Bilster

iTrader: (21)

I have had my crate 5.3 running for about a year now. I set up my e-fans to turn on at 180 degrees and I have an SLP 160 degree thermostat. For most of the year, the e-fans rarely turned on. There is enough frontal air flow in my truck to keep the fans from turning on. The exception being stop and go traffic in temperatures above 90 degrees. Now it's fall and the fans are going on even at freeway speeds in temps in the high 50s and low 80s....when they never came on at those speeds. My water pump is a relatively low mileage used unit with about 40K on it now. My thermostat has about 4000 miles on it. My aftermarket e-fan set up including sensors from Be Cool have the same 4000 miles. I don't have a temp gauge yet but I know engine temp is rising because the heater works immediately when it used to take awhile to blow hot air. There is no coolant loss. Would the water pump be my first suspected part failing? No squealing or weeping.

fleetmgr

Have you tested the rad cap? If it checks out, I'd suspect the thermostat.