Rpm jump when disengaging clutch at idle

[Tacomonster]

So I was at an intersection waiting for the light to turn green. When I press the clutch pedal in before moving the gear shifter and before gassing it, I notice that my rpm would jump up 300 rpm. I replicated this again thinking that my right foot may have hit the throttle and to my surprised it was repeatable. I was curious if you guys have insight as to why this is. Also l, is this something I should be concern about?

 

[Dog Dad Wagon]

Sounds like clutch position sensor may be off. The ECU has a stall-prevention protocol that senses drag on the drivetrain at idle engine speeds/<5mph wheel speed, and ups the RPMs to 1100 or so, which is about 300 above idle. It likely takes input from the clutch position sensor, which is why I’m thinking an issue with the sensor may trigger the stall prevention if it’s happening upon depressing the clutch rather than letting off.

this is conjecture. I will tip my hat to the rest

 

[Subliminal]

Sounds normal. My car does this too, especially when warming up. Also happens when letting off the clutch

 

[Ridebjj]

I get this on occasion too - a jump of about 200 rpm. Maybe even less.

I haven't bothered to take down details of when it does and does not happen for the purposes of finding the reason. Off the cuff I think when the car is fully up to all temps, it doesn't happen. Or, not as much.

 

[art_mark7]

ditto

 

[Tacomonster]

Sounds like clutch position sensor may be off. The ECU has a stall-prevention protocol that senses drag on the drivetrain at idle engine speeds/<5mph wheel speed, and ups the RPMs to 1100 or so, which is about 300 above idle. It likely takes input from the clutch position sensor, which is why I’m thinking an issue with the sensor may trigger the stall prevention if it’s happening upon depressing the clutch rather than letting off.

this is conjecture. I will tip my hat to the rest

Interesting, maybe this is a Volkswagen thing but why would you need a clutch sensor? Even if the goal is to prevent a stall, what would cause a stall outside of user error?

 

[bobloblawGTI]

Mine does this as well fwiw. Always assumed it was normal which sounds like from this thread it may be.

 

[Strange Mud]

+1. Hombre's mention of cold is spot on. I've heard it described as clutch nibble. From description it's normal

 

[hans611]

Mine does this too....

 

[Tacomonster]

+1. Hombre's mention of cold is spot on. I've heard it described as clutch nibble. From description it's normal

Yeah it was 22 F outside when I was driving it. Y’all really helpful folks. Thank you for clarifying the concern.