1993 GMC Sonoma Owner's Manual - Page 231

KO721 8. Thenreplacethepressurecap.Besu-rethearrowsonthepressurecap lineuplikethis. Engine Fan Noise Thisvehicle has aclutchedenginecoolingfan.Whentheclutch is engaged, thefanspinsfaster to providemoreair to cool theengine. In mosteveryday drivingconditionstheclutchisnotengaged.Thisimprovesfueleconomyand reducesfannoise,Underheavyvehicleloading,trailertowingand/orhigh outsidetemperatures,thefanspeedincreaseswhentheclutchengages. So youmayhearanincrease in fannoise.Thisisnormalandshouldnot be mistakenasthetransmissionslippingormakingextrashifts. It ismerelythe coolingsystemfunctioningproperly. The fanwillslowdownwhenadditional cooling is notrequiredandtheclutchdisengages. You mayalsohearthisfan as thefanclutchdisengages. noise whenyoustarttheengine.Itwillgoaway If a Tire Goes Flat It'sunusualforatire to "blowout"whileyou'redriving,especially if you maintainyourtiresproperly. If airgoesoutofatire,it'smuchmorelikely leakoutslowly. But if youshouldeverhavea"blowout,"hereareafewtips aboutwhat to expect and what to do: If afronttirefails,the flat tirewillcreateadragthatpullsthevehicletoward thatside. Take yourfoot off theacceleratorpedal and gripthesteeringwheel firmly.Steer to maintainlaneposition, then gentlybraketoastopwelloutof thetrafficlane. to 5-1 5