Good day..

I have always noticed my 03 G35 is loud when I start it up.

The other day I started it with the hood up. The temp outside was about 15F. Cold!

The cooling fan was turning quickly. Why??

Should it turn when it is that cold outside? What is the best test procedure for this type of fan?

thnxs!!!

My Q45 does that too.Paul Wall said it's the fan clutch.

Nope I said that the fan clutch needs replacement if its always going at full speed (ie: When the car is warmed up or its warm outside) It should only be at full speed for a couple of seconds when the vehicle is cold.

Our G has an electric fan and goes through a "self test" type routine regardless of the temperature. I'll hear it switch to high mode, then back down to a lower speed in a few seconds - even when it's very cold.

From reviewing the service manuals, the 2003 and 2004 A/T models could have come from the factory with either a belt driven fan or a single electric fan. At some point there was a revision in 2004 (the FSM says it's for the 2004.5 model year) in which all models came with the same dual electric fan setup.

So if your fan is belt driven, then it's possible that the fan clutch is bad. If it's electric then you'll need to follow the diagnostics to see what's wrong - if anything.

Heath
Modified by Q451990 at 12:01 AM 2/14/2010