This just in... Radiator fan.

[ChevMali99]

While doing the EGR thing I described on another post I noticed that the radiator fan is always on at low speed in spite of temperature being no where near half. Coolant levels are fine and the heat in the cabin is fine, so why are the fans coming on and staying on?

[ChevMali99]

Here's what I've noticed so far: I've driven around with the temp needle stuck right on the middle or below and the fan does go off. That leads me to believe is not any relay or fuse issue, I've inspected both and not sign of burn. I've felt the cabin temp get hotter, particularly when I place the vents to blow air exclusively from the floor, and when that happens I pull over to see what's going on with the fan, it's off. I'm inclined to believe the thermostat is bad.

Now here's the thing, I'll be willing to drive around with this condition for a while except that, the EGR is not throwing back a ready reading; thus the car is not ready for inspection... Are the thermostat and EGR functions related? Second, a few weeks ago, a so-called technician from a lube place topped my reservoir with anti freeze. The next day, Thanksgiving Day, while idling at the in-laws the top radiator hose burst, could that be related to the thermostat or was the inconvenient episode related to simply overfilling the reservoir?

[ChevMali99]

Surfed a bunch of YouTube, anything related to radiator, fan, thermostat; found a few interesting heater core cleaning vids along the way. In the process I saw & learned how a thermostat works, leaving me with more questions regarding my situation.

The day the top hose on the radiator burst the engine was hot so, theoretically, the therm should've been opened and not burst; unless the hose was really deteriorated (at 3 years old?).

On the other hand, fast forwarding to now, say the thermostat is faulty and in deed closed, why hasn't the hose burst again? A closed thermostat can explain the constant running of the fan but not why the engine temperature remains in the middle or below; in fact such condition is a sign of an open thermostat.

Either way there seems to be a thermostat problem, will solving it bring the fan back to normal operating conditions? Will it get the EGR to function properly and pass NYS emissions? Stay tuned.