Odd temperatures
Odd temperatures
However, when driven at ambient temperatures below 45f the engine always runs hot in the 95-100c range no matter how easy or hard its driven.
Its done this as long as I've owned it. It has a new Behr Thermostat. All the air has been purged. I've flushed out all the rust and debris from the previous owners.
My best guess is the combination of cold water from the radiator cooling the thermostat pill and the lack of a cabin heater to reject heat is enough to raise the regulated temperature. Kind of like putting the house thermostat too close to an output vent.
Any other ideas?
ForcedInduction
03-19-2011, 06:29 AM
#1
When my 300D is driven on warm/hot days the operating temperature is a solid 80-85c no matter how hot it gets outside or even in traffic.
However, when driven at ambient temperatures below 45f the engine always runs hot in the 95-100c range no matter how easy or hard its driven.
Its done this as long as I've owned it. It has a new Behr Thermostat. All the air has been purged. I've flushed out all the rust and debris from the previous owners.
My best guess is the combination of cold water from the radiator cooling the thermostat pill and the lack of a cabin heater to reject heat is enough to raise the regulated temperature. Kind of like putting the house thermostat too close to an output vent.
Any other ideas?
Iirc the line comes back somewheres near the drivers side rear, so maybe with the reduced flow from the t-stat trying to maintain block temp, you're getting a stagnant pocket of coolant back there, and with the temp sensor being back there, it's picking it up?
I'd get out an IR thermo gun, and check.
This assumes that passage was blocked off as part of the heater core removal, and not just looped. Then again, it could have been engineered to use the drop in temp across the heater core as well..
My best guess for the day.
1990 Power Ram 50 V6 SOHC 24V 6g72
I can be wrong, don't take everything I say as verbatim, please fact-check first.
My posts are my personal opinions and thoughts, unless otherwise noted.
Maybe the loop-back route that the heater core water takes is required for the system to operate properly?
Iirc the line comes back somewheres near the drivers side rear, so maybe with the reduced flow from the t-stat trying to maintain block temp, you're getting a stagnant pocket of coolant back there, and with the temp sensor being back there, it's picking it up?
I'd get out an IR thermo gun, and check.
This assumes that passage was blocked off as part of the heater core removal, and not just looped. Then again, it could have been engineered to use the drop in temp across the heater core as well..
My best guess for the day.
1990 Power Ram 50 V6 SOHC 24V 6g72
I can be wrong, don't take everything I say as verbatim, please fact-check first.
My posts are my personal opinions and thoughts, unless otherwise noted.
1981 300SD 230k miles "Gently Modified" Daily Driver
1999 F-250 7.3L Power Stroke 150k miles "The Usual Mods" Tow Rig
1981 300SD 190k miles "Heavily Modified"
GONE
DrewGerhan
03-20-2011, 09:14 PM #3I noticed that in my car earlier this winter as well. It didn't happen everytime but everynow and again when it was "chilly", not cold, it would run a little hotter than 80*C. Never gave it much though as it runs at 80*C now that it has warmed up.
1981 300SD 230k miles "Gently Modified" Daily Driver
1999 F-250 7.3L Power Stroke 150k miles "The Usual Mods" Tow Rig
1981 300SD 190k miles "Heavily Modified"
GONE
Other than that, on steep hills (any high load, low speed condition) in cold weather, the engine temp shoots up and stays there. However, in warm weather, the temps stay more stable.
Personally, I always thought it was a matter of the ACC robbing the head of coolant flow. This would lead to the closing of the bypass valve on the t-stat since the block will heat up and demand more flow through the radiator.
ps - nice job on the ASE cert.
totaldisaster
03-27-2011, 04:12 PM #5I have also experienced something similar. Except that the higher engine temps only happen when I have my heat on.
Other than that, on steep hills (any high load, low speed condition) in cold weather, the engine temp shoots up and stays there. However, in warm weather, the temps stay more stable.
Personally, I always thought it was a matter of the ACC robbing the head of coolant flow. This would lead to the closing of the bypass valve on the t-stat since the block will heat up and demand more flow through the radiator.
ps - nice job on the ASE cert.
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