A/C not cooling, engine overheating
#2
11-04-2012, 07:13 AM
#3
11-04-2012, 09:57 AM
Mudding
You will find lots and lots of threads on Land Rovers with engine temperature problems. They're known for it, but it's usually an easy fix. Your vehicle is not that old, so I'd guess that it's not the radiator or water pump. Unless you have very high mileage for its age.
It could be a stuck thermostat, worn out belt or tensioner, possibly even low coolant, among other things.
It could be a stuck thermostat, worn out belt or tensioner, possibly even low coolant, among other things.
#5
11-04-2012, 11:20 AM
Well the a/c works when I'm driving and moving but at a stop it quits working. This started this past Tuesday but the engine issues started just yesterday from what I can tell. Made several stops yesterday (running errands) and shut off the engine but after a couple of stops the engine didnt have a strong start and the a/c did not cool until I was moving. Then finally after another stop I noticed the engine temp light came on and the gauge pointed to red. Engine was off for about 30 min then started (not strong) and made it home at normal temp but I did not turn a/c on. Haven't started it today. I'm scared to. Help please!
#6
11-04-2012, 01:38 PM
Mudding
There's only one serpentine belt. It's around $50 at Advance and can be replaced in the parking lot in under 15 minutes. Also be sure to check your electric fan, as previously mentioned. With the A/C on, hold a plastic grocery bag in front of the truck. It should get sucked up to the grill.
#7
11-04-2012, 02:42 PM
Ok I just went out and looked under the hood and I see a belt but how do I change it out? Looks complicated because of where it is. And would the belt have anything to do with the a/c? Everything under the hood looks like its difficult to get to. With any suggestions I need to know where to look under the hood.
Last edited by LaGirl; 11-04-2012 at 03:09 PM.
#8
11-04-2012, 05:24 PM
TReK
You have a volvo derived engine. Did you ever have the recall for the coolant hose replaced? if not try that. But its possible you have an issue with the radiator fan and or the module that controls it. You need to have it diagnosed before throwing parts at it. plus changing parts at that engine requires certain special tools because of the design of the engine.
#9
11-05-2012, 05:41 AM
#10
11-05-2012, 07:06 AM
Super Moderator
LR2 - aka Freelander 2 would be somewaht different from an Freelander because of the Volvo motor.
In the Freelander original - would have electric cooling fans only, and some fuses to protect them, relays and modules to activate them. If fuse is blown, could indicate one or both fan motors is starting to sieze up. With battery disconected spin electric fan blades, they should both turn freely. Fuses to check are inside engine compartment box. The coolant pump is belt driven, but by the cam shaft timing belt, where it also acts as an idler pulley. So poor coolant maintenance that results in a siezed water pump will also take out the timing belt, resulting in engine damage. IMHO when you change timing belt you should change water pump.
So in an Freelander (or any vehicle with only electric fans) you could drive on highway at speed without fans running, but will overheat quickly in other driving consitions, like stop and go, etc. In a pickle, you could slap an after market electric fan on the front and wire it with a fuse to the battery to run constantly, until real repairs could be made.
Here how the fans work, which as mentioned in another post, is complex. Designed for most cooling as needed, least noise, etc.
requested speed. As part of the power down routine, when the ignition is switched off, if the ambient air temperature is more than 15
In the Freelander original - would have electric cooling fans only, and some fuses to protect them, relays and modules to activate them. If fuse is blown, could indicate one or both fan motors is starting to sieze up. With battery disconected spin electric fan blades, they should both turn freely. Fuses to check are inside engine compartment box. The coolant pump is belt driven, but by the cam shaft timing belt, where it also acts as an idler pulley. So poor coolant maintenance that results in a siezed water pump will also take out the timing belt, resulting in engine damage. IMHO when you change timing belt you should change water pump.
So in an Freelander (or any vehicle with only electric fans) you could drive on highway at speed without fans running, but will overheat quickly in other driving consitions, like stop and go, etc. In a pickle, you could slap an after market electric fan on the front and wire it with a fuse to the battery to run constantly, until real repairs could be made.
Here how the fans work, which as mentioned in another post, is complex. Designed for most cooling as needed, least noise, etc.
Cooling Fan Control
The ECM controls the operation of the variable speed cooling fans via a Pulse Width Modulated (PWM) signal to the
cooling fan ECU. The cooling fan ECU regulates the voltage of a common power feed to the two fans, and relates the
voltage to the duty cycle of the PWM signal.
The ECM controls the operation of the variable speed cooling fans via a Pulse Width Modulated (PWM) signal to the
cooling fan ECU. The cooling fan ECU regulates the voltage of a common power feed to the two fans, and relates the
voltage to the duty cycle of the PWM signal.
The ECM varies the duty cycle of the PWM signal between 3 and 90% to vary the cooling fan speed. At duty cycles
between 3 and 9% the cooling fans are off. When the duty cycle goes above 9% the cooling fans come on at minimum
speed, then increase in speed, in proportion to the increase in the duty cycle, up to maximum speed at a duty cycle
of 90%. If the duty cycle is less than 3% or more than 90%, the cooling fan ECU interprets the signal as an open or
short circuit and runs the cooling fans at maximum speed to ensure the engine and gearbox do not overheat.
The speed of the cooling fans varies between a minimum of 750 rev/min, at 6 volts and a maximum of 4000 rev/min
at nominal battery voltage. To reduce the noise from the cooling fans they are driven at slightly different speeds,
except when running at minimum and maximum speeds. Stepped speed changes occur at 1500 rev/min (RH cooling
fan), 1450 and 2600 rev/min (LH cooling fan) to improve refinement.
between 3 and 9% the cooling fans are off. When the duty cycle goes above 9% the cooling fans come on at minimum
speed, then increase in speed, in proportion to the increase in the duty cycle, up to maximum speed at a duty cycle
of 90%. If the duty cycle is less than 3% or more than 90%, the cooling fan ECU interprets the signal as an open or
short circuit and runs the cooling fans at maximum speed to ensure the engine and gearbox do not overheat.
The speed of the cooling fans varies between a minimum of 750 rev/min, at 6 volts and a maximum of 4000 rev/min
at nominal battery voltage. To reduce the noise from the cooling fans they are driven at slightly different speeds,
except when running at minimum and maximum speeds. Stepped speed changes occur at 1500 rev/min (RH cooling
fan), 1450 and 2600 rev/min (LH cooling fan) to improve refinement.
Control Inputs
While the engine is running, the ECM adjusts the speed of the cooling fans in response to inputs from:
While the engine is running, the ECM adjusts the speed of the cooling fans in response to inputs from:
The thermostat monitoring sensor, for engine cooling. The fans come on at minimum speed if the coolant temperature goes above 90°C (194°F), and progressively increase to maximum speed at a coolant temperature of 102 °C (216°F).
The A/C system, via the instrument pack and the CAN bus, for refrigerant system cooling.
The EAT ECU, via the CAN bus, for gearbox cooling.
If there is a conflict between requested cooling fan speeds from the different inputs, the ECM adopts the highest
requested speed. As part of the power down routine, when the ignition is switched off, if the ambient air temperature is more than 15
°C (59°F) the ECM samples the coolant temperature using the input from the Engine Coolant Temperature (ECT) sensor.
If the coolant temperature is more than 106 °C (223°F), the ECM signals for the cooling fans to come on. The speed of the cooling fans is in proportion to the coolant temperature, from minimum speed at >106 °C (>223°F) to maximum speed at 115 °C (239°F). The cooling fans are switched off after 5 minutes or when the coolant temperature decreases to 106°C (223°F), whichever occurs first.
Motor Protection
The cooling fan ECU monitors the speed of the cooling fans, from the current draw of the motors, and incorporates
strategies to protect the motors from electrical overload if the fans are seized or heavily loaded (e.g. by debris or
during wading).
When the duty cycle of the PWM signal indicates the cooling fans should be switched on, the cooling fan ECU initially
outputs 2.5 volts to the motors to produce a 'soft' start. When the cooling fan ECU detects the motors are running
satisfactorily, it then increases the outputs to the appropriate voltages for the required cooling fan speeds. If a motor
fails to start within 3 seconds, the cooling fan ECU switches off the output to the affected motor, waits for 5 seconds
and then tries another soft start. If the second soft start fails, after a further wait of 5 seconds the cooling fan ECU
outputs 6 volts to the motor in an attempt to get it started. If the motor starts, the cooling fan ECU then increases the
output to the appropriate voltage for the required cooling fan speed. If the motor fails to start within 4 seconds, the
cooling fan ECU switches the output off, then, provided the cooling fans are still requested on, periodically invokes
the start routine in an attempt to get the motor running.
and then tries another soft start. If the second soft start fails, after a further wait of 5 seconds the cooling fan ECU
outputs 6 volts to the motor in an attempt to get it started. If the motor starts, the cooling fan ECU then increases the
output to the appropriate voltage for the required cooling fan speed. If the motor fails to start within 4 seconds, the
cooling fan ECU switches the output off, then, provided the cooling fans are still requested on, periodically invokes
the start routine in an attempt to get the motor running.
If a cooling fan is already running and then seizes or becomes heavily loaded, the cooling fan ECU switches off the
output to the affected motor, then periodically invokes the start routine, while the cooling fans are still requested on,
in an attempt to get the motor running again.
When one of the cooling fans is not running, the cooling fan ECU runs the other cooling fan at maximum speed.
When I get a shop manual on the LR2 I can post more accurate info, rather than the generic stuff above. Here is a sheet from the Freelander manual that shows the module and fans.
Last edited by Savannah Buzz; 11-05-2012 at 07:22 AM.
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