help with overheating
#21
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badicedog (10-25-2023)
#23
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@badicedog I think you need a multi meter from here. imo you need to check voltage at the fan (SAFELY), or possibly start at the ECU. You will have constant battery power at the fan as I mention above. Then you will have switched power, also noted above. I doubt the fuse is the issue as it controls other things as @McJag noted. Also as he states, check the ground points.
In the case of our Jaguars, the Coolant Temp sensor measure the coolant temp> sends a signal the the ECM> ECM sends a pulse width modulated signal to the fan telling it how fast to go.
So for me, the first and simplest test is voltage output at the coolant temp sensor. It's on top of the engine. It's simply a thermistor so once enough resistance build, it sends a signal to the ECU. The hotter the coolant, the higher resistance. I'm not a parts swapper but these are cheap. Using the infrared thermometer, you'll know when the fan should start. Check and confirm a signal is coming out of the coolant temp sensor. Then I would check the output @ fan. PIA I know. As mentioned earlier, less than 9 volts...
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badicedog (10-25-2023)
#24
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If it is the 4.2 N/A v8.
Have you checked the plastic thermostat Housing, where the thermostat sits?
There may be a large chip out of the housing seat where the thermostat is mounted, causing the cooling water to bypass the radiator and recirculation of the coolant, through the pump thereby causing over heating.
Have you checked the plastic thermostat Housing, where the thermostat sits?
There may be a large chip out of the housing seat where the thermostat is mounted, causing the cooling water to bypass the radiator and recirculation of the coolant, through the pump thereby causing over heating.
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badicedog (10-25-2023)
#25
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@McJag this appears to be the elec diagram for 2010 onward. The 80 amp Midi is correct, which is battery power and located in the engine bay power distribution box It's Brown/ Green and goes directly to the fan. The other fuse is F14 (not F31) which is ignition powered and also located in the engine bay distribution box. OP said fuses check out but sometimes use replacing the fuse is worth the effort.
@badicedog I think you need a multi meter from here. imo you need to check voltage at the fan (SAFELY), or possibly start at the ECU. You will have constant battery power at the fan as I mention above. Then you will have switched power, also noted above. I doubt the fuse is the issue as it controls other things as @McJag noted. Also as he states, check the ground points.
In the case of our Jaguars, the Coolant Temp sensor measure the coolant temp> sends a signal the the ECM> ECM sends a pulse width modulated signal to the fan telling it how fast to go.
So for me, the first and simplest test is voltage output at the coolant temp sensor. It's on top of the engine. It's simply a thermistor so once enough resistance build, it sends a signal to the ECU. The hotter the coolant, the higher resistance. I'm not a parts swapper but these are cheap. Using the infrared thermometer, you'll know when the fan should start. Check and confirm a signal is coming out of the coolant temp sensor. Then I would check the output @ fan. PIA I know. As mentioned earlier, less than 9 volts...
@badicedog I think you need a multi meter from here. imo you need to check voltage at the fan (SAFELY), or possibly start at the ECU. You will have constant battery power at the fan as I mention above. Then you will have switched power, also noted above. I doubt the fuse is the issue as it controls other things as @McJag noted. Also as he states, check the ground points.
In the case of our Jaguars, the Coolant Temp sensor measure the coolant temp> sends a signal the the ECM> ECM sends a pulse width modulated signal to the fan telling it how fast to go.
So for me, the first and simplest test is voltage output at the coolant temp sensor. It's on top of the engine. It's simply a thermistor so once enough resistance build, it sends a signal to the ECU. The hotter the coolant, the higher resistance. I'm not a parts swapper but these are cheap. Using the infrared thermometer, you'll know when the fan should start. Check and confirm a signal is coming out of the coolant temp sensor. Then I would check the output @ fan. PIA I know. As mentioned earlier, less than 9 volts...
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badicedog (10-25-2023)
#26
#27
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Two month ago, on my 2007, same 50k miles, there was a coolant loss. Refilled it. Loss again and very little hose pressure.
The leak was under the plastic manifold cover. A small hose from the cabin side of the the coolant tank has a straight connector under the manifold cover. The connector had fallen apart!!! Replaced it with 3/8" copper pipe. Pressure returned and it kept the new coolant.
The leak was under the plastic manifold cover. A small hose from the cabin side of the the coolant tank has a straight connector under the manifold cover. The connector had fallen apart!!! Replaced it with 3/8" copper pipe. Pressure returned and it kept the new coolant.
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Bill400 (11-29-2023)
#28
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Sean W (10-25-2023)
#29
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Two month ago, on my 2007, same 50k miles, there was a coolant loss. Refilled it. Loss again and very little hose pressure.
The leak was under the plastic manifold cover. A small hose from the cabin side of the the coolant tank has a straight connector under the manifold cover. The connector had fallen apart!!! Replaced it with 3/8" copper pipe. Pressure returned and it kept the new coolant.
The leak was under the plastic manifold cover. A small hose from the cabin side of the the coolant tank has a straight connector under the manifold cover. The connector had fallen apart!!! Replaced it with 3/8" copper pipe. Pressure returned and it kept the new coolant.
#30
#31
#32
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What part of the intake is troubling you? It's pretty straightforward. Did you take the bolts out of the mounts at the front of the valve cover area?
#33
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there is a small hose that leads to the valve cover and attaches to the cool air intake asssembly also since mine Jag is a NA and not Supercharged with dual intakes, there is hose/duct that attaches on the passender side that runs into the firewall. ill snap a pic for referrence
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Cee Jay (10-25-2023)
#34
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Hi, guys... I been busy with life and work so the repair has taken a back seat. I did check the thermostat hoses and both are both with similar temps. I found a broken vacuum line that leads to the radiator fan. Im not sure if this is even related to the fan not turning on or not. I will post some pics
#35
#36
#38
Join Date: Aug 2012
Location: Mechanicsville, Virginia, USA
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Yes he has the 4.2, Fan should spin freely. Is that happening? is it obstructed?
I know you mentioned thermostat but least likely the problem imo and your codes confirm that. Easily checked without disassembly. Point an infrared thermometer to the hoses on either side of it, once the stat reaches operating temp, the hose temps will be the same on output and input.
I know you mentioned thermostat but least likely the problem imo and your codes confirm that. Easily checked without disassembly. Point an infrared thermometer to the hoses on either side of it, once the stat reaches operating temp, the hose temps will be the same on output and input.
Performance requirements and operating conditions | SKF
Easy to check, Should spin freely and coast when pushed.
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