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2006-2009 Range Rover MkIII / L322
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Discussion Starter #1
L322 2007 Range 4.4 N/A.. NO HEAT, Boiling Coolant out of expansion tank

Hello All,
I have a 2007 Range rover 4.4 that has recently started with overheating issue. For starters, when I accelerated to obtain highway speeds (70mph) the coolant hose (with quick connect) in the rear of motor to the left of I another quick connect hose, broke lose. I immediately lost heat. Shortly after it overheated. I pulled over and put the hose back on and limped the Rangey home with the expansion tank cap off. I was able to get it home approx. 35mph with the ET cap off with no overheating issues. Once I tighten the cap pressure builds up and begins to overheat. I replaced what coolant was lost and haven't lost anymore. Ran some tests when I got it home. Upon start up and warm up and idle, there are no overheating issues. There is no heat coming from vents. I monitored the coolant temp via OBDII and takes about 10-15 mins to reach 190-200F. The gauge does not read any overheating though. I ran the truck with ET cap on and it quickly overheated through OBDII, but not truck gauge (ECT sensor?)
All in all I'm thinking the thermostat is bad and the ECT sensor has failed since gauge isn't overheating but OBDII temps reached 230F. Is there anything else I should check while replacing these two items?
 

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2006-2009 Range Rover MkIII / L322
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4 Posts
Discussion Starter #2
Re: L322 2007 Range 4.4 N/A.. NO HEAT, Boiling Coolant out of expansion tank

I also should mention when I bled the coolant system. Ran vehicle to warm up with bleeder screw open and heat on max settings. It continues to blow cold air. coolant was flowing steadily out of the bleeder on ET. After about 10 min the fan began to pick up speed (it was blowing faster than I ever noticed). Blew so hard all the coolant coming out of ET bleeder was being blown all over the engine. I immediately cut off Range and let cool. The fan cuts on when truck is started and it never cut off, even when I stopped heater. Any help is greatly appreciated. Thanks in advance.
 

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2006-2009 Range Rover MkIII / L322
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4 Posts
Discussion Starter #3
Re: L322 2007 Range 4.4 N/A.. NO HEAT, Boiling Coolant out of expansion tank

Update to my issue, to whom it may concern. Replaced the thermostat and bled the system. A ton of air was in the lines, I'm assuming from when the hose blew off. Which by the way was the feed hose to the Aux. pre heater. Everything is in working order to date.
 

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2006-2009 Range Rover MkIII / L322
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Got the same problem - Car is overheated by no Warning Lights. I will change the Thermostat and maybe the Exp. Tank Sensor also.
 

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DMAN, lack of heat paired with overheating almost always means lack of coolant. Do a proper bleed of the system to purge the air from your system before you start throwing parts at it.
 

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2002-2005 Range Rover MkIII / L322
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37 Posts
Hello All,
I have a 2007 Range rover 4.4 that has recently started with overheating issue. For starters, when I accelerated to obtain highway speeds (70mph) the coolant hose (with quick connect) in the rear of motor to the left of I another quick connect hose, broke lose. I immediately lost heat. Shortly after it overheated. I pulled over and put the hose back on and limped the Rangey home with the expansion tank cap off. I was able to get it home approx. 35mph with the ET cap off with no overheating issues. Once I tighten the cap pressure builds up and begins to overheat. I replaced what coolant was lost and haven't lost anymore. Ran some tests when I got it home. Upon start up and warm up and idle, there are no overheating issues. There is no heat coming from vents. I monitored the coolant temp via OBDII and takes about 10-15 mins to reach 190-200F. The gauge does not read any overheating though. I ran the truck with ET cap on and it quickly overheated through OBDII, but not truck gauge (ECT sensor?)
All in all I'm thinking the thermostat is bad and the ECT sensor has failed since gauge isn't overheating but OBDII temps reached 230F. Is there anything else I should check while replacing these two items?
I'm not sure what the normal operating temperature is for AJ V8 engines but in my 05 the normal coolant temp is around 110*C(230*F)
 
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