RPM drop when releasing accelerator pedal

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NewNeptune
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RPM drop when releasing accelerator pedal

Post by NewNeptune »

This problem seems to be solved for me. The problem was that at city speeds, if I let off the gas, it would drop off to about 1000 RPMs and then surge back to 1400 or so. Now it doesn't seem to do that and simply drops to 1400, thus avoiding the usual lurch. I had posted about this before and other members reported feeling it, but saying there was nothing to be done.To solve it, I took my car in because of a suspension noise when going over speed bumps. It sounded like a crunch to me but the dealer described it as a tennis ball sound. After two days (they barely had it ready the second day) they came back with the problem being a a motor mount that wasn't set properly.So, my problem with the suspension seems to be gone as well as the drop out. My idle seems to be back to what it was when I bought the car (it was starting to get a bit rough).Just thought I'd share.
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BlueCrush
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Re: RPM drop when releasing accelerator pedal (NewNeptune)

Post by BlueCrush »

Good to hear for future reference. I might have the dealership check my motor mounts next time I am in for an oil change.
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joatmon
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Re: RPM drop when releasing accelerator pedal (NewNeptune)

Post by joatmon »

when I saw the thread title I thought "isn't that what is supposed to happen?" glad you got the problem fixed.
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NewNeptune
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Post by NewNeptune »

This update was long overdue, but I forgot about it. It really must have been them resetting the ECM (by unplugging the battery I guess) because it's since gone back to the way it used to.
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Petrucci914
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Re: (NewNeptune)

Post by Petrucci914 »

I have this issue too, it's annoying. It's back for you now? I thought motor mounts or some crappy CV Joints.
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NewNeptune
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Post by NewNeptune »

Yep, if I'm below 50 MPH and I let off the gas, RPMs drop way down and then surge back up.
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kevera
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Re: (NewNeptune)

Post by kevera »

Sounds like your IAC valve acting up.Soon it will stall on you.
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Petrucci914
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Re: (kevera)

Post by Petrucci914 »

I dunno, that would only act up at idle, not the other issue he's talking about. Did the guy only replace one motor mount? If he did then it is possible the other one went bad.........usually you replace both. Did he show you the bad motor mount?
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NewNeptune
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Post by NewNeptune »

Oh, the motor mounts were fine, supposedly, just not installed properly. As far as idling, it idles fine. This is a problem that other members have reported. Does it happen to you? Try going up to 40 MPH and then watching the tach after you completely let off the gas.
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Petrucci914
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Re: (NewNeptune)

Post by Petrucci914 »

Ya, I have the same issue except that part doesn't bother me as much. I just don't like it when I go to stop for a red light and it turns green so then I step on it and the car kind of lurches. I looked through some TSBs (the titles) and there was one issue with the tranny solenoids getting dirty and causing weird stuff in 1st and 2nd gear but I had my tranny flushed a while ago. I'm still thinking motor mounts but I have no idea.
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NUBlackshirts
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Re: RPM drop when releasing accelerator pedal (joatmon)

Post by NUBlackshirts »

Quote, originally posted by joatmon »when I saw the thread title I thought "isn't that what is supposed to happen?" glad you got the problem fixed. Ha! That's sort of like "Hitting the brake pedal causes my car to slow down."
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NewNeptune
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Re: (Petrucci914)

Post by NewNeptune »

Quote, originally posted by Petrucci914 »Ya, I have the same issue except that part doesn't bother me as much. I just don't like it when I go to stop for a red light and it turns green so then I step on it and the car kind of lurches. I looked through some TSBs (the titles) and there was one issue with the tranny solenoids getting dirty and causing weird stuff in 1st and 2nd gear but I had my tranny flushed a while ago. I'm still thinking motor mounts but I have no idea.Are you saying that when you stop, it does this or when you come close to a stop (<10 MPH) but not quite stopping? If it does this when you come close to stopping, does it work like this: Slow to 8-10 MPH, slowly apply the gas, RPMs surge up, drop down and then start accelerating like normal? If so, that's normal. I took mine to the dealer for that and they said that there is nothing wrong with it and the technician's Vibe does that as well. I believe I asked about it here and other people said it was normal, so I concluded it was normal.
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Petrucci914
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Re: (NewNeptune)

Post by Petrucci914 »

If I'm at a dead stop and I get on the gas it's just fine. But like you said, it's when you're slowing down to a dead stop and then you give it gas. At point it kind of lurches through the gear, it's not a smooth or comfortable shift at all. Which makes me think motor mounts because when you go to stop the engine will lurch forward and then when you torgue it it'll go abruptly the complete different direction onto the rear motor mount.
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NewNeptune
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Post by NewNeptune »

Yep, that's exactly what I'm talking about and there is nothing wrong with it. I even asked the dealer. They quite literally, "all do that."
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Petrucci914
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Re: (NewNeptune)

Post by Petrucci914 »

That's makes me feel a bit better. I'm going to upgrade my torque mounts and see if that makes it feel a bit better. I was also thinking of looking at my TPS to see if it was dirty and causing some hesitation. Can I pop that out easily and clean it with some MAF cleaner?
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vette
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Post by vette »

Has anyone found the problem to this? I have this exact same problem when I let off the gas the RPM's drop down to 1000 then the car downshifts and revs back up to 2000. It just started happening. It is not normal, I've owned this car off the lot and it never did this before. When I let off the gas the rpms stayed as is and then gradual slowing. The car has 40K miles now. Any help?
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