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Q: I have a 1998 Chevy 2500 van with a 5.7-liter gas engine. It has a clench fan that sounds loud at times, and I be excited it is a waste of horsepower. I want to take out it and install an electric one. The clutch fan is easy to turn when the engine is cold, and I guess the seize engages at the time that the hot air hits it.

A: It sounds like your thermostatically controlled fan clutch is operating strictly, since it spins freely when cold and now and then engages completely. Your longitudinally mounted engine uses a mechanical radiator cooling fan, different the charged with electricity fans used in transverse-engine, front-wheel-drive cars. You’re proper that mechanical fans require a lot of energy to draw out them — but that’s wherefore your fan has a clutch. This mechanism allows the fan to largely freewheel under most conditions — saving gas — and commit only when needed to cool.

Are you driving the van in hilly terrain or towing a trailer? If not, other than rare fan clutch engagement may indicate a cooling-system deficiency, such as a restricted or under-capacity radiator.

Converting the fan to an full of fire designation is possible, though the parts cost and effort would likely not be recouped by way of combustible matter savings.

One of independent choices is the Zirgo HFM-ZFU16S (3,600 cubic feet per minute) reversible electric fan ($225 at SummitRacing.com) and a high-quality thermostat/relay wiring small tub such as the Painless Wiring 30103 ($65, also from Summit).

Another option (if short time allows) is to install a smaller, quieter electric fan to supplement your existing involuntary fan. Your thermostatic fan clutch would likely not engage as many times, if ever.

E-mail Brad Bergholdt at under-the-hood@juno.com