Z31 Fan Clutch Replacement
The clutch fan is a very nice invention compared to a non clutch type fan. A clutch type fan allows the fan to freewheel when the tempature of the motor is low and then spin when tempatures reach a set point. Most of the time it wotks well. When it fails the symptoms may vary from overheating only at idle or highway speeds to excessive fan noise. It can also destroy a perfectly good water pump.
Clutch Fan: Common Symptoms & Inspection
Symptoms of a failing clutch fan can vary widely:
- Slipping under load due to fluid loss
- Overheating at idle, but normal cooling at highway speed (or vice versa)
- Consistent overheating under all conditions
- Lockup when hot — causing excessive fan speed and loud noise
Here are a few things you can check to determine if your clutch fan is the culprit:
- Inspect for oil residue on the outside of the clutch body
- With the engine off, wiggle the fan side-to-side to check for play
- Try spinning the fan by hand. It should turn freely. If it spins more than half a turn, it may be low on fluid
If you’re dealing with persistent overheating and can’t trace the cause, the **thermostatic clutch** may be at fault. Since it's mounted directly on the water pump, a bad fan clutch can wear out pump bearings over time due to imbalance.
Clutches generally cost between $30 and $60. If you're stumped by a mysterious overheat issue, replacing the fan clutch is a low-cost potential fix worth considering.
Replacing The Clutch
Replacing the Fan Clutch is not all that hard. Remove the plastic cowling from around the fan. There is the one bracket on top and several metal clips securing the bottom. Hang on to the clips. You'll have to Wiggle the cowl around to get it off and around the fan. Next remove the four 10mm nuts holding the clutch in place. (see image top) Be careful not to remove the pulley. The pulley is held on by the same nuts. If the pulley Comes off you will need to loosen the fan belt to get it back together. Once the clutch is off reverse the order of disassembly to install the new one. Put this metal clips back on the bottom. The top edge of the cowling hooks onto a groove on top.
Hope this helps with overheating issue or a noisey clutch fan on your Z31