If you can spin your fan freely after shutting off a hot engine, then yes, it sounds like your clutch is shot. That could be your whole problem.
If you have a non-thermal, it's controlled by rpm's. At idle, the clutch is locked up, and provides the most pull on the radiator. As the revs go up, the clutch begins to disengage, as you don't need a solid, locked up fan at highway speeds.
If you have a thermal, then you'll see a curly spring in front of the clutch. When temps get hot, the spring engages the clutch, and the fan is locked up. As the revs increase, the thermal clutch behaves like a regular clutch fan, and will nearly freewheel at highway speeds.
Not sure of the factory fan will bolt up to the Hayden clutch. I bought the Hayden 18" black fan when I bought the clutch. Been using it for many years now.
A rule of thumb on your current clutch fan:
- When the engine is cold, and the engine is off, if you can flick a blade with your hand, and the fan spins more than 1/2 a revolution, the clutch is starting to go. If the fan spins an entire turn (or more), then the clutch is shot.
- With the engine hot (at idle), shut the car off. The fan should stop immediately. If it continues to spin a few revolutions, the clutch is shot.
Mike
I have the thermal clutch installed. It doesn't spin freely or without resistance when cold. I just got back from out of town and went out and tried to spin it. It moves but stops quickly. Which it should because it has only about an hour or two of running on it. Tomorrow I will run the car and get it warm again and see how it does. As I mentioned last post or so, when the engine was very hot and almost overheating I turned the ignition off and the fan acted as it does now and I could move it. As I also said, someone said that it should remain engaged until it cools and it would not cool immediately.
I will also try and check my timing and see if my advance is working. That is one of the only items I did not replace from the engine. Seems stupid now. I have an aftermarket 18" 6 blade fan but I don't know if it is worth trying to hunt down a 7 blade. I am trying but I can not find any anywhere. Where do we get these OEM 19 1/2" 7 blade fans?
Also, I just looked up the pulley sizes needed on the chart that was recommended and I think I have the wrong sizes. My car was originally a non-AC car and only had Power steering. So when I go into the chart that is listed here Belts and Pulleys . It looks like I may have the wrong Water Pump pulleys. I may have 8" pulleys instead of 7 3/16 (see last page 69 Firebird, V8, Power steering vs AC Power Steering. Would that make much difference?
