Loud Roar, Howl or Whooooooooooo Noise Problems - Fan Clutch, Blower Motor or What???
My 2006 Ford Explorer makes a loud Howl, Roar or as I call it a Whooooo sound when I have the AC on and am sitting at an idle, and then go to accelerate. I have replaced my Fan Clutch, Water Pump, and Radiator. My Blower Motor has been giving me no problems, it blows cold and hot on all settings, and makes no sound that I know of unless this is it? But I am still getting this obnoxious sound. I can turn off AC while sitting at a light, then accelerate and it doesn't seem to do it, but sorta of still hear THAT sound. Seems to do it more when its really hot outside, which is pretty much all the time since I live in FL. Noticed its really affecting my gas mileage as well. Please, any help would be appreciated. Thanks!
Doubt it has anything to do with heater/AC blower motor, even if that went bad it wouldn't have any affect on gas mileage. You should get the AC compressor checked out though, the compressor or the clutch may be going bad, and if so it can hang up the serpentine belt (causing the racket AND harming the gas mileage). Do it ASAP too, because it may cause the serpentine belt to break.
Wanted to add that you should also have the cooling fans checked out as well, as one or both should turn on whenever the AC is on. (Some cars have one dedicated fan for the AC). A bad bearing might be making that noise. i don't really see that affecting MPG either though, unless you got some overheating going on as well, or multiple problems.
I have 2017 Explorer. It still on factory warranty. I had the same problem with AC compressor last summer. It was noisy if AC is on. And it's affecting fuel mileage!!! Annoying sound! New AC compressor resolved the problem. Now I've got the same problem! Will need to change it again!
2006 Explorer with same issue. Have replaced AC compressor, alternator, serpentine belt, fan clutch and water pump. Still getting the roar when accelerating with AC on. New mechanic says it may be because the fan clutch was not a motor craft part. Any thoughts on that?
REF MY 2009 4.0 FORD EXPLORER. Your fan has an electric clutch. Under normal conditions, the fan clutch slips, by design, and the fan turns quite a bit slower than engine rpm. This is to prevent it from turning at engine rpm (especially under acceleration/high rpm) and because your fan does not need to turn that fast EVER to keep the engine cool! The computer will TELL the fan clutch to lock up ONLY WHEN it thinks the engine is running HOT! When that occurs, the clutch engages and your fan now turns at engine rpm and much faster than normal. The noise you hear is the rush of air now being pushed by the faster turning fan! YES, it takes a lot of energy to pull that fan at that speed and YES, your gas mileage will be poor as a result if this occurs all the time! This is the main reason why the entire auto industry starting using clutched or electric fans vs the old school lock up fans! To trouble shoot, simply unplug the electrical connector to your fan clutch and drive it. If the Whoosh is gone, you have proven it is the fan speed increase related to the cutch locking up!! Now you need to find out why? REMEMBER!: this is supposed to happen WHEN YOUR ENGINE RUNS HOT! Step 1: Ensure you engine is not running close to HOT! Do not assume all your gages and warning lights are telling you the truth! I do not know what sensor or combination of sensors send the information to the computer to tell the clutch to lock up! Water temp sensor? OAT sensor? Transmission temp sensor? Coolant level sensor? Other sensors/devices? Thermostat? Radiator? Thermostat housing? My 2009 made the noise mostly in the summer and with the engine NOT EVEN WARMED UP. I had trouble keeping my coolant level FULL and could find no evidence of leaks! THE FIX FOR ME: I found my plastic thermostat housing was cracked at the factory glued seam in the lower half of the housing. The coolant would slowly leak out and into the 'valley' on top of the V6 block and between the heads. That area can hold a lot of water BEFORE it overflows. As a result, it would evaporate and NEVER spill over and onto the ground below! NO SIGN OF A LEAK, except when you use a strong flashlight and look UNDER intake into the valley on top of the block between the heads! I changed the thermostat, the water temp sensor and the lower half of the thermostat housing and BINGO...the Whoosh was instantly gone! Good Luck!
That's why my top engine block is all rusty looking
YEP...see all those whitish specs on the hoses and parts behind your plastic thermostat housing? That is coolant leaking out of your cracked housing. The housing is two piece. The bottom half is pn 8592A Water Outlet Connector ($57 @ Ford dealer). My lower half was cracked. There is a rubber seal/gasket under it (pn 8255 $7 @ Ford dealer). NOTE: my 4.0 V6 is stubborn on getting coolant level back to full. It took several top off FULL when HOT over a 2 days before it remained FULL when HOT and FULL when COLD. the whooo sound goes away when you get it FULL!
