How to diagnose a fan clutch?

How to diagnose a fan clutch?

My truck on Expressway just gets only t 40 or60 miles per hour.in winter time with engine off fan clutch truck is operating, which means my truck last to long to warm up.truck sounds roughly also,truck consume to much gasoline as well,. theres another thing, my power steering switch is broken also,i know this detective switch causes poor engine performance (power steering switch).and i would like more especificaciones información to diagnose fan clutch,how to diagnose this engine cooling problem,this poor engine performance,this excessive gas consumption, etc, please help me up with some in

Experienced mechanics share their insights in answering this question :

If the fan clutch is a thermostatic type then you should be able to start the vehicle cold and using a shop towel, dangle it in the fan blade while keeping your hands clear, to see if the towel stops the fan blade. It should stop it. Now remove rag from the fan and let engine warm up, running the engine at 1500 rpm. The engine should get to operating temperature within 3 minutes. If it takes longer than four or five minutes and the fan still checks okay at idle, then you have a stuck open thermostat. Replace the fan clutch if it locks up all the time or if the fan wobbles too much. With the engine off, the fan should spin when cold and now wobble back and forth. If it’s proven to be faulty and you need some help with the replacement of your fan clutch, consider YourMechanic. A certified technician will be able to come to the vehicles location and service your car.

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To confirm the diagnosis, start with this simple test: Spin the fan as hard as you can on an engine that has not been started that day. If the fan rotates more than five times, you can bet the clutch is bad. You should feel some resistance and the fan may spin up to three times, depending on the ambient temperature.

Most fan clutches are filled with a silicone-based oil. The oil is held in an internal reservoir when the fan is disengaged. To engage the fan, internal valves open and allow the fluid to fill the working area of the clutch. This creates friction between the drive plate and the housing, causing the fan to spin.

Spring-operated fan clutches sense temperature from the bi-metal on the front of the fan clutch and electronically-controlled fan clutches are controlled by the vehicle`s Engine Control Unit (ECU), which measures temperature from sensors throughout the engine bay.

While there should be a little bit of give, it shouldn`t spin more than three complete rotations. Too much free-wheeling is usually a sign that the clutch is prone to slipping. On the other hand, too much resistance means the clutch is binding and can`t turn freely. In either case, it will need to be replaced.

At what temperatures do fan clutches engage? Answer: Most fan clutches engage at about 170°F air temperature (about 180-190°F engine temperature). They reduce the temperature about 20°F before disengaging.

You should not drive or run the vehicle if the cooling fan is not moving or the engine may overheat and cause severe damage. Have the cooling fan and fan clutch checked to make sure it is working properly.

Understanding the Hub/Clutch Relationship

The first piece is the Fan Hub, which consists of an assembled pulley and mounting bracket. The second piece is the Fan Clutch, which turns on and off as needed to cool the engine.

A proper water pump replacement should include a new fan clutch as the two are connected to the same shaft and work together to move the air and cooling fluid. Replacing one without the other can damage the new part and cause repeat work or engine trouble.

Whistling. A whistling or whining noise coming from the engine bay can be pretty serious. There`s a number of possible causes for the whistling noise, but one of the most common causes is a loose serpentine belt. When this happens, the fan clutch is not engaged properly.

Fan speed is controlled with thyristor or transformer speed controllers. Thyristor speed control. Thyristor speed controllers provide smooth manual motor speed control and air flow control respectively. Operation of the thyristor speed controllers is based on output voltage control with a triac voltage regulator.

Fan Clutches are `fluid` coupling devices that provide air flow through the radiator by using the water pump shaft to power the fan blade. When the pump is cool or at normal operating temperature, the fan clutch will partially disengage.

Absolutely, a bad one can damage your air conditioning system, as it acts as a heat exchanger for the air conditioning unit. The engine fan keeps the condenser cool which helps to keep the convertible`s AC system running smoothly.

A thermal fan clutch is engaged on a cold startup because the fluid drains into the working area when the engine is shut off. The fan clutch will slow down shortly after startup as result of a pumping action produced by a difference in speed between the shaft and the body of a clutch.

There is no set mileage that this part will last, rather it`s important to watch for early warning signs that it may be giving out. While there are times you can repair the fan clutch, in most instances it`s best to replace it.

Overheated engine: If the fan clutch is stuck in the “off” position, the engine will overheat. Heater not effective: If the fan clutch gets stuck on in cold weather, the engine will take a long time to get to its normal operating temperature.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

When replacing my fan clutch should I change my cooling fan to a flex-a-light and get a new flex-a-light clutch?

ANSWER : Hi there. It is best to always put on the OEM parts that are required for the vehicle. However, you can get a flex-a-light clutch fan for your vehicle as long as it will bolt up to your water pump pulley and clear the radiator and shroud. I recommend having a clutch design fan for your vehicle and not a fan that spins with the engine all the time. Those fans will cause the engine to overheat on highways and in town especially in hot weather. If you need further assistance with your cooling fan, then seek out a professional, such as one from Your Mechanic, to help you.

Read Full Q/A … : How to diagnose a fan clutch?

With the electronic fan clutch, is it normal to have the fan clutch barely running and that you can keep it from turning with one

ANSWER : Hello. This is normal operation of the fan clutch. The electronics should turn it on as needed. This saves on the power loss that is associated with the fan when it is needed to keep the engine cool. This increases the fuel mileage of the vehicle and can disable the fan for short periods when you need the extra power like accelerating up and on ramp to the highway or passing a vehicle. Unless you are having an issue with the cooling system or the A/C not working correctly then you should have no worries.

Read Full Q/A … : How to diagnose a fan clutch?

How to diagnose a fan clutch?

ANSWER : If the fan clutch is a thermostatic type then you should be able to start the vehicle cold and using a shop towel, dangle it in the fan blade while keeping your hands clear, to see if the towel stops the fan blade. It should stop it. Now remove rag from the fan and let engine warm up, running the engine at 1500 rpm. The engine should get to operating temperature within 3 minutes. If it takes longer than four or five minutes and the fan still checks okay at idle, then you have a stuck open thermostat. Replace the fan clutch if it locks up all the time or if the fan wobbles too much. With the engine off, the fan should spin when cold and now wobble back and forth. If it’s proven to be faulty and you need some help with the replacement of your fan clutch, consider YourMechanic. A certified technician will be able to come to the vehicles location and service your car.

Read Full Q/A … : How to diagnose a fan clutch?

Car will overheat if I don’t have the fan on. When fan is off it doesn’t come on to release heat from engine. So the fan is always on.

ANSWER : Check the wiring to the coolant temperature sensor and see if there is power to the sensor switch. If there is no power, then check the cooling fan relay and see if its clicking on. If there is no clicking motion, then remove the relay and check for power to the relay. If there is power to the relay, then the cooling fan relay needs replaced. If there is no power to the relay, then check the fuse. If the fuse is burned, replace the fuse. If the fuse is good, then check power from the fuse to the main circuit on the fuse box. If there is no power, then the fuse box needs replaced. If the fan comes on with the air conditioning system switch turned on, that is because the switch overrides the cooling switch to make the condenser cool down to make the air conditioning system work properly.

If you need further assistance with your cooling fans not coming on when the engine gets hot, then seek out a professional, such as one from Your Mechanic, to help you.

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I can’t go into 4th or 5th gear and clutch does not engage after a recent clutch job, clutch release while in gear does nothing.

ANSWER : I would rule out the axle not being pushed all the way in. That would effect all speeds and gears. That you can engage gears other than 4th and 5th leads me to 2 m possibilities:
1. Shift linkage mis-adjusted.
2. Possible bent shifter fork internally.

If it feels like you can engage 4th and 5th with the engine OFF, then I would lean towards a clutch release issue.

Read Full Q/A … : How to diagnose a fan clutch?

My cooling fan won’t turn on when I turn the ac on. Relays and fuses are good, tested the fan with the battery and it came on??

ANSWER : Hi there. In general, a situation like this occurs when either the thermostat housing or temperature sensor is not relaying the information to the fan motor to activate. However, it’s also possible that there is some electrical short within the cooling system relay’s that is causing the fan motor to not activate when it should. I think the best way to determine the precise source of this problem is to have a professional mechanic come to your location to complete an onsite inspection so they can test all systems to help isolate the root problem and recommend the right repairs.

Read Full Q/A … : How to diagnose a fan clutch?

Ac compressor clutch isn’t engaging on high fan speed setting while it engages on the prior three fan speeds which are all slow.

ANSWER : The blower not working is most likely due to a fault with the blower resistor. When you go to high blower speeds the A/C may disengage the compressor if the cycling switch cycles or the high pressure switch gets over pressurized, shutting the compressor off. The first thing to do is to get the blower working correctly then test the A/C pressures using A/C gauges. If you’d like to get this fixed, consider YourMechanic, as a certified technician can diagnose your A/C issue and fix it accordingly. Good luck.

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Clutch pedal stays to floor. Replaced master cylinder. Clutch push rod broke. Also do I need to change slave cylinder

ANSWER : If you have an issue with your clutch pedal going to the floor, the slave cylinder is normally the cause of this circumstance.

Also, if the push rod has been broken the first step would be to track down a new one because that push rod is a very necessary part of the clutch pedal system.

Once a new push rod has been located and installed, I would recommend having a new slave cylinder installed as well.

If you are in doubt about this repair, I would recommend having it performed by a qualified professional, such as one from YourMechanic. One of our mobile technicians will be able to come to your home to diagnose the issue with your clutch pedal and replace your clutch slave cylinder as necessary.

Read Full Q/A … : How to diagnose a fan clutch?