random temperature reading
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random temperature reading
I have a 98 Expedition 4.6 that has problems. Here's a history of whats been done to it recently.
New water pump
New radiator
New radiator hoses
New thermostat
New coolant temperature sensors
New passenger side valve gasket
New spark plugs and wires
New ignition coil packs
New belt
New oil change
All of this was done by myself and my brother and within the past month. Now that you have a history of the work here is the problem I need help with: my temperature gauge keeps shooting up to H then back to the midway mark throughout driving without turning the engine off or burping the reservoire. When i do pull over and check the engine there are absolutely no signs of overheating.
Guys, I need help. Ive had a compression test to tell me if I have a bad head gasket and the results came back negative.
Any ideas why she's randomly reading hot then normal all in a matter of seconds???
New water pump
New radiator
New radiator hoses
New thermostat
New coolant temperature sensors
New passenger side valve gasket
New spark plugs and wires
New ignition coil packs
New belt
New oil change
All of this was done by myself and my brother and within the past month. Now that you have a history of the work here is the problem I need help with: my temperature gauge keeps shooting up to H then back to the midway mark throughout driving without turning the engine off or burping the reservoire. When i do pull over and check the engine there are absolutely no signs of overheating.
Guys, I need help. Ive had a compression test to tell me if I have a bad head gasket and the results came back negative.
Any ideas why she's randomly reading hot then normal all in a matter of seconds???
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I'll double check it today then. Ive installed many thermostats though and Im pretty sure its opening and closing properly and was installed properly.
Could it be the CHT sensor? Where is exactly is it located?
Could it be the CHT sensor? Where is exactly is it located?
Fleet Owner
Joined: Apr 2008
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From: 0,0,1
I doubt it, but if you want to check it, look for it above the #5 cylinder, just above and to the right of the water pump.
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still having the overheating issue
So i dropped this project for a while to help a friend rebuild his 96mustang gt. Back to the big slow suv now, it's still overheating.
I replaced the CHT sensor and installed another thermostat but no help. However, even in this Texas heat it wont overheat as long as im under 1800 rpm. The second i get above that threshhold it starts to gradually rise up.
Also, dont know if i mentioned this but i have a bad catalytic converter, bank 2. Could that be causing back pressure resulting in the overheating?
I replaced the CHT sensor and installed another thermostat but no help. However, even in this Texas heat it wont overheat as long as im under 1800 rpm. The second i get above that threshhold it starts to gradually rise up.
Also, dont know if i mentioned this but i have a bad catalytic converter, bank 2. Could that be causing back pressure resulting in the overheating?
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forgot to mention
Its actually overheating now, not just bluffing on the temperature gauge. No more gauge shooting straight up and down anymore (maybe the CHT replacement worked?). Its actually overheating.
Logistics Pro
Joined: Mar 2005
Posts: 4,698
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From: Mexico, Missouri
From my research and reading, if the Cat has failed, there's a reason unless its just at its end of life.
If the material inside is causing a backpressure problem, then it's going to cause engine problems as well. I would think that if it's clogged, you would notice bogging down problems when driving or lack of power. Best thing to do is drill holes in it or cut it and punch it out and then see id your overheat problem clears up.
Other than that, be absolutely positive that it's overheating with IR thermometer if any doubt.
Catalytic converters fail from excess fuel in exhaust, coolant intrusion, excessive lean fuel conditions or using engine oil high in ZDDP over prolonged periods of time, usually failing within the 100k mile mark.
If the material inside is causing a backpressure problem, then it's going to cause engine problems as well. I would think that if it's clogged, you would notice bogging down problems when driving or lack of power. Best thing to do is drill holes in it or cut it and punch it out and then see id your overheat problem clears up.
Other than that, be absolutely positive that it's overheating with IR thermometer if any doubt.
Catalytic converters fail from excess fuel in exhaust, coolant intrusion, excessive lean fuel conditions or using engine oil high in ZDDP over prolonged periods of time, usually failing within the 100k mile mark.
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