check valves on 94?
Thread Starter
Burning Brakes
Joined: Nov 2002
Posts: 895
Likes: 3
From: Washington MO
check valves on 94?
Has anyone had to replace the check vavles on an lt1? My main concern is the check valve right behind and just above the intake - just in front of the firewall. My car has a pop-pop-pop sound and my mechanic said he thought it was coming from this check vavle. He used stethascope(sp)? and found it that way. Just wondering if anyone else may have had a similar experience? Thanks Zane
Melting Slicks
Joined: May 2001
Posts: 2,143
Likes: 7
From: San Diego CA
Re: check valves on 94? (94redrag)
Zane (good name, my Grandson is a Zane!),
My car makes the same kind of noise. As far as I can tell it always has. It's got 160K miles so far.
I don't understand what check valve you are talking about. What is it "checking"? Are you refering the the EGR plumbing? If so, I wouldn't worry about it unless you are having idling problems.
My car makes the same kind of noise. As far as I can tell it always has. It's got 160K miles so far.
I don't understand what check valve you are talking about. What is it "checking"? Are you refering the the EGR plumbing? If so, I wouldn't worry about it unless you are having idling problems.
Thread Starter
Burning Brakes
Joined: Nov 2002
Posts: 895
Likes: 3
From: Washington MO
Re: check valves on 94? (John Row)
John,
Dang! I thought I was the only Zane!
I'm refering to the check valve that sits between the intake plemun(sp?) and the firewall. Its sits just above and the intake, is black and has a piece of rubber hose that comes off of it and goes to the left side of the engine.My mechanis called it a "anti-backfire check vavle"
Maybe this is just the nature of the beast!? Zane
Dang! I thought I was the only Zane!
I'm refering to the check valve that sits between the intake plemun(sp?) and the firewall. Its sits just above and the intake, is black and has a piece of rubber hose that comes off of it and goes to the left side of the engine.My mechanis called it a "anti-backfire check vavle"
Maybe this is just the nature of the beast!? Zane
Safety Car
Joined: Feb 2002
Posts: 4,212
Likes: 10
From: Sun City West Az
Re: check valves on 94? (94redrag)
There are 2 check valves and they both belong to the AIR system. When the air pump is in operation during open loop, air is pumped into the exhaust manifolds to help heat up the converters. The black items you are refering are the check valves to prevent backfires into the AIR system. You can test them by pulling them out. Air should flow in the outbound direction (toward the exhaust manifold). If you can draw air backwards through them, they are defective.
