high "idle" RPMs

[Great White Versa]

So, today as I as driving home from thanksgiving I noticed something odd with my engine and am wondering it its normal. While going down a long hill I pushed down my clutch and let my foot off the gas. The engine would then drop to just below 1k RPMs and then rise again to about 1.5k. After a few tries, I found that this would only happen when i left the gear engaged (though the clutch was all the way to the floor).

When I got off the highway I found that at lower speeds the RPMs would jump back up, though not nearly as much as at highway speeds.

Can anyone think of why this might happen? Might there be something wrong with my clutch/flywheel that is inhibiting them from completely separating? Should I be worried?

[Ever Victorious]

No, mine does this too. If you put your foot on the brake enough to start decelerating noticeably, the RPM's will go down. the ECU seems to keep the RPMs up a bit when cruising in neutral or with the clutch in so that if you DO drop into gear, it's closer to RPM matched. It drops the RPMs again when you are braking because it assumes you are coming to a stop.

It tripped me up the first couple times I saw it do that, but I can understand why they did it.

[Great White Versa]

Thanks, that's good to know. I was worried that my clutch wasn't getting a full separation from the fly wheel.

As a side note. This morning (even with the clutch to the floor) i was grinding the gears going back into first (there are a lot of speed bumps in my neighborhood - the little ones, not the nice big gradual ones) at less than 5 mph. Any comments on why that might be happening?

[CARI0CA]

#1 :Why are you pushing the clutch pedal (disengaging the clutch in other words) when descending a hill (also called "riding the clutch")? You are are not really saving any fuel doing so. As many new cars nowadays shut off fuel to the injectors during deceleration, reducing fuel consumption/emmisions.#2:You really should let the engine do the braking, shifting to 5th or 4th, etc & "blipping the throttle" before engaging ther gear to match engine speed to road speed as you down shift (also saving clutch & syncro wear). #3:If you do what you are doing on a driving test (especially with a transport truck) you would fail the road test as an "uncotrolled vehicle" by having the transmission disengaged from the engine longer than the time it takes to up- or downshift.

I hope this helps.

[CARI0CA]

It could be the flywheel being very light AND:If you are down shifting, remember to match engine speed to road speed (helping the transmission syncronizers & clutch) by "blipping the throttle." In your instance you could be shifting to quickly from a higher gear to a low gear (say 3rd to 1st) without letting the transmission to "catch up."

Try it, you shifting will be smoother. When cars of yore had high compression motors with light flywheels, sometimes you would have to blip the throttle to UPSHIFT smoothly (because the revs would drop so quickly) & the same in downshifting.

[Ever Victorious]

It could be the flywheel being very light AND:

We've already determined that the flywheel in the Versa is uhm... quite heavy for its size.

[Great White Versa]

#1 :Why are you pushing the clutch pedal (disengaging the clutch in other words) when descending a hill (also called "riding the clutch")? You are are not really saving any fuel doing so. As many new cars nowadays shut off fuel to the injectors during deceleration, reducing fuel consumption/emmisions.

I don't have cruise control. So, after several hours of driving it is nice to be able to disengage the gears and move my feet around while coasting down the hill. Even without the use of the engine break the car usually will gradually slow down (the V is a light, fairly tall car) and if i leave the clutch engaged it will slow the car very quickly.

As a side note, Carioca, do you have some connection to Rio? and if so, what?

[CARI0CA]

I know what you mean in regard to no cruise control. My work '95 E350 deisel van has none either & I drive very long distances in western Canada & do that all the time. I think I may have went into another direction then what you were talking about in your thread.

My wife was born & raised in Rio, actually a real "Girl from Ipanema" like the song. Thus the personalised plate I bought her for the car.

[Great White Versa]

My wife was born & raised in Rio, actually a real "Girl from Ipanema" like the song. Thus the personalised plate I bought her for the car.

Mad props to you, bro. Is she actually from Ipanema or from another Rio bairro? I was in São Paulo a year and a half ago (during all of that police vs. the PCC madness) and had a trip planned for Rio, but had to leave before i was able to go. So I guess I'll just have to go back again