strange buzzing sound at startup?

**Poppn** · 05-09-2008, 06:24 PM

So I have had the car now for about a week (99 Camaro SS), and have noticed that on some startups, there seems to be some kind of accessory that turns on (kind of like when an A/C compressor kicks on) and it buzzs or vibrates at idle. It sounds like its towards the rear of the engine. Anything other than idle and you can't hear it.

It lasts for about 20-30 seconds or so, and when it "shuts off" you can here something kind of like wind down quickly to a stop.

Does it when the car is cold/warm, usually 9/10 starts you can here it.

wtf is it? Is there some kind of fan kicking on that I don't know about? I'm new to the LS1.

Thanks in advance, sorry if I sound crazy!!

**Cutlass** · 05-09-2008, 06:34 PM

Sounds like you are completely CRAZY!!! J/K...its probablly a bad secondary air injection pump or A.I.R. pump. Does it kinda sound like a jet engine taking off?? Anyways its mounted to the lower left front of the engine Compartment and probablly has a bad bearing. To fix the noise usually requires pump replacement.

**Poppn** · 05-09-2008, 06:58 PM

that may be it, but tonight I seemed to have pinpoint the sound. its definitely on the drivers side somewhere near the exhaust manifold.

I think.

Could it possible be the power steering pump? What happens if there is low fluid in it?

The car only has 49,000 miles on it, and it drives silky smooth, besides a slight wheel alignment problem.

**Cutlass** · 05-09-2008, 07:16 PM

Well...yeah I've had P/S pumps whine bad on cold starts when they are low on fluid. Top that fluid off and cold start the next day to see if the noise is gone. If so then it time to go looking for a P/S fluid leak.

**Poppn** · 05-09-2008, 07:31 PM

is there anything else it could be?

on my way over to my girlfriends house, I stopped the car and shut it off in her driveway. I waited about 20 seconds and then started the car back up. the sound was there again, but only for a certain amount of time, about 5-10 seconds.

I'm just confused because I have no idea what would rattle/buzz/whine only at a startup and then never again until the next startup?

**Poppn** · 05-09-2008, 08:02 PM

i did some googling and found a whole article about the LS1. In it I found this:

"There is an electric air injection reactor (AIR) pump that runs after start-up for a short length of time set by the PCM."

That sounds like what is turning on like you said, and then it shuts off after the certain period of time.

The sound is noticeable, but not like a "jet engine". Should it be something I need to worry about? Will it cause any problems in the long run? I still need to go for an emissions test in the next few weeks.

**Rhinohuey** · 05-09-2008, 10:40 PM

+1 for AIR pump

**KyleLs1** · 05-09-2008, 10:59 PM

Originally Posted by Rhinohuey

+1 for AIR pump

yep, you don't need it... you can remove all the air stuff and the egr stuff and just get the codes tuned out.

**SteveC** · 05-10-2008, 04:22 AM

It could be the fuel pump buzz when you first turn the key on.

SteveC

**chuckie669** · 05-10-2008, 06:46 AM

Just curious. Does anyone have a pic of the engine bay with all that removed and tuned out? I know when I removed the AIR for plugs and stuff it made a huge difference in my engine bay.

**SeVeReDiStOrTiOn** · 05-10-2008, 07:55 AM

Originally Posted by Poppn

i did some googling and found a whole article about the LS1. In it I found this:

"There is an electric air injection reactor (AIR) pump that runs after start-up for a short length of time set by the PCM."

That sounds like what is turning on like you said, and then it shuts off after the certain period of time.

The sound is noticeable, but not like a "jet engine". Should it be something I need to worry about? Will it cause any problems in the long run? I still need to go for an emissions test in the next few weeks.

It's the AIR pump like Cutlass said....it's under the driverside headlight. You can either replace it or remove the whole AIR system and tune out the codes...depending on the emissions in your area.

**Poppn** · 05-10-2008, 08:07 AM

Alright, sounds good.

So in other words, if it dies out it's not an essential part to the operation of the engine?

I started it up this morning, and you could hear it running, but it was alot quieter than the other night. And then it shuts off.

How is it to get to?

**0rion** · 05-10-2008, 12:06 PM

not sure on the camaro's but on my formula it was a piece of cake. There was an access door underneath the car below the drivers side headlight that you dropped down and the air pump was right there.