Your Car's Fan Clutch Provides the Heat Needed for Winter Driving

If you should find the heater in you car is not performing up to your expectations this winter there are a few things you can do to correct the problem.

First, determine if the coolant level in the radiator is correct. If the level is correct or if after filling the radiator to the proper level fails to bring your heat back, the next likely suspect is the thermostat. This little device is constantly adjusting itself and eventually wears out. And usually it gets stuck in the open position...which, while your engine will not overheat..it will take forever to get up to operating temperature..and you get barely warm air on your cold fingers. These are usually easy to replace and not expensive at all. It may fix your problem.

The third place to consider is the heater core itself. This is a little radiator buried up under your dash and you probably want to let the repair shop look into the problem if you suspect this thing has gone bad. The heater core tends to fill up with rust and sediment over time and hot water cannot circulate through them...so..you have no heat.

The last item I will mention is the radiator fan. Many cars these days have an electric fan and it will turn on and off as needed. But if it runs all the time...you may find your interior heat is lacking because it is cooling off the hot engine coolant too fast. Pull the plug on this fan if you suspect it is running too much and see if your heat comes back. And if your heat returns, then you probably need a fan thermostat. Not to be confused with the coolant thermostat. Two different items there.

Now..on engines that have the fan driven by a belt..like most rear wheel drive cars and trucks will have..the fan deal is a slightly different story. These engines use a fan clutch. This clutch also has a thermostat built into it and will cause the fan to engage when the engine is hot, such as when you are idling in traffic,towing or doing a lot of lower gear driving. To look at the fan it appears to me moving at all times..even when the engine is cold. But the truth of the matter is, the fan, even though it is spinning at all times wont fully engage and begin really spinning until the engine reaches a certain temperature, and then it FULLY engages and begins drawing large amounts of air through the radiator, thus lowering the coolant temperature. If that clutch goes bad, you will know it when cold weather arrives.

I did everything previously mentioned trying to get my heat to come back and sooth my cold extremities this year. I checked the coolant level. I replaced the engine coolant thermostat. I replaced the heater core. Still had barely warm air coming inside from the heating system. Then, I noticed that I was getting a grinding noise from the engine on occasion..usually when I hit a high rev..in a lower gear.

Checking through some web searches for a combination heating problem and grinding noise, I discovered the fan clutch might be faulty. Given that my rattle trap is 16 years old..this seemed a very likely possibility. It also offered a handy test to determine if the fan clutch needs to be replaced. Just pop open the hood and with the engine OFF...try to spin the fan. You don't need to put too much pressure on the fan here..it SHOULD move easily..maybe a few rotations before stopping. If it is stiff and difficult to move...that clutch is engaged all the time and sucking huge quantities of cold winter air through your radiator...and thereby reducing the amount of hot coolant treated air your frosty toes need inside your vehicle.

It is expensive too. The fan clutch for my vehicle cost nearly 70 dollars. But, I did get a good one, I don't want to have to do this again next year by getting a fan clutch for half the cost and wind up spending the same amount of money again, and having to work on the vehicle twice. The replacement of the fan clutch is usually straight forward. In my case, I had to remove the top half of the fan shroud to give myself clearance to the fan. Then, four nuts hold the fan to the pulley. The fan comes off and then four bolts hold on the clutch which is attached to the fan. Very easy repair and it took maybe 45 minutes with common hand tools.

So how is my heat? It is coming back. The new clutch is just that..new ! So it is just a bit stiffer than it will be say 3 weeks down the road. And it will continue to loosen up over time until it attains maximum operation. These clutches also have a highly viscous fluid inside them to help them work correctly and it takes time for it to thin out a bit with use.

I hope this article has been helpful to you and good luck on your repairs.