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Q: Overheating at the traffic light or while AC is on

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My van has been overheating for a long time now. It usually happens when I stop it at the traffic light. Also, it occurs while the AC is working. The AC occasionally blows warm air. I had the thermostat replaced. I changed the fan motor as well. The distributor has been timed and reseated too. I installed the new fan relay. It got blown however, so I put another new one. The oil is changed regularly and looks good. I installed a new water pump along with the steering pump. The belts for the AC and steering pump have been replaced. I don't know what else I could do to stop the overheating. Do you have any suggestion? Thanks.

A: You may have a restriction in your radiator...

You may have a restriction in your radiator or condenser that is preventing the cooling of the respective fluids that go through these parts. Restrictions will cause hot spots and therefore will not allow sufficient cooling of the refrigerant or the engine coolant. These hot spots can be found by using an infrared thermometer to check several spots on the radiator to verify that the temperature is even across the entire surface.

This test would be done with the condenser as well. If a hot spot is found, the part that it is found on will likely need to be replaced in order to resolve the issue, as small passages inside radiators and condensers are very difficult to flush out. Ensure that the replacement of the radiator or condenser is performed by a qualified professional as severe damage to your vehicle may result if these parts are not installed properly. If you want to have the faulty component verified, a technician from YourMechanic can come to your car’s location to diagnose your overheating issue and determine any repairs needed.

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