Problems under the hood

[wallace]

Hi there guys I just recently joined up on the forum to see if anyone out there knew what was going on with my Tahoe or what the problem is....

Details...2001 Chevy Tahoe with 5.3L Vortec 2WD 165K

Last night I took a drive to the store and my brother turned on the a/c to the heat setting then I turned it off because it didn't need to be on. Any-who lol

Once I got to the store and shut the engine off I heard something running like a little fan motor or something and when I cam out of the store it was still going....So once I got home I shut her down popped the hood and something on the left side of the engine bay (Looking at it from the from) on the back firewall as this little motor cylinder thing that has lines running to the A/C condenser (Tall silver bottle with free-on nipples) well this motor kept running and the lines from it got real hot so I pulled the plug also when this started happening (The motor or whatever it is) my truck started to idle really weird so I hooked up the OBDII checker and it said bank 1 lean so I shut it down and unplugged the plug to the little motor thing so it wouldn't drain my battery or catch fire.....

Sorry for the long post just wanted to give you all information that I know of and what happened before and after when the issue started...Con someone please tell me what the heck this thing is?? I've added a picture of it and where it's at marked in red it's that whole pump assembly thing that kept running and got super hot. I will get better pics tomorrow. Thanks for any info you may have or a solution to this problem. :help:

 

[Tex99Tahoe]

Hey wallace. I'm clueless about this model, but could that be part of the emmissions/evaporative control system?

 

[wallace]

Hey wallace. I'm clueless about this model, but could that be part of the emmissions/evaporative control system?

Hi there Tex Thanks for replying, I'm not sure as to what it is I'm pretty clueless myself with what it even does. When it was running constantly it sounded quite like a pump and was just high pitched then once I unplugged it it winded down like a fan. Will post pictures soon as I'm headed outside to work on my avalanche also (Spark plugs nothing major) So you can get a better look at how it's mapped and where the lines run to...But as soon as this thing went haywire and kept running that's when my first ever check engine light came on and said bank 1 too lean, So I'm not sure if this thing is contributing to it.

In all my years of working on vehicles I've never seen one of these things equipped on a car.

 

[wallace]

Pictures.....The pump in the back with the picture taken from the top of it is what keeps running after shutting the engine off...What is it? lol

 

[Tex99Tahoe]

Looks like some sort of enclosed/sealed squirrel-cage or turbine fan. Keep thinking something to do with emissions. I've heard some ramblings of underhood vapor regulations. Maybe find a hint on the emissions plumbing sticker. Can you find any kind of vapor cannister elsewhere? If yes, then this may not be involved with fuel vapor emissions.

On older vehicles, there is a vapor cannister purge cycle that occurs at a specific time, certain engine running conditions have to be met before it'll purge. Acts up sometimes, and causes strange engine symptoms and diag errors.

 

[rockenthebowtie]

Thats your air injection pump you see the little gray relay thats next to it might want to start there chances are the relay contacts shorted iut causing them to stick and complete the power circuit even with the engine off

 

[samotahoe]

yes sir ^ that's correct and is a common problem. I see that a lot at our shop. we at least the tahoes that have air injection. If the air pump is stuck on it will be feeding air to the exhaust upstream and the o2 sensor will see this and trigger the check engine light cuz its trying to add fuel to the system but it doesn't see the fuel. so you get a lean code. be careful you can get a lot of carbon build up in the cylinders if you don't take care of this soon.