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Q: Air con sound knocking

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My car is Nissan ELGRAND, Aircon compressor got knocking sound. Have send for Aircon flushing, change of belt and tighten all bolts. Knocking sound still can be heard but less. Previously knocking sound can be hear when accelerated. Please assist what to do.

If your air conditioning compressor is making a knocking sound the best thing to do would be to have it replaced by a qualified professional. It is very bad on the engine to run the air conditioning when the compressor has faults that cause resistance. I would recommend having a mechanic use a stethoscope on the compressor to diagnose the noise verify that the compressor is actually at fault. Once this has been verified the air conditioning compressor can be replaced and this issue should be resolved.

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