jcolegrove

hello all,

while doing my p/s pump change, i replaced the thermostat b/c i thought the temp was a bit low... sure enough, the temp gauge is now higher a bit and on the 2nd bar up and i consistently get 2 mpg better in all driving (from 18-20 to 20-23 ). think car was running cold and choking slightly.

anyway, in doing my first real work on the 400, i noticed that the back 'puller' fan runs constantly, even from dead cold? does everyone else's do this? most of my other cars (hondas, mazda, etc) had thermostat controlled fan that came on only when hot...

thanks.
JC

Rice

Are you talking about LS400?
It does not have an electric puller fan. The two electric fans that it does have are Pushers and they only come on when AC is on.

bicol-ini

because this is connected to your serpentine belt, speed is controlled by a fluid clutch, unlike domestics which is controlled by a temp sensor that if a certain temp is reach electric fan wil kicked in , but you can also convert the ls fan to an electric, try lextreme knowledge base,

jcolegrove

thanks bicol-ini, it's a fluid clutch? meaning that it is 'supposed' to run all the time? it just runs at different speeds given the temp?

just seems odd that on start up on a cold day, the fan comes on, at ANY speed, too....

thanks.

JC

GRAND_LS 4

iTrader: (2)

Why didnt these cars have an electric fan?

Very disapointing.

xirforever

The fan is supposed to be on all the time, and does not vary with engine temp, but rather the engine RPM becuase it is connected to your serpentine belt.

EDIT--I think its engine driven rather than by and electrical motor becuase it is quiter this way. And we all know for Lexus the quiter the better; at least thats what they were aiming for.

jcolegrove

thanks,
i'm still not clear then why above it's said it's speed is controlled by a fluid clutch... this implies the clutch goes in/out or controls the speed in some other way. i understand it's run by the serp belt, but if that's the case, what does the clutch do? sorry, getting diff answers and still not clear...

thanks.

xirforever

It has a clutch so it reduces stress on parts when the serpentine belt is quickly reved. For example, start up.