2005 Dodge Durango Hemi 5.7 Fan Clutch Issue?

[qtla9111]

The SUV has 262,000 miles on it and it has driven and towed beautifully over the 12 years we have had it and still looks great.

There has always been an issue with what I have believed was the fan clutch. At intermittent times, mostly towing in the mountains, the engine begins to roar and it becomes more difficult to accelerate. The more you accelerate the more it sounds like a jet engine. The temperature gauge never changes. I have recently checked the engine temperature with a laser gauge I use on my tires and it registered 217F. Some websites say that's a normal range and as I said, the temperature gauge doesn't increase.

Recently I had the fan clutch changed out. Now it seems to happen more than before. At startup (even with a cold engine), the engine roars as I accelerate taking off. The radiator fan is spinning and the fan clutch as well. At around 35 mph it disappears and the RPMs reduce. When towing, it does the same thing but once past 35 or 40 mph it seems to disappear again almost as if it is cooling off or something.

What should I be looking for? I'm at my wits end with this.

Thanks in advance for any suggestions you might have.

[Johno02]

Just so you know, If a fan clutch dies in a situation that you can't replace it immediately, in most cases you can drive the vehicle by removing the fan from the clutch. If you are open road driving, without and stop and starts. Generally, ambient air flow through the radiator will keep it cool enough. If you stop moving, such as a rest stop, it will overheat VERY quickly. One time, we drove over 300 miles on the interstate from Knoxville to down below Nashville, temps in the 80s, even were able to run the ac without over heating. One gas stop, and it was getting hot just from the exit ramp to the pumps. Back on the road, it cooled down just fine.

[ScottG]

After recently replacing my fan clutch, I actually like hearing my fan make those sounds. Like Matt wrote, if it doesn't roar, it needs to be replaced. Same goes with it roaring in the mountains. The noise is a good thing!

[Matt_Colie]

Well, You have just discovered something that I knew when I worked at that company. Cooling fans use a lot of horsepower and make a lot of noise. Unfortunately, there is no workable cure.

The fan clutch responds to the temperature of the air coming through the radiator and not the engine temperature as measured by normal equipment. The roar at start up is an artifact of the viscous clutch. They all do that until they die. When it fails to do that, replace it.

Best of luck.

Matt

[ScottG]

There's nothing to fix, the fan is working absolutely perfectly.
That is exactly how a heavy duty clutch fan should function on a Dodge and yes, a new one will roar even more becuase as they age, they loose efficiency and spin slower for a given eng speed.


Scott