sewebster Posted January 5, 2011 Share Posted January 5, 2011 My fan seems to spin pretty fast all the time, even when the engine is cold. With the truck off I can rotate the fan fairly easily by hand, so clearly it isn't totally seized... I'm not used to non-electric fans. Maybe this is normal. The truck also seems to take a little while to heat up... and the thermostat is pretty new, so I'm wondering if the fan is the problem... Link to comment Share on other sites More sharing options...
krmiller07 Posted January 5, 2011 Share Posted January 5, 2011 My fan seems to spin pretty fast all the time, even when the engine is cold. With the truck off I can rotate the fan fairly easily by hand, so clearly it isn't totally seized... I'm not used to non-electric fans. Maybe this is normal. The truck also seems to take a little while to heat up... and the thermostat is pretty new, so I'm wondering if the fan is the problem... Stick your fingers in the fan while the truck is running, if the fan stops spinning, then the clutch is OK! BTW, I'd wear heavy gloves when performing this test ! lol. Link to comment Share on other sites More sharing options...
ahardb0dy Posted January 5, 2011 Share Posted January 5, 2011 A few ways to tell if the fan clutch is bad are, fan spins at the same speed no matter if engine is at idle or you are revving it fan can easily be stopped while turning with a piece of cardboard (don't try this with your hand please!!) fan has side to side play in it visible evidence of fluid leaking out of the fan clutch I thought the one in my 94 was good until I replaced it, you can not mistake the difference in how it sounds when you rev the engine!! On my 94 the engine temp never went more than 1/4" above the cold mark, the heat was ok but not blistering as other members on here said theirs was, I just replaced my thermostat and flushed the heater core out and now the temp gauge goes just below the half way mark, the heat IS HOT !! 150 degrees out of the vents. My turck takes about 2 miles before it gets to operating temp. I would open open your hood,start the engine, see how the fan is spinning, how it sounds, should be fairly quiet, than raise the rpms quick moving the linkage on the throttle body, the fan should make more noise, and spin faster if it doesn't the clutch is probably bad. I would also suggest checking the metal pipe that connects the lower hose and the water outlet, mine was really bad and had a lot of build up inside of it, not to mention the pinholes in it, just got one from the junkyard, I actually pulled 2 to see which was better, the one I didn't buy looked like the cooling system had never ever been serviced, really bad buildup inside, can imagine what the inside of the engine looked like. Link to comment Share on other sites More sharing options...
Precise1 Posted January 5, 2011 Share Posted January 5, 2011 Please don't stick your fingers in the fan!! This is my simplistic checking method. Spin the fan quickly by hand with the engine cold and off. It should spin 1/4-1/2 turn, not bind or free wheel. When you first start it cold, you should hear fan roar which fades within 1 minute or so as the fan clutch warms up. Your temperature does not significantly increase when you come to a stop after driving 25+mph. Your truck actually warms up. If it passes these criteria, your fan clutch still works as it should. fan has side to side play in itvisible evidence of fluid leaking out of the fan clutch If either of these exist, it probably wont last too much longer. B Link to comment Share on other sites More sharing options...
nunya Posted January 5, 2011 Share Posted January 5, 2011 Stick your fingers in the fan while the truck is running, if the fan stops spinning, then the clutch is OK! BTW, I'd wear heavy gloves when performing this test ! lol. Won't take Nostrodamus to tell you that ain't a bright idea! Plastic blade fan or not! Use B's method...fairly failproof besides obvious visual signs Link to comment Share on other sites More sharing options...
adamzan Posted January 5, 2011 Share Posted January 5, 2011 Also check it for lateral play. Mine was so bad it was making squeaking noises. Link to comment Share on other sites More sharing options...
sewebster Posted January 5, 2011 Author Share Posted January 5, 2011 Ok, I will check this stuff out. Thanks guys. I haven't seen any fluid or noticed any play, but I think it does make a bit of a squeaking sound at idle... Link to comment Share on other sites More sharing options...
adamzan Posted January 5, 2011 Share Posted January 5, 2011 What mine did was as soon as the clutch stopped sounding like a bus on a cold start it would start to squeak. Link to comment Share on other sites More sharing options...
krmiller07 Posted January 5, 2011 Share Posted January 5, 2011 I'm glad someone caught that as a JOKE! How many times as kid's didn't we ignore mom's advise, and despite her telling us NOT to stick your fingers in the the FAN...we did anyways ! Link to comment Share on other sites More sharing options...
ahardb0dy Posted January 6, 2011 Share Posted January 6, 2011 that was funny but incorrect, if you could stop the fan with your fingers, DO NOT TRY THIS !!, it would mean the fan clutch is no good Link to comment Share on other sites More sharing options...
XSrcing Posted January 6, 2011 Share Posted January 6, 2011 (edited) The fan clutch should almost freewheel when the engine is cold. When the engine gets warm it starts to lock up. Edit: when the air passing through the radiator starts to warm up, it starts locking up. Edited January 6, 2011 by XSrcing Link to comment Share on other sites More sharing options...
sewebster Posted January 6, 2011 Author Share Posted January 6, 2011 The fan clutch should almost freewheel when the engine is cold. When the engine gets warm it starts to lock up. Edit: when the air passing through the radiator starts to warm up, it starts locking up. Isn't that the opposite of what Precise1 wrote above? Link to comment Share on other sites More sharing options...
XSrcing Posted January 6, 2011 Share Posted January 6, 2011 (edited) Unless it's freezing outside, a cold fan should spin effortlessly. Think about it, you don't want your fan pulling air through the radiator when the engine is cold, and hardly moving when air needs to be cooling the radiator. But, since they use a viscous coupling, there will always bee some drag regardless of clutch temperature. Edited January 6, 2011 by XSrcing Link to comment Share on other sites More sharing options...
krmiller07 Posted January 6, 2011 Share Posted January 6, 2011 Unless it's freezing outside, a cold fan should spin effortlessly. Think about it, you don't want your fan pulling air through the radiator when the engine is cold, and hardly moving when air needs to be cooling the radiator. But, since they use a viscous coupling, there will always bee some drag regardless of clutch temperature. Every vehicle I've owned with this type of fan, always has had some drag on it. Even when it's -20 below zero outside...like it is now! On the other hand, when it's well into the 80's, as soon as I start the truck it will 'free wheel'until the oil inside or what ever is in there expands, and eventually it will engage the fan or disengage it. Link to comment Share on other sites More sharing options...
adamzan Posted January 6, 2011 Share Posted January 6, 2011 The only time I ever really noticed mine come on was in the summer with the a/c on. With the a/c off it was quiet. Link to comment Share on other sites More sharing options...
sewebster Posted January 7, 2011 Author Share Posted January 7, 2011 Test results: Current outside temp is around 40F. With truck cold I can spin the fan about 3/8 of a turn before it stops. Seems smooth. No noticeable play. When I start the truck the fan spins very quickly, tons of air moving. Revving it causes it to spin faster. Cannot be stopped by cardboard (not even close!). Drove the truck around on the side streets until it warmed up. This took about 3 miles/10 minutes. The gauge was at about 1/4. The heat was pretty hot. Now with the truck running the fan is spinning slower, but the engine is idling lower now too, so I would guess that is major difference. Still can't be stopped by cardboard. Revving increases fan speed. Stopped the truck and spinned fan by hand while everything was still warm. Spins not as far now, more resistance, I guess because it is warmer. So does this all make sense? I guess it's working? I think the only thing that I find odd is the fact that it spins so fast when cold... but maybe it's really spinning a lot slower than the engine. Of course an e-fan would have been off basically the entire time I drove around... Link to comment Share on other sites More sharing options...
XSrcing Posted January 7, 2011 Share Posted January 7, 2011 Your fan is working fine. When the fan clutch goes bad it will usually stop engaging and your engine will over heat in hot weather. Link to comment Share on other sites More sharing options...
Precise1 Posted January 7, 2011 Share Posted January 7, 2011 and/or slower speeds/stopped. So does this all make sense? I guess it's working? Sounds like everything is working properly. B Link to comment Share on other sites More sharing options...
sewebster Posted January 7, 2011 Author Share Posted January 7, 2011 Thanks guys! Link to comment Share on other sites More sharing options...
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