You is low on refrigerant. You hitting 4k rpm is raising the pressure enough to engage it. Got to a reputable AC shop and have them add the proper amount of coolant and oil. Do not do this yourself, as chances are you will mess this up. Our system takes a very little amount of refrigerant.

Oh and the fan not engaging, yea, there is a pressure switch on the refrigerant line, that tells when the fan should turn on. When you are low on freon, pressure switch no work so well, fan doesn't turn on.

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2006 4.8is, Black on White. SOLD Sniff Sniff.

2017 F85 x5m, Black on Red. BEAST MODE


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