What causes the fan clutch to lock up?
Engaged Mode This mode causes the silicone fluid inside the fan clutch to move from one chamber to another, thus causing the fan clutch to lock up and turn close to engine RPM speed. This mode is the one that provides the maximum cooling effect by pulling the most air across the radiator and A/C Condenser.
How to troubleshoot a bad thermal fan clutch?
The Complaint. Troubleshooting Begins. Quickly Checking For A Blown Head Gasket. Quickly Checking The Thermostat’s Operation. Checking The Fan Clutch. Manually Locking Up The Thermal Fan Clutch. Manually Locking Up The Thermal Fan Clutch (Part II). Fan Clutch Troubleshooting Summary. A bad thermal fan clutch will cause your vehicle to overheat.
How is the bimetallic coil connected to the fan clutch?
This bimetallic coil is connected to a shaft that runs inside the fan clutch assembly. The bimetallic coil is designed in such a way that when exposed to the engine’s increasing heat, it begins to expand.
What causes a fan clutch to go clockwise or counter clockwise?
This decrease in temperature causes the coil to contract and so the shaft now rotates clockwise (and thus back to its original position). This counter-clockwise and clockwise rotation of the shaft, as the bimetallic coil expands and contracts, causes the fan clutch to go into one of two modes of operation:
How much does a GMC Envoy check engine light cost?
The average cost for a GMC Envoy Check Engine Light Diagnosis & Testing is between $88 -$111. Learn More Good news! We found 32 RepairPal Certified shops near you.
Why does my envoy idle at 600 rpm?
These motors idle at 600 RPM give or take and a worn motor mount will produce a felt vibration at idle that goes away just above idle. If you have never changed the mounts, I would consider that a possibility. Only use AC mounts, the aftermarket is very hit or miss, biased to miss, on damping the 10 Hz frequency at idle.
Do you need an OEM Service Manual for envoy?
Only use AC mounts, the aftermarket is very hit or miss, biased to miss, on damping the 10 Hz frequency at idle. He did say he replaced the mounts with OEM. Need GMT360/370 Service Manuals?
Why is my car’s cooling fan clutch not working?
Fan clutch intermittently locks up creating noise and check engine situation. The code reads cooling fan speed too high. Replacement fan clutch does same thing. Check Engine Light illuminated and took the car to the dealer to have it checked. They ran a diagnostic test and said the Cooling Fan Clutch needed to be changed. Cost $1185.00. Outrageous!