2012

Originally Posted by KeithGTP03

Its a straight line that runs from the tree to the HVAC. It doesnt connect to anything else.

Whut?

The vacuum manifold connects to no less than the intake, brake booster, and bypass valve vacuum actuator, as well as the HVAC.

**KeithGTP03** · 02-04-2012

Originally Posted by SlowNA06

Whut?

The vacuum manifold connects to no less than the intake, brake booster, and bypass valve vacuum actuator, as well as the HVAC.

Yes, but the HVAC line runs directly from the manifold to the HVAC. You can just cap off the HVAC port on the manifold and it wont affect anything. You'll just have issues switching levels on your heater/ac.

**KeithGTP03** · 02-04-2012

Originally Posted by Jomamma

Tell me about it.

What are those wires for?

I believe that they run to the fuse box in the glove box

**Jomamma** · 02-04-2012

Originally Posted by KeithGTP03

Yes, but the HVAC line runs directly from the manifold to the HVAC. You can just cap off the HVAC port on the manifold and it wont affect anything. You'll just have issues switching levels on your heater/ac.

I know that if I disconnect this line from the engine it will idle funny. The line cant be broken that bad because its idling fine.

**KeithGTP03** · 02-04-2012

Yeah, removing it without sealing off the port will introduce a big vac leak. Sounds like you just clipped it, but a vac leak is a vac leak. And it will get worse before it gets better.

**Jomamma** · 02-04-2012

Thanks for the help. There was only a small hole in the vac line so i patched it up with some tape. I got lucky. The whole process to checking the wires and reparing the hole took about 4 hours. I hated every frustrating moment of it...

**develand** · 02-05-2012

FYI, future reference, my 08 has that giant rubber piece too. I just taped my amp power wire to a plastic coat hanger, and pushed it through the existing hole....

**Jomamma** · 02-05-2012

Yeah that's what I did but I instead made a cut though one side of the boot and just fed it through there.

I forgot how load these subs were.

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