Rev's hunting at idle

ac427 · 23-09-2019, 01:12 PM

The rev fluctuate at idle like someone is gently pressing the throttle.

Does this sound like a vanos solenoid issue?

I'll check for codes but i don't think there are any.

ac427 · 31-10-2019, 09:13 PM

I replaced the Vanos solenoid and gasket but the hunting issue still remains.

Has anyone experienced this?

Bounce · 31-10-2019, 11:40 PM

Turn the air con off and see if it still happens

M3 KVU · 01-11-2019, 09:09 PM

Had these symptoms earlier this year and it was the front TPS.

sailorbaz · 05-11-2019, 09:19 AM

Quote:

Originally Posted by Bounce

Turn the air con off and see if it still happens

Yip, mine has always done it with the AC on. Just the load I suppose.

ac427 · 10-11-2019, 05:11 PM

Quote:

Originally Posted by M3 KVU

Had these symptoms earlier this year and it was the front TPS.

Did an error for the TPS sensor show up in diagnostics?

M3 KVU · 11-11-2019, 09:58 PM

Quote:

Originally Posted by ac427

Did an error for the TPS sensor show up in diagnostics?

Yeah it did , iirc it was inlet cam sensor bank 1

**cantfind1** · 12-01-2020, 07:29 AM

You get this sorted?
Have you done a vanos pressure check? Should be up around 1500-1600psi

ac427 · 13-01-2020, 02:16 PM

Quote:

Originally Posted by cantfind1

You get this sorted?
Have you done a vanos pressure check? Should be up around 1500-1600psi

Not yet although it is intermittent.

How would you measure the vanos pressure?

I did get an error code "Inlet VANOS, advance valve" via PA Soft. So i thought i might replace the TPS but knowing my luck if it is the TPS it will the one below the airbox.

**cantfind1** · 14-01-2020, 07:19 AM

https://youtu.be/YqYD03Ec8js

I'd also run vanos test with Diagnostics. Hunting at idle generally caused by a vanos issue.
Seeing that you have a code as well seems a great place to start.

Vanos pressure very important. Low pressure cams will not move or be lazy.

Will also cause issues with shifting with SMG as both ECUs are not seeing what they expect.

23-09-2019, 01:12 PM	#1
ac427 S2 - Picking it up Join Date: Feb 2011 Posts: 71 Casino cash: $977	Rev's hunting at idle The rev fluctuate at idle like someone is gently pressing the throttle. Does this sound like a vanos solenoid issue? I'll check for codes but i don't think there are any.

31-10-2019, 09:13 PM	#2
ac427 S2 - Picking it up Join Date: Feb 2011 Posts: 71 Casino cash: $977	I replaced the Vanos solenoid and gasket but the hunting issue still remains. Has anyone experienced this?

31-10-2019, 11:40 PM	#3
Bounce CSL Register Uber-poster! Join Date: Nov 2009 Location: Cornwall Posts: 7,057 Casino cash: $35793	Turn the air con off and see if it still happens

01-11-2019, 09:09 PM	#4
M3 KVU S2 - Picking it up Join Date: May 2015 Posts: 59 Casino cash: $4159	Had these symptoms earlier this year and it was the front TPS.

12-01-2020, 07:29 AM	#8
cantfind1 S5, Sport Off, DSC M-track Join Date: Oct 2009 Location: Sydney Australia Posts: 675 Casino cash: $6490	You get this sorted? Have you done a vanos pressure check? Should be up around 1500-1600psi

14-01-2020, 07:19 AM	#10
cantfind1 S5, Sport Off, DSC M-track Join Date: Oct 2009 Location: Sydney Australia Posts: 675 Casino cash: $6490	https://youtu.be/YqYD03Ec8js I'd also run vanos test with Diagnostics. Hunting at idle generally caused by a vanos issue. Seeing that you have a code as well seems a great place to start. Vanos pressure very important. Low pressure cams will not move or be lazy. Will also cause issues with shifting with SMG as both ECUs are not seeing what they expect.