What happens when a bad fan clutch goes bad?
What happens when a bad fan clutch goes bad?
When a fan clutch goes bad and causes your vehicle to overheat, it’s usually because the fan clutch is unable to get into its ‘Engaged’ mode. Thankfully this can be tested (indirectly) by manually locking the fan clutch into its Engaged Mode and I’ll show you how in this case study. What Vehicles Can I Apply This Info To?
Can a GMC one ton engine overheat?
But I had experienced better: that 1980 GMC one-ton. It never overheated once, under any condition. I was already aware of a GM service bulletin (06-06-04-036D) addressing overheating in extremely hot ambient temperatures. The bulletin applied to all 2004 and 2005 LLY Duramax engines.
Why is my Duramax LLY overheating at 50 mph?
The fan clutch on that old gasser would never engage at speeds above 50 MPH, even in the hottest ambient temperatures and towing the heaviest loads. Above that speed, there was always enough airflow over the radiator to keep the engine quite cool.
When does the cooling fan engage on a Duramax LLY?
After towing for a few hours, I could very easily predict the behavior of the cooling fan. With every short hill I pulled, the fan clutch would engage for about three to five minutes near the top or after I crested the hill.
Can a bad fan clutch cause engine overheating?
A bad fan clutch may not engage properly or at all, and as a result, will disable the fans or prevent them from working at maximum efficiency. This may result in the engine overheating, which will lead to more serious issues if left unattended.
What should I do if my fan clutch fails?
When it fails, the engine can be put at risk of serious damage due to overheating. If your vehicle is displaying any of the symptoms above, or you suspect that your fan clutch may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the car will need a fan clutch replacement.
The fan clutch on that old gasser would never engage at speeds above 50 MPH, even in the hottest ambient temperatures and towing the heaviest loads. Above that speed, there was always enough airflow over the radiator to keep the engine quite cool.
But I had experienced better: that 1980 GMC one-ton. It never overheated once, under any condition. I was already aware of a GM service bulletin (06-06-04-036D) addressing overheating in extremely hot ambient temperatures. The bulletin applied to all 2004 and 2005 LLY Duramax engines.
What makes up a thermal fan clutch shaft?
In a nutshell: There are two major components that make up a thermal fan clutch: A reservoir filled with Silicon fluid, that’s inside the fan clutch itself, and a bimetallic coil on the outside. This bimetallic coil is connected to a shaft that runs inside the fan clutch assembly.
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 long does it take for a fan clutch to come to life?
After 4-5 minutes, the fan clutch should come to life. Assuming it doesn’t, or that it’s sluggish when it finally gets moving, it may be on its last legs. The same is true if the fan speed accelerates as soon as you start the vehicle.
What happens if you have a bum fan clutch?
A bum fan clutch drains horsepower from the engine to keep the mechanical fans running, which can ultimately lead to critical overheating, decreased fuel economy, and poor general performance. Thanks!
Is there a case study for a bad fan clutch?
Although this is a case study of a 2003 Chevy Express Van (with a 6.0L) that belongs to a buddy of mine (Oscar), you can apply the testing tips and info to any thermal fan clutch equipped vehicle. So, whether you’re driving a GM 4.3L, 4.8L, 5.0L, 5.3L, 5.7L, or any Ford, Chrysler vehicle, etc., this info will help you.
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.
In a nutshell: There are two major components that make up a thermal fan clutch: A reservoir filled with Silicon fluid, that’s inside the fan clutch itself, and a bimetallic coil on the outside. This bimetallic coil is connected to a shaft that runs inside the fan clutch assembly.
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.
When a fan clutch goes bad and causes your vehicle to overheat, it’s usually because the fan clutch is unable to get into its ‘Engaged’ mode. Thankfully this can be tested (indirectly) by manually locking the fan clutch into its Engaged Mode and I’ll show you how in this case study. What Vehicles Can I Apply This Info To?
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:
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.
