: strange vaccum noise from 2000 lade

10-30-05, 04:44 PM
hey all. I am having this strange noise that can be heard while at idle sitting in the car. It sounds like a vaccum leak, or a pump running from in front of the dash. The noise also stays on for about four seconds after the engine is turned off. It can also be made by simply turning the key to the run position, then turning off. I was under the hood when my dad was turning the key, and it seems like the noise is coming from a component directly behind where the intake tube attaches to the manifold; directly behind the throttle body or whatever you want to call it. The component i suspect has two aluminum lines going into it. I don't have a maintenance manual yet, so that's the best description i can give. I'm not sure if this noise is normal or not, it just happened to be getting my ears attention lately. Maybe someone with a 2000 can try this with the radio off and stuff to see if you hear it is well. Like i said, it is quite apparent even with the truck at idle from inside. Any insight on what this may be and if it is normal or not? thanks.

11-01-05, 07:16 PM
The only noise I get is the fuel pump.

11-02-05, 01:15 PM
and you can hear in sucking like a vacuum from behnd the dash when idling with the radio off?

11-04-05, 12:40 AM
Not at all. The loudest noise I get is the alternator whine and cooling fan under the hood. Is your factory intake tubing securely attatche to the throttle body? If your check engine light isn't on and your engine, power brakes, and cruise control are working smoothly- a vac leak is unlikely. Sound to me like the factory intake silencer isn't secured to the throttle body- if this was removed a constant hiss sound is prominant naturally. Just a guess.

11-04-05, 11:11 AM
well, i just posted a reply with a test to this in the other thread, but i took off my intake tube to troubles shoot the other day, so i kno it is on, like i said, you don't have to have the engine running, just fuel pressure, check out the other topic of the new 2000 owner.

12-19-06, 02:13 PM
ck the fuel line going to the eng they might be rubbing the firewall