[Shop-talk] '02 Suburban engine cooling

[Randall]

> The fan's working fine, as best I can tell.

So, it has a thermal clutch and you can tell that the thermal clutch locks
up when it gets hot?

I'm pretty sure a Suburban should have a thermal clutch and a very
aggressive mechanical fan.  If someone has removed the clutch (they do have
a limited lifetime) and installed a standard car fan instead, the fan might
appear to work fine and still not move enough air at idle.

As someone already noted, the mechanical fan on my Buick wagon (with the
towing package) not only makes a racket when the clutch locks up, but also
sucks a noticeable amount of power.  Fortunately, it practically never locks
up.

If you do need more cooling at idle, I would suggest adding an auxiliary
electric fan, rather than replacing the stock mechanical fan.  Electric
fans, while neat, don't move as much air as the heavy duty mechanical setup
with the clutch does.  FWIW, the Buick came stock with an auxiliary electric
fan.

PS, in case it's not obvious from the above, it sounds as though your
problem is lack of air flow.  The biggest, baddest radiator in the world
won't help without enough air flow.

-- Randall