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Atl Red
Anonymous Poster
quensdad@hotmail.com
Jun 24, 2009, 9:52 AM
Post #1 of 8
(4637 views)
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car running at high temp
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My '95 Olds Aurora 4.0 w/ 245k miles is running 20 - 30 degrees above normal running temp. Any ideas what can cause this.
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Hammer Time
Ultimate Carjunky
/ Moderator
Jun 24, 2009, 11:13 PM
Post #2 of 8
(4625 views)
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Re: car running at high temp
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2 questions
What are you calling normal temp?
Is this happening in slow traffic or stopped situations?
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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.
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Guest
Anonymous Poster
Jun 25, 2009, 2:41 AM
Post #3 of 8
(4619 views)
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Re: car running at high temp
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180 degrees normal now running around 210 degrees. This is now the all time temp., may move up in slow traffic.
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Hammer Time
Ultimate Carjunky
/ Moderator
Jun 25, 2009, 2:48 AM
Post #4 of 8
(4617 views)
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Re: car running at high temp
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That's where you are wrong. 180 degrees is not normal. The car uses a 195 thermostat but the cooling fan isn't programmed to come on until over 225 so anything up to 230 degrees can be considered normal as long as it never goes higher.
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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.
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Guest
Anonymous Poster
Jun 25, 2009, 10:26 AM
Post #5 of 8
(4613 views)
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Re: car running at high temp
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I,ve had car for 5yrs always ran around 180 degrees what would change that in last 3 mos. Water pump & thermostst - new, fans - working even tried water wetter/cooler still no change
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Hammer Time
Ultimate Carjunky
/ Moderator
Jun 25, 2009, 10:28 AM
Post #6 of 8
(4610 views)
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Re: car running at high temp
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The car is not supposed to run at 180 degrees. That will actually cause a lot of problems. It has to run hotter.
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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.
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Hammer Time
Ultimate Carjunky
/ Moderator
Jun 25, 2009, 10:40 AM
Post #7 of 8
(4605 views)
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Re: car running at high temp
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Here is how the cooling fan system works straight from the manual
The electric cooling fan(s) are used to cool engine coolant flowing through the radiator. They are also used to cool the refrigerant (R134a) flowing through the A/C condenser.
OPERATION
The electric cooling fans are controlled by the PCM. The PCM controls the ground path for the three cooling fan relays. The relays are used to control the high current flow to power the cooling fan motors. Both fans operate together. When minimum cooling is required, the PCM energizes the low speed cooling fan relay #1, and both fans operate at low speed since the fans are connected in series through the series/parallel cooling fan relay #2. When maximum cooling is required, the PCM energizes all three cooling fan relays. The left hand coolant fan is still power through the low speed cooling fan relay #1, but is now grounded through the series/parallel cooling fan relay #2 and operates at high speed. The right hand coolant fan is powered directly through the high speed cooling fan relay #3 and also operates at high speed.
Low Speed Fans
The cooling fans are controlled by the PCM based on inputs from the A/C system, Engine Coolant Temperature (ECT) sensor and Vehicle Speed Sensor (VSS) .
The PCM will command low speed fans "ON" when Engine Coolant Temperature (ECT) is above 106°C (223°F). The PCM will turn the fans "OFF" when the temperature drops about 3°C (5°F). The minimum "ON" time for low speed fans is 50 seconds.
High Speed Fans
The PCM will command high speed fans "ON" when any of the following conditions exist at idle.
- Certain Diagnostic Trouble Codes (DTCs) set.
- ECT above 110°C (230°F).
- A/C head pressure above 248 psi.
If the high speed fans were turned "ON" by the ECT, the PCM will switch the fans back to low speed when the temperature drops about 3°C (5°F). Minimum "ON" time for HI speed fans is 30 seconds.
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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.
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Sidom
Veteran
/ Moderator
Jun 25, 2009, 4:54 PM
Post #8 of 8
(4599 views)
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Re: car running at high temp
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The only thing I'm curious about is... How are you taking your measurement? If you are going by the gauge on the dash, that isn't the best way. While it's good for calling attention to an overheat condition it's not the best method for slight variations.
The temp sensor is a thermistor and while it "could" show a slight change the more common problems I've seen with those is either the resistance valve of the senor or circuit changes which the end result is a false reading on the dash..
For slight rise changes you have to verify there is a change by comparing the what the dash & the computer are reporting & also take reading with a digital thermometer. Then you know if it's electrical or that there is in fact a cooling problem.....
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