Fan Frazzle

the air should suck in the front and blow out over the engine. when the bonnet is closed all airgaps around the radiator should be shielded with rubber strips. any gaps in the shroud or surrounding shields will allow air to bypass flowing through the core.

 

Is there any obstructions in the A/C condenser, CAC or radiator? Check for debris with a flashlight after it gets dark out. Air should only go towards the engine. If there is blockage, low air pressure or low water pressure, from the fan side towards the grill will remove a lot of it. Pressure washing the radiator could bend some copper cooling fins over.

 

My truck is same way Freightliner I myself think it’s normal. The fan sucks air in. I believe it doesn’t do it running down road. But sitting Not all the air magically flows over engine. It hits engine and back out the only real opening between bumper and hood. If Radiator fins were blocked it would run hot.same if air to air or a/c fins were blocked. I do agree to wash all Finns blow with air be careful with power wash easy to bend fins

 

It should blow back over the engine, sounds like a mystery!