noise???
Thread Starter
Racer
Joined: May 2011
Posts: 281
Likes: 23
From: Harrison Arkansas
noise???
When my C-5 sits for a few hours or days, it has an engine noise when I start it then in a minute or two, it goes away. Sounds similar to a lifter problem but I don't think so...Do the LS1's have a polution pump or some kind of air pump that can be heard at the initial start-up?
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
When my C-5 sits for a few hours or days, it has an engine noise when I start it then in a minute or two, it goes away. Sounds similar to a lifter problem but I don't think so...Do the LS1's have a polution pump or some kind of air pump that can be heard at the initial start-up?
Yes, there is an air pump.
Thread Starter
Racer
Joined: May 2011
Posts: 281
Likes: 23
From: Harrison Arkansas
noise
It's a 2000 coupe, automatic...I've listened under the hood even with a stethoscope...can't seem to isolate it. It doesn't last very long, maybe one or possible two minutes. Just doesn't sound like a lifter that's why I'm suspecting an air pump. I had a C-4 with a noise the Chevy dealer couldn't (or wouldn't) find..I pulled the lifter cover and found one of the pushrods was not riding on the rocker completely and was scraping on the block. Chevy sprung for a new set of rods and sent a tech to my shop to install them. Back to my current problem...I didn't know if the 2000's had an air/smog type pump and if there were problems with it. The car has 68K miles.
Last edited by retired08; Nov 13, 2011 at 11:55 AM. Reason: add more info
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
It's a 2000 coupe, automatic...I've listened under the hood even with a stethoscope...can't seem to isolate it. It doesn't last very long, maybe one or possible two minutes. Just doesn't sound like a lifter that's why I'm suspecting an air pump. I had a C-4 with a noise the Chevy dealer couldn't (or wouldn't) find..I pulled the lifter cover and found one of the pushrods was not riding on the rocker completely and was scraping on the block. Chevy sprung for a new set of rods and sent a tech to my shop to install them. Back to my current problem...I didn't know if the 2000's had an air/smog type pump and if there were problems with it. The car has 68K miles.
Thread Starter
Racer
Joined: May 2011
Posts: 281
Likes: 23
From: Harrison Arkansas
Car sat all night in 70 degree weather. mobile 1 oil w/ about 2000 miles on it. Started it at idle..no engine noise, reved it to 15-1700 rpm..no obvious engine noise..(what the heck??). Back at idle..slight knock but it really sounds more like a pump of some type...then it goes away. I keep thinking emmissions or smog pump? does it have one? It just doesn't seem to be piston slap or a lifter. My "other" idea is that it may be in the exhaust...it has an X pipe with stock mufflers, a "cross-over" pipe between the two outlets and corsa tips. If it were an exhaust issue, I'd think it would take more time than one-two minutes for it to heat up and go away. My Toyota Tundra makes a noise similar to this when I start it...Tech guy said it was some type of air pump and a lot of them make the same noise.
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