Why does it do that when it's cold?
I know it's supposed to go to about 2000 RPM to warm up the precats, but after the initial roar stops, I can rev it up to the same RPM and it is quiet.
My thoughts: the fan comes on high speed on first start for a few seconds
or it's metal on metal from no lube yet.
My 2007 4.0 with 67,000 miles on it does the same thing. I've chalked it up as normal, been like that since I bought it with 52,000 miles. It is the clutch fan on mine, never though it was an issue as it disengages/engages as it should.
It's the fan clutch doing it's job. You will notice it now that the weather has changed to colder fall/winter temps. It will go away when we get the back to warmer spring/summer temps.
IMO it is my favorite thing about the truck! Music to my ears when I start it in the cool mornings. I walk across the street to get the neighbor her paper while it warms up and grin while it roars awake.
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2010 SE 4x4 King Cab - aka the Stormtrooper
'06 Black Powdercoated 4-Spokes
Big Country Step Bars
Dolphin Low Profile Tool Box
Alpine 6.5's / 6x9's / Pioneer 10" Sub
Sony iPod Head Unit
CoverKing seat covers
I hate it!
Sounds like a dragon on start up.
It's embarrassing to me when people are around.
Plus it makes it hard to sneak out of work early when the general manager's office overlooks my parking spot.
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