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Cz

Cz 8/1/2011

2000 Honda Civic EX 4 Cyl 1.60L

Engine

When the ac is turned on the car vibrates hard, mostly when stopped at a light

3 Answers


Bill

Bill 8/1/2011

Need to know Idle RPM's when at light with A/C on. And RPM'S when stopped at light with A/C off

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Bill

Cz 8/9/2011

AC on: 1000 rpm
AC off: 1200 rpm

jonnysheparino

jonnysheparino 8/11/2011

If it is a rough idle, you have an engine situation. If it is a strong vibration, check your engine mounts. They are suppose to dampen the engine's movement. I had this problem when stopped for parked, but it would go away when I drove faster. I replaced my side engine and front mount and it stopped. Easy DIY fix for about 100 bucks for the pair of mounts...worth a shot.

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Bill

Bill 8/11/2011

Idle should be constant at around 750RPM, Clean air idle control valve and adjust needle valve. Also, idle may be affected by the cooling system temp sensor. Cold idle could be 1000 RPM but after engine starts to get up to temp the idle customarily starts coming down. Also your cooling system thermostat could be stuck in the open position causing engine to take a lot longer to warm up to tell temp sensor which in turn tells ECM to send a signal to adjust idle down.

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Bill

Cz 8/12/2011

Mt mistake. The initial readings were on a cold engine. I ran it and the tach read about 750 rpm with AC on and off. Sometimes it dipped to around 500 rpm, then would rebound to 750.

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