ColdCase

I see a lot of discussions about fan clutches failing to lock, but did not find any for a fan always locked. I saw the shop manual troubleshoot/remove/replace procedure posted. Anyway before I get under the hood and start checking things out I thought I'd check here, may save me some time.

Its been 30-40 degrees and I pulled out of the lot yesterday evening, everything normal. Stopped at a light for maybe 30 seconds and when I started off the fan clutch was engaged and remained so. Talk about howl at 60 mph.... no codes are set. Previously the fan would rarely engage, never when moving more than say 40 mph. 50k miles on the 06. The fan is not frozen to the shaft, as it will turn with engine off, but turns with high resistance.

I'd hate to have to spend $500 to replace the fan clutch with the holidays coming up.

BigIron70

If the fan assembly does not free-wheel and a metallic grinding sound exists, replace the electronically controlled fan drive It is normal for fan noise to be louder (roaring) when Cool silicone fluid within the fan drive unit is being redistributed back to its normal disengaged (warm) position. This can occur during the first 15 seconds to one minute after engine start-up on a cold engine.

zuki_dan

Another thing to remember is when you use defrost the truck automatically turns on the A/C to dry the air and when you pull away from a light the fan will be locked until about 35mph.

ColdCase

Thanks for the suggestions. I've had this truck for about 3 years and am familiar with normal fan clutch operation. This is not normal.

Unless there is something else under the hood that makes the same kind of howl, the fan is locked to at least 2200 RPM and 70 mph.

There is no metallic grinding but it is relatively difficult to spin manually. I don't know if thats normal for these when engine is off and warm or cold.

It acts like the engage solenoid is stuck on lock.