Throttle body chatter

[DavesSV6Tonner]

One for the brains trust.
I was checking the VZ Alloytecs fluids on Sunday and I noticed when I had the engine running to check the transmission fluid that the throttle body was making a chattering noise during the fast idle. When the fast idle dropped the chattering stopped however when increasing the revs with the right foot I could hear the chatter come in as the revs rise above idle and then as the revs rise higher the chatter seems to subside.

This chattering noise does not sound normal to me and I am thinking this is going to end in a complete throttle control failure if I don't do something about it soon.
I have searched for info on this issue without much success.

 

[Fu Manchu]

I doubt you are hearing the throttle body. If it were was making that noise, the only part that could create that noise is the butterfly. It has to close to do it, so the revs would be going all over the place in such a circumstance.

Maybe get it off the car and make sure the screws are tight on the butterfly to be sure. Do that off the car. Last thing you want is the risk of a screw dropping inside.

I’d say it’s the purge valve making the sound.

 

[DavesSV6Tonner]

sounds exactly like this.

 

[krusing]

I doubt you are hearing the throttle body. If it were was making that noise, the only part that could create that noise is the butterfly. It has to close to do it, so the revs would be going all over the place in such a circumstance.

Maybe get it off the car and make sure the screws are tight on the butterfly to be sure. Do that off the car. Last thing you want is the risk of a screw dropping inside.

I’d say it’s the purge valve making the sound.

As above ^^^^
I had the Purge valve clicking on my LY7, and it quite loud, and also wondered what it was,
worked out it was coming from the LHS of the intake manifold, [Solenoid that is rubber mounted on the bracket]
I picked one up from the wreckers, fixed the problem.

 

[krusing]

I had a thought, might be off track,
but,
Could the Throttle Resistor [being fly by wire] be resistive that could cause the throttle to chatter ?

I have noticed on my LY7 that when I am using the accelerator, I can feel the car pulsating a very little bit,
But when I have the "Krusing Kontrol" active it doesn't do it.
That why I am thinking , does the accelerator potentiometer/resistor needs cleaning, assuming it can be removed to service it.

 

[DavesSV6Tonner]

I have heard the sound the Purge valve makes. I am sure it's not the purge valve making this noise.
I could feel the chattering in the throttle body.
Driving home from work yesterday arvo I pulled up at a stop sign and the engine gave two distinct coughs like it was going to shut down but the revs picked up again thankfully.

 

[krusing]

I have heard the sound the Purge valve makes. I am sure it's not the purge valve making this noise.
I could feel the chattering in the throttle body.
Driving home from work yesterday arvo I pulled up at a stop sign and the engine gave two distinct coughs like it was going to shut down but the revs picked up again thankfully.

That almost sounds like a corroded/loose terminal/pin/plug.

Any DTC's, Past or Present ?

May be check all the connectors/plugs/pins ?, inc: the ECU plugs.
And give them ALL a blast with Contact Cleaner.

 

[Drawnnite]

You may need some 5 pointed star bits if you do want to pull the T/B apart.

Not sure if the internals are the same as what's on the SS but those were needed and youde rather have them before you start (unless you do have other vehicles etc you can just jump in and drive)

First steps of a quick open, strip and clean would be a good start. Could be something simple.

 

[DavesSV6Tonner]

That almost sounds like a corroded/loose terminal/pin/plug.

Any DTC's, Past or Present ?

May be check all the connectors/plugs/pins ?, inc: the ECU plugs.
And give them ALL a blast with Contact Cleaner.

I haven't put the scan tool on it cause I haven't had a check engine light.
Started the VZ again this afternoon and everything behaved itself, no chatter noise whatsoever.
I will have a look and clean the harness connectors you suggested. Just have to get some contact cleaner.

 

[DavesSV6Tonner]

You may need some 5 pointed star bits if you do want to pull the T/B apart.

Not sure if the internals are the same as what's on the SS but those were needed and youde rather have them before you start (unless you do have other vehicles etc you can just jump in and drive)

First steps of a quick open, strip and clean would be a good start. Could be something simple.

I have a reasonable collection of Torx bits but haven't ever seen 5 point bits.
Other vehicles to use isn't a problem.