Quote:
Originally Posted by philmcneal
if you engine kill a lot then you don't have to worry about engine over heating right?
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i have noticed that doing more engine-off coasting has resulted in my cooling fan coming on more frequently. but i think this has less to do with the grille block, and more to do with shutting off the engine after a high-load event:
if i go a couple of blocks between 2 stops, i'll accelerate approximately halfway, then kill the engine and coast to the next stop. in other words, the engine is killed just after a relatively high load (and i mean relatively - accelerating at a gentle pace), when it's generating more heat.
that heat isn't immediately dissipated because the water pump stops pumping when the engine stops (unlike the prius, which has an electric pump, and which may continue pumping after the motor is shut off).
what this means is FAS *may* subject a normal motor to higher temperature peaks and hot soaks than normal driving. also, since the stationary coolant in the radiator cools more rapidly with the engine off while coasting, the engine is subjected to wider coolant temperature fluctuations when restarted than an engine driven constantly.
it reminds me of a bit of advice a knowledgeable old timer gave me once, which is you shouldn't shut an engine off immediately after exiting the highway (high load) because the cooling system won't have had the chance to dissipate the built up heat.
whether it stresses engine components (head, head gasket?) to the point of affecting longevity, i can't answer.
something to think about.