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harmonic shudder/vibration at idol

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Old 11-12-10, 08:44 AM
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atoyot
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Default harmonic shudder/vibration at idol

any idea where to start looking for the cause of this?

Basically it's just started about 2-3 months ago. When i start the car i get a vibration almost like a shudder around 1,000 rpm when the car idols. Give it gas and it goes away. It's not bad, but it never happened before. It's not a constant vibration, it oscillates every couple of seconds.

The best way i can describe it is if one of the pulley's is slightly loose and has a little vibration as it spins. That's probably the first place i will check. Second place i will check is a belt to see if it's cracked or if there is a problem.

Thought i would ask if anyone has experienced this before?
Old 11-12-10, 10:56 AM
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williamb82
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sounds like a slight miss. id check the plugs, and also run a can of seafoam in the gastank to make sure the injectors are clean. any engine codes?
Old 11-12-10, 11:54 AM
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GillaG
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Check your trans mount also. Mine was idling smooth until I got up to 1000 RPM and above and then the quick vibration came through the car. I replaced the mount and it was split in half, now the vibration is gone. Just have a vibration in gear at idle even after I neutralized the transmount but I think it is because of a faulty TP sensor or air bypass valve.
Old 11-14-10, 06:03 AM
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atoyot
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thanks for the replies.

No engine codes.

I will check the plug wires to make sure they are secure.

A little more information, it's not a really bad shudder, it's just enough for me to feel through the seat and steering wheel. Doesn't make any strange noises.
Old 11-20-10, 01:35 AM
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skperformance
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sounds like the clutch for the fan is locked up . If its making alot more noise like a turbine when revved when the car is still cold , that's the problem.
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