I have a 1998 F150 V8 4.6. The fan clutch always stays on and the truck is very loud. When the rpm's go up (around 4000) the fan gets even louder and starts to whine. We replaced it with a new one and it still stays on. Maybe we did it incorrectly? We average about 12 miles to the gallon around town and 7 when towing our trailer that is about 3600#'s. Maybe the mileage would be better if the fan wasn't always running? Any help would be great.

Dawn

 

Did you replace the original with an aftermarket clutch or OEM?
Mine went at about 110K and I replaced with an Imperial from Autozone and wish I had not cheaped out. I have replaced it 3 times since(133K now) and am ready to do it again. All for the same reason, they are engaged more than original. More noticeable in summer heat but my truck feels like a dog off the line until the thing finally eases up (8-12 secs.).
I would love to get the electric fan kit but they are pricey. I think I'll search the junkyards for OEM before I put another Imperial in and eat the $54 it costed.
If you mean it is engaged full boar full time I would replace again unless there is any possibility the fan blade could have been re-installed backwards.
Good Luck!

 

Went to the dealer today. Had fan clutch replaced for $221.00, seems to be running like a champ.

Thanks for the input.

 

For future reference. I too had problems with the aftermarket clutches. I bought a low mileage used one from the junkyard for $35.00 and it works great.

 

I'll second that vote, that the aftermarket units stay engaged way to much. It's annoying to have the jet engine type airflow when the motor starts cold from sitting overnight. Wonder what makes them operate so differently? I know the Imperial is smaller than my OE unit. Should've went OE or better yet electric, but you all know how $$$ problems go. It just sucks to go back to OE when you work in a parts store and get a discount.
Since my WP and fan clucth change I have developed a fan blade hitting metal type noise but can't pinpoint it. It's not the fan hitting anything, it's tight, no wobble. The problem is hard to recreate and only happens at times. Seems to only do after truck is fully warmed, after slower speeds and maybe a little lugging of engine. I can idle it or rev it all day and it never happens. When it does happen out on the road I stop to check and before I pinpoint it it goes away. I wonder if it could be the WP impeller blades but that should do it all the time and it's new. Hate to pull it apart again and loose all the fluid and all that work to find nothing.

Sorry I know n one can help, just need to ramble a little.

 

I had a similar problem on my wife's Jeep after I changed the radiator. The bottom of the radiator shroud had 2 ears on it that sat in holes below the radiator. I didn't get one of them in the hole and the shroud was slightly loose and moved on that side when I hit bumps. It also made noise off stop signs (under load) because the engine moved in the mounts more under load than when it's just sitting there and revving.
I think my 97 Expy shroud has 2 ears on the sides of the shroud that sit in pockets on the sides.

 

Good idea to check. I did take the shroud out and there is two tabs it must slide into. I have checked the blade and the shroud and didn't see any scrape marks.