Air Pump woes....
Thread Starter
Pro
Joined: Feb 2007
Posts: 608
Likes: 70
From: Richmond, VA
Air Pump woes....
Morning all. I recently started noticing a strange sound when I started my car cold. The noise is hard to describe, but reminded me of a duck call. Lol.
Anyhow, I narrowed it down to the air injection pump by removing the small hose from my intake(K&N) right after a cold start. The noise was definitely coming from that air hose. Additionally, a few days later I through a P0410 code.
Here's my question. The pump was still providing some suction. Weather it was enough, I wouldn't know. I would think an electric air pump would either fail or not. Agreed? Has anyone else encountered this weird noise related to the air pump and come to a resolution?
Help!
Anyhow, I narrowed it down to the air injection pump by removing the small hose from my intake(K&N) right after a cold start. The noise was definitely coming from that air hose. Additionally, a few days later I through a P0410 code.
Here's my question. The pump was still providing some suction. Weather it was enough, I wouldn't know. I would think an electric air pump would either fail or not. Agreed? Has anyone else encountered this weird noise related to the air pump and come to a resolution?
Help!
Instructor
Joined: May 2010
Posts: 179
Likes: 4
From: Little Compton, RI
Morning all. I recently started noticing a strange sound when I started my car cold. The noise is hard to describe, but reminded me of a duck call. Lol.
Anyhow, I narrowed it down to the air injection pump by removing the small hose from my intake(K&N) right after a cold start. The noise was definitely coming from that air hose. Additionally, a few days later I through a P0410 code.
Here's my question. The pump was still providing some suction. Weather it was enough, I wouldn't know. I would think an electric air pump would either fail or not. Agreed? Has anyone else encountered this weird noise related to the air pump and come to a resolution?
Help!
Anyhow, I narrowed it down to the air injection pump by removing the small hose from my intake(K&N) right after a cold start. The noise was definitely coming from that air hose. Additionally, a few days later I through a P0410 code.
Here's my question. The pump was still providing some suction. Weather it was enough, I wouldn't know. I would think an electric air pump would either fail or not. Agreed? Has anyone else encountered this weird noise related to the air pump and come to a resolution?
Help!
I had to have new check valves put on my car to clear P0410 and got the same noise after they were installed, i thought it was the air pump as well.
Next to the altenator there is a connector that splits the line from the air pump to the check valves. Unplug it, if my guess is correct, you will hear the noise from the check valves side of the line and if you block this side solid the noise will go away. The gurgle / duck call sound simply transmits through the hose and emminates at the air filter.
I'm not sure what the cure is for mine, the dealer insists they used the correct check valve and i insist that the noise didnt exsist prior to the valve change.
maybe someone else out there knows the fix.
Thread Starter
Pro
Joined: Feb 2007
Posts: 608
Likes: 70
From: Richmond, VA
Ok. I just went to the garage, and unplugged the hose at the connection by the alternator, and fired it up.
The hose going to the air pump, was the one the duck call noise was coming from. Additionally, there wasn't much air being pushed through the line. The air pump itself sounded normal(high pitched whistle). I'm wondering if some type of restriction magically appeared in the line coming from the pump to that connection near the alternator? Or, ive read there is a valve at the pump that sometimes fails too.
Thoughts?
The hose going to the air pump, was the one the duck call noise was coming from. Additionally, there wasn't much air being pushed through the line. The air pump itself sounded normal(high pitched whistle). I'm wondering if some type of restriction magically appeared in the line coming from the pump to that connection near the alternator? Or, ive read there is a valve at the pump that sometimes fails too.
Thoughts?
Instructor
Joined: May 2010
Posts: 179
Likes: 4
From: Little Compton, RI
Ok. I just went to the garage, and unplugged the hose at the connection by the alternator, and fired it up.
The hose going to the air pump, was the one the duck call noise was coming from. Additionally, there wasn't much air being pushed through the line. The air pump itself sounded normal(high pitched whistle). I'm wondering if some type of restriction magically appeared in the line coming from the pump to that connection near the alternator? Or, ive read there is a valve at the pump that sometimes fails too.
Thoughts?
The hose going to the air pump, was the one the duck call noise was coming from. Additionally, there wasn't much air being pushed through the line. The air pump itself sounded normal(high pitched whistle). I'm wondering if some type of restriction magically appeared in the line coming from the pump to that connection near the alternator? Or, ive read there is a valve at the pump that sometimes fails too.
Thoughts?
I just did the garage thing with mine as well and on startup i dont hear the noise, the airpump is doing its thing and pushing air thru the checkvalves. my noise appears after the air pump cycle is finished and there is no air going through, its exhaust noise coming back through the new check valves.
Check out this thread, it has a great set of pictures of the air pump and the second valve you mention.
http://forums.corvetteforum.com/c5-t...eck-valve.html
Thread Starter
Pro
Joined: Feb 2007
Posts: 608
Likes: 70
From: Richmond, VA
I just jacked up my car, took off the little access panel, and unplugged the hose AFTER the valve on the end of the air pump. Started the car, and still and very little air flow. So I shut her down, and took the valve off completely. Started her up again, and wouldn't ya know it....a strong steady stream of air.
So, either that valve is bad, or the vacuum line going to it is. I can't feel any cracks in the line, but only a few inches of it are exposed before it goes in to a wire loom and disappears. I wonder where the other end is?
So, either that valve is bad, or the vacuum line going to it is. I can't feel any cracks in the line, but only a few inches of it are exposed before it goes in to a wire loom and disappears. I wonder where the other end is?
Instructor
Joined: May 2010
Posts: 179
Likes: 4
From: Little Compton, RI
Interesting, i'll check mine.
Question, when you unplug the hose at the altenator, can you hear any exhaust gurgle from the check valve side of the line.
I didnt have my noise prior to the check valves being replaced to clear P0410 but who know's what else the dealer might have done. When i picked up the car before i ever got off the lot P0410 re appeared (bad check valve they say). I left the car and they said they replaced the just replaced rt bank valve but ive wondered ever since if they did something else. In my checking to clear P0410, i had a good air flow from the pump before the dealer worked on the car, after they were done the air flow was 2x as much. Now i'm wondering if they did something wth the valve at the air pump allowing the noise to migrate through the air pump.
Could you check your car and see if you hear the noise from the check valve side for me?
Question, when you unplug the hose at the altenator, can you hear any exhaust gurgle from the check valve side of the line.
I didnt have my noise prior to the check valves being replaced to clear P0410 but who know's what else the dealer might have done. When i picked up the car before i ever got off the lot P0410 re appeared (bad check valve they say). I left the car and they said they replaced the just replaced rt bank valve but ive wondered ever since if they did something else. In my checking to clear P0410, i had a good air flow from the pump before the dealer worked on the car, after they were done the air flow was 2x as much. Now i'm wondering if they did something wth the valve at the air pump allowing the noise to migrate through the air pump.
Could you check your car and see if you hear the noise from the check valve side for me?
Thread Starter
Pro
Joined: Feb 2007
Posts: 608
Likes: 70
From: Richmond, VA
I checked, and do indeed hear an exhaust gurgle from the side going to the check valves. I would presume this sound is normal.
I ordered a replacement valve from my local stealership for $60. It'll be here Monday, and I'll post my results. The only other possibility in my situation would be the vacuum line, but it appears to be ok. Other than the few inches of exposed line near the pump itself, it's protected by a wire loom.
I ordered a replacement valve from my local stealership for $60. It'll be here Monday, and I'll post my results. The only other possibility in my situation would be the vacuum line, but it appears to be ok. Other than the few inches of exposed line near the pump itself, it's protected by a wire loom.
Instructor
Joined: May 2010
Posts: 179
Likes: 4
From: Little Compton, RI
I checked, and do indeed hear an exhaust gurgle from the side going to the check valves. I would presume this sound is normal.
I ordered a replacement valve from my local stealership for $60. It'll be here Monday, and I'll post my results. The only other possibility in my situation would be the vacuum line, but it appears to be ok. Other than the few inches of exposed line near the pump itself, it's protected by a wire loom.
I ordered a replacement valve from my local stealership for $60. It'll be here Monday, and I'll post my results. The only other possibility in my situation would be the vacuum line, but it appears to be ok. Other than the few inches of exposed line near the pump itself, it's protected by a wire loom.
I checked my Manuals and they refer to the valve in question at the air pump as 2ndary AIR shut off valve., This is controlled by the AIR solenoid valve which is under the battery accessed via the filer pannel in the right front wheelwell, thats where the vacuum hose goes.
Did the dealer say what the purpose of the shutoff valve is? air pressure shut off from pump or air / noise shutoff from check valve?
Since the pump and shutoff valve are electrically activated by the PCM, i'm now wondering if my valve is stuck open and this is what is allowing the gurgle noise to migrate thru the pump being heard at the air filter.
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Thread Starter
Pro
Joined: Feb 2007
Posts: 608
Likes: 70
From: Richmond, VA
You're welcome. I didn't ask the dealer any questions, just ordered the part. He didn't seem like he was in a very helpful mood anyhow. I'll follow up on Monday after I install the new part.
Thread Starter
Pro
Joined: Feb 2007
Posts: 608
Likes: 70
From: Richmond, VA
Ok. I replaced the check valve at the air pump this morning, and problem solved. Air flows freely when the pump is on, and the noise is gone.
The part# for this check valve is 1255-8524. It's available only through GM. Napa showed a part fitting my description, but it was not the right one.
Hope this helps someone!
The part# for this check valve is 1255-8524. It's available only through GM. Napa showed a part fitting my description, but it was not the right one.
Hope this helps someone!
