Diagnosis Help: Vibration after reving engine in neutral, once revs back at 1000
03-10-2003, 09:18 AM
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Diagnosis Help: Vibration after reving engine in neutral, once revs back at 1000
Question - Has someone else experienced this and know what it might be?
Sympton - In neutral, after I have reved the engine in neutral to 3000 to 4000 RPM, and after the engine returns to 1000 RPM, and after a brief pause, there is a shudder/vibration.
Additional Facts - The vibration seems to be coming from the front (and thus I don't think it is the imfamous differential shakes). The vibration is worst when the engine is cold in the morning. But will do it after it has reached full temperatures, just not as noticable. After driving 20 minutes on the highway the problem seems to subside completely. MY2001, 16,000 miles, Mobil 1. The oil was changed on Saturday and this did not help. My first thought is that it was the clutch not disengaging properly or the transmission, but since it does it in neutral with the clutch depressed, this did not seem to me to make sense. (I only noticed it originally when parking, revving a little to go back and forth in first and reverse, which reproduced the same symptom after depressing the clutch. But, after further "testing," I realized that the problem persisted even when not in gear at all.)
Any thoughts would be greatly appreciated before I take it to the dealership. Thanks.
Elton
Sympton - In neutral, after I have reved the engine in neutral to 3000 to 4000 RPM, and after the engine returns to 1000 RPM, and after a brief pause, there is a shudder/vibration.
Additional Facts - The vibration seems to be coming from the front (and thus I don't think it is the imfamous differential shakes). The vibration is worst when the engine is cold in the morning. But will do it after it has reached full temperatures, just not as noticable. After driving 20 minutes on the highway the problem seems to subside completely. MY2001, 16,000 miles, Mobil 1. The oil was changed on Saturday and this did not help. My first thought is that it was the clutch not disengaging properly or the transmission, but since it does it in neutral with the clutch depressed, this did not seem to me to make sense. (I only noticed it originally when parking, revving a little to go back and forth in first and reverse, which reproduced the same symptom after depressing the clutch. But, after further "testing," I realized that the problem persisted even when not in gear at all.)
Any thoughts would be greatly appreciated before I take it to the dealership. Thanks.
Elton
03-11-2003, 08:46 AM
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I've had the same problem. I took it back to the dealership a couple of times thinking that the idle speed is set too low. It almost feels like it's going to stall. I feel mine in the engine and the exhaust. The dealer says everything is fine.
I'd be interested to hear any comments. Maybe it's just 2001 Silverstone cars with red interior.
I'd be interested to hear any comments. Maybe it's just 2001 Silverstone cars with red interior.
03-11-2003, 09:11 AM
#3
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Mine does the same from time to time. It is the ECU learning new intake variables or the MAP sensor having issues. Give a rap or 2 on the top of it.
Or it could be Silverstone/Red cars in general. Mine is an '00.
Or it could be Silverstone/Red cars in general. Mine is an '00.
03-11-2003, 10:36 AM
#4
When it goes back down to 1000rpm, does it actually dip below this rpm while it's doing its shuddering? If so, this is a common issue and "Pinky" is most likely correct in his assessment. Give the MAP sensor a whack.
There is a whole thread just posted about the MAP sensor by our resident expert. See here:
https://www.s2ki.com/forums/showthread.php?...threadid=109736
There is a whole thread just posted about the MAP sensor by our resident expert. See here:
https://www.s2ki.com/forums/showthread.php?...threadid=109736
03-11-2003, 10:51 AM
#5
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I love it. GIVE IT A WHACK!
03-11-2003, 01:04 PM
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I'm trying to gauge interest in a possible future product. How much would you pay for a "wack-a-map" switch for the console? Would it be preferable to have the "wack-a-map" actuator powered by the high beam switch? If you had modifry's high-beam garage door opener mod, you could wack the map sensor every time you open/close the garage door! 
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03-11-2003, 01:16 PM
#10
Our idle is controlled by an EACV, right? Wouldn't it stand to reason that the EACV is completely closed when the revs are significantly higher than idle, and the throttle is open? I wouldn't be surprised if there was a "normal" reaction time for the ECU to actuate the EACV after the throttle is released, causing the idle to fall below normal for just a second.