2008 Tundra Fan Squeak on Cold Start

Hi There, I have a 5.7 V8 Tundra SR5 and in the last few weeks it has developed a nasty squeak/scream on cold start. Read through some forums and discussions and I have been trying to find if its my Serp or a pulley shot, but have narrowed it down to the fan. Squeak doesn't happen if I start and step on the gas to 2500 RPM for 3-5 seconds. Squeak only occurs for about 10 seconds if I start it without touching accelerator. And doesn't squeak at all if engine is still hot (within 30 minutes of driving). I carefully dropped some WD40 on the fan without touching the serp belt and the squeak went away on that cold start. Only issue is the WD40 evaporates while driving and next start it squeaks again. Anyone have a similar issue or thoughts to fix? Maybe a lithium grease instead of WD40? Or should I replace the fan entirely? Any help or suggestions are appreciated. Thanks in advance!

 

How many miles ya got on that 08?