I just bought a 2002 Chevrolet 1500HD with a 6.0. I notice that the fan is alot louder than most. At first I thought my transmission was making the noise, but after a little inspection it is coming from from the fan. The fan seems to be a little stiff, but the truck doesn't run hot at all. Should the fan free wheel at all when you stop the motor. This one comes to a very quick stop (I was by myself checking it and tried to shut the motor off and see the fan moving and no matter how fast I move to see it the fan was at a complete stop by the time I made it the 5 feet to the front). How should I check the clutch? Has anyone put newer style electric fans on one of these?

 

Wd-40!!!!!

 

...seriously? lol

People put e-fans on them all of the time. They improve fuel economy and free up a little but of horsepower as well. You might keep your eye out for an '05 or newer set of stock e-fans. Bolt right in, just have to wire them up. Mine are wired to an ignition fuse, so key on = fans on.

 

Sounds like its a non-thermal clutch. Meaning its gonna pull air all the time. Thermal fans will allow slippage and then pull air when it gets hot. I bet when you rev it, you can hear it whine huh? If the the fan keeps spinning when you shut it off then the more than likely the clutch is burned up.

 

From the research I have done the fan should be fairly quiet until it reaches a certain temp and then it should get a little louder. I replaced a 2001 2500HD with this 2002 1500HD. They have the same drive train so I would expect them to have the same amount of fan noise. I am wondering if either this truck has an aftermarket clutch (which I hear will lock up alot sooner) or the factory clutch is beginning to seize up. I will let you guys know what I find. Thanks for the input (especially the WD-40 idea) LOL!

 

Hey have you thought of putting a flex fan?

 

Don't put a flex fan on it. That is only for the really hot running motors. If you think yours is loud now, wait till you hear a flex fan! They sound like a jet engine.

You should be able to feel the fan turn with the engine off. Just grab it and turn it, then move it in the directions it is not sapposed to turn, make sure that it is good and tight.

If you have a direct fan it will not spin at all, and you should be able to see that it is directly mounted on the front of the water pump. If you have a fan clutch, then you should be able to turn it, but it should feel like a soft shock does, it shouldn't turn freely but shouldn't be locked up either. Like I said, like a soft shock would feel in it's movement (kind of like moving fluid through a small hole, slow but smooth no matter how hard you press). You will also be able to see a big silver housing in front of your fan blades towards the radiator.

 

I think some people are pretty ignorant when they look into applying a flex fan and forget to use the RPM application for the right motor. If its making noise, then its pulling air. Take the stock fan and clutch in one hand and a flex fan in the other and tell me which one weighs less?? But IMO, its the better for towing, which is what I think he is going for, but please correct me if I am wrong.

 

If you are talking about weight and power then you should look into an electric fan, they are capable of keeping your engine very cool, use less space and less parasitic loss for cooling. That and after about 55mph you shouldn't need any fans on at all, that is why they should be temperature controlled, not direct. IMO (and the opinion of most vehicle manufacturers)

So in this case, once the problem is located, he should either fix the current set-up or upgrade to an electric fan. Depending on what he/she wants to do with the vehicle will depend on what they want to do for cooling.

IMO for drag racing-the optimal thing to do would to go to an electric water pump, electric fan, and go to an isolated battery system with no accessory drive at all. (No power steering pump or AC system. (No charging system at all)

But if you plan on driving this thing at all (off the track), then you will need to keep the practicality there. This means going to the most efficient systems, that means limiting the amount of parasitic loss at the source.

So for who is trying to keep up with the subject, which do you think is better?
Electric fans (Mounted directly to the radiator and thermally switched),
Direct drive fans (flex style fan, belt driven) or
Clutch limited fans (thermally controlled, belt driven)

Input would be much appreciated!

For this thread though, I would still like to hear what is really wrong with the truck in question. So if Mr. Shamrock still has questions or if you find the problem I will be looking for your posts to see what is up!

Also are you using the truck for towing?? I didn't see you mention that.

 

I'm in Texas, therefore my efans (35'') are wired directly so that when they key is on, the fans are on. Even at highway speeds (and even if I didn't have a turbo under the hood) I would (and always have) ran it that way. There's slim chance the engine is going to get "too cool". It's still practical with no negative effects.