4.7 clutch fan noise driving me nuts

[mad11ram]

So, I get bad clutch fan noise, but the thing is I have already replaced it twice. This only happens on 80°+ days when the motor gets hot. In the winter theand in morning or evening the truck runs and shifts fine, but once it gets hot the shift points change and it sounds like my engine is going to blow. I've flushed the trans and replaced the trans cooler/ac condenser, radiator, thermostat and fan clutch x2. I'm at a complete loss. The engine temp stays pretty constant, but I can tell an obvious difference between hot and cold days.

 

[Tach_tech]

Was it an OE part of aftermarket? I’ve seen a lot of issues with aftermarket fan clutches. They will be noisy when fully engaged though.

 

[mad11ram]

All oe replacement parts. Truck has almost 200k I've only had it for 60k. It has behaved this way in the heat since I have owned it, but now I am trying to squeeze every bit of life out of it and try to avoid a major malfunction.

Was it an OE part of aftermarket? I’ve seen a lot of issues with aftermarket fan clutches. They will be noisy when fully engaged though.

 

[Tach_tech]

If it’s been doing it since you’ve owned it, I wouldn’t worry to much about it.

It appears to be working as designed. When the clutch is fully engaged it will increase load on the engine so it may cause shift points to be a little different. The noise can be annoying but it’s doing it’s job.

 

[Gr8bawana]

If it’s been doing it since you’ve owned it, I wouldn’t worry to much about it.

It appears to be working as designed. When the clutch is fully engaged it will increase load on the engine so it may cause shift points to be a little different. The noise can be annoying but it’s doing it’s job.

It is not the fan clutch you're hearing, it's the actual fan noise from all the air being moved after the fan clutch locks up when it reaches whatever the temp threshold is.

 

[Tach_tech]

It is not the fan clutch you're hearing, it's the actual fan noise from all the air being moved after the fan clutch locks up when it reaches whatever the temp threshold is.

Absolutely right. You’re not going to hear the clutch, it’s the air moving, and when the clutch is fully engaged they move a LOT of air.

 

[mad11ram]

It is not the fan clutch you're hearing, it's the actual fan noise from all the air being moved after the fan clutch locks up when it reaches whatever the temp threshold is.

Would an intake and exhaust decrease the amount of heat that builds up? My issue is the truck has a hard time pulling its own weight at 75 mph on hot days, I want to buy a small camper and I don't want to be doing 55 on the interstate. I plan to get a newer truck in the next year so I don't want to get crazy with it, but I'd really like a truck that can functionally pull up to 5k# this summer.

 

[Fast69Mopar]

I agree with the other posters. What you are hearing is the large amount of air that is being pulled into the engine compartment by the mechanical fan. Its entirely normal. What are your engine temps at idle when fully warmed up? What about cruising the interstate at 70mph? What is the condition of the radiator? Was it a Mopar part or parts store or 1-800-Radiator? Did you look at the temp of the thermostat marked on its housing?

Have you ever thought about switching to an electric fan setup to eliminate the mechanical fan? There are some really nice dual fan assemblies in their own shroud that will bolt directly in place of the factory shroud. It would eliminate the high volume fan noise you hear and eliminate some parasitic loss on the engine from not having to drive the fan. They can also be thermostatically controlled and you can set the fans to engage at whatever temp you want.

 

[Gr8bawana]

The OP states that he doesn't want to spend a lot of $$ since he is getting a newer truck. Going to electric fans will take some $$. Also when the fan clutch is basically free-wheeling so there is very little drag from the fan.

To the OP-if the temp stays constant as you say then it is all working as intended. I would only worry if it was over-heating.

 

[Fast69Mopar]

For the money the OP spent on flushing the trans and replacing the trans cooler/ac condenser, radiator, thermostat and 2 x fan clutches he could have had a really nice electric setup.

 

[crackerjack1957]

Would an intake and exhaust decrease the amount of heat that builds up? My issue is the truck has a hard time pulling its own weight at 75 mph on hot days, I want to buy a small camper and I don't want to be doing 55 on the interstate. I plan to get a newer truck in the next year so I don't want to get crazy with it, but I'd really like a truck that can functionally pull up to 5k# this summer.

Post coolant, trans & engine temps when fan clutch pulls hard.
If it's really hot, timing will retard & power is lost.
How many miles on plugs & air filter?