NPP issues
Thread Starter
Drifting
Joined: May 2006
Posts: 1,709
Likes: 18
From: Montgomery Il.
It's easy to check the vacuum lines just hook-up a Mity-Vac at the engine connection if it holds vacuum with the engine off then you are good up to the solenoid. You can also use positive pressure to find a leak if needed.
I had the BCM checked by a local shop and it was functioning properly so with no leaks and a functioning computer it moved the focus back to the solenoid. I said earlier that I checked the solenoid on the bench and it was good when in fact it was sticking closed.
Anyway it's all good now and I learned a lot so it wasn't a complete waste of time.
I had the BCM checked by a local shop and it was functioning properly so with no leaks and a functioning computer it moved the focus back to the solenoid. I said earlier that I checked the solenoid on the bench and it was good when in fact it was sticking closed.
Anyway it's all good now and I learned a lot so it wasn't a complete waste of time.
Instructor
Joined: Oct 2001
Posts: 192
Likes: 0
From: San Diego CA
#5 Exhaust Tailpipe Flow Control Valve Solenoid. Picked one up at my local Chevy dealer part #325794609 $94.48 list they sold it to me for $67.31
This is the one behind the right taillight mentioned earlier in the post, did you need to remove both to work with it? Thanks
This is the one behind the right taillight mentioned earlier in the post, did you need to remove both to work with it? Thanks
Thread Starter
Drifting
Joined: May 2006
Posts: 1,709
Likes: 18
From: Montgomery Il.
#5 Exhaust Tailpipe Flow Control Valve Solenoid. Picked one up at my local Chevy dealer part #325794609 $94.48 list they sold it to me for $67.31
This is the one behind the right taillight mentioned earlier in the post, did you need to remove both to work with it? Thanks
This is the one behind the right taillight mentioned earlier in the post, did you need to remove both to work with it? Thanks
Yes on the both tail lights.
Burning Brakes
Joined: Feb 2010
Posts: 825
Likes: 20
From: Laplata Maryland
Good info,
I need to start troubleshooting my problem. I have a 2008 Billy Boat NPP which I installed several years ago. Last week I was at Sebring with the NCM HPDE, and when I got on the road to head home which is more then 900 miles. My exhaust was droning like a mad man, and I have my wife as a passenger, and not to mention my brakes noise. So I first switched out the fuses and checked my foot switch, which I have to open the exhaust values. Then I disconnected it and put it back to stock, exhausts values never move from full open. I was pushing my car really hard, just in the 3 afternoon secession. I went through a entire tank of fuel. I could tell by my exhaust tips that they were quite hot, so I'm leaning towards a melted vacuum line. I just need to find sometime this weekend look where the pipes go over the axles.
I need to start troubleshooting my problem. I have a 2008 Billy Boat NPP which I installed several years ago. Last week I was at Sebring with the NCM HPDE, and when I got on the road to head home which is more then 900 miles. My exhaust was droning like a mad man, and I have my wife as a passenger, and not to mention my brakes noise. So I first switched out the fuses and checked my foot switch, which I have to open the exhaust values. Then I disconnected it and put it back to stock, exhausts values never move from full open. I was pushing my car really hard, just in the 3 afternoon secession. I went through a entire tank of fuel. I could tell by my exhaust tips that they were quite hot, so I'm leaning towards a melted vacuum line. I just need to find sometime this weekend look where the pipes go over the axles.
Burning Brakes
Joined: Feb 2010
Posts: 825
Likes: 20
From: Laplata Maryland
So a vacuum leak in the NPP system itself would have the ECM increase fuel mixture? That's pretty sensitive, considering the sole reason is to actuate the the exhaust values. I'm not saying your wrong, but that would explain my fuel usage. But my fuel consumption was pretty steady for the most part during the 2 days. Except for the last afternoon only because I was WOT as much as possible. The inside of my exhaust tips weren't solid black, but were a dirty white grey look as if I may be baking my CATS. At least that's what I thought. I just need to get it up on my lift. Today I'm off to get a crown, tomorrow I'm helping a friend who is going through cancer treatments. But I'm free this weekend, Thanks for you input
Instructor
Joined: Feb 2005
Posts: 139
Likes: 0
From: Los Angeles CA
Solenoid also
My symptoms started as if my NPP actuators were sticking.
They would open when they were supposed to,however they would stay on(in loud mode) until I shut the car off.
Then they would be fine(stay closed)until I went past 3500 RPM.
I have an 08 Z06 and it ended being the Exhaust Intake manifold vacuum solenoid part No. 25794609.
Thanks all.
They would open when they were supposed to,however they would stay on(in loud mode) until I shut the car off.
Then they would be fine(stay closed)until I went past 3500 RPM.
I have an 08 Z06 and it ended being the Exhaust Intake manifold vacuum solenoid part No. 25794609.
Thanks all.
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Drifting
Joined: Nov 1999
Posts: 1,502
Likes: 12
From: Yorktown Heights NY
Sorry this took so long but things kept popping up around the house that came first. Long story short it was the #5 Exhaust Tailpipe Flow Control Valve Solenoid. Picked one up at my local Chevy dealer part #325794609 $94.48 list they sold it to me for $67.31 which I thought was fair. Have your VIN number handy because there are two numbers for this part.
