Head Lights and Noise

[08TR196]

This is a two part question..

First thing is I have a noise and I am trying to describe it. I happens when I initially start the vehicle and the volume deminishes as the engine comes to temp.. The middle of my temperater gauge. I thought it was the belt but now I don't. It sounds like a rattle snake if you have ever heard one in person, not a bang or a ping or a boom. More like a sh, sh, sh and like I said the volume decreases as the engine comes to normal temp. What might I check? I am thinking about just replacing the serpentine belt because in neutral one day I didn't hear it until I put it back in drive? what are your thoughts.?

Also how in the heck do the head lights work? I never turn anything on so in the day time there is no running lights and in the evening they come on automatically. Problem is I saw a truck like my with the lower head lamps on in th day time , my truck doesn't do that. I came into work at 4am this morning and the top head lamps were burning but not the bottom. How do you turn the lights off at night? why doesn't the bottom row illuminate?
What can I check??

Thanks in advance..

[Tdragone]

What year is your truck? And are you the original owner? I THINK there's a BCM program the dealer can apply to make the DRLs not turn on during the day. As for how to turn them off; for my 2002; if I hit the dome light button 4 times (on off on off) it turns the automatic headlight feature off and utilizes the switch on the dash only.

As for the bottom row illumination.. most chevy's run only 2 lights at a time unless you add diodes and relays for 4 or 6 light illumination. search this forum or ebay for "4 light mod" and you'll find some info.

[08TR196]

2000 chevy silverado 5.3liter

Thanks for the information..

[j cAT]

Originally Posted by 08TR196

This is a two part question..

First thing is I have a noise and I am trying to describe it. I happens when I initially start the vehicle and the volume deminishes as the engine comes to temp.. The middle of my temperater gauge. I thought it was the belt but now I don't. It sounds like a rattle snake if you have ever heard one in person, not a bang or a ping or a boom. More like a sh, sh, sh and like I said the volume decreases as the engine comes to normal temp. What might I check? I am thinking about just replacing the serpentine belt because in neutral one day I didn't hear it until I put it back in drive? what are your thoughts.?

Also how in the heck do the head lights work? I never turn anything on so in the day time there is no running lights and in the evening they come on automatically. Problem is I saw a truck like my with the lower head lamps on in th day time , my truck doesn't do that. I came into work at 4am this morning and the top head lamps were burning but not the bottom. How do you turn the lights off at night? why doesn't the bottom row illuminate?
What can I check??

Thanks in advance..

the daytime running lamps fail at a high rate. replace these with the LL long life lamp.

headlamps come on automaticly. if you hit the push button for the interior lamps by the headlamp switch 2X rapidly the headlamps will go to manual mode ..on shut down this resets to auto mode..

most likely the noise on start up is the idler pulley or tension pulley bearings...with a hose one end stuck in your ear the other to probe for location of noise you will find this..