strange coolant temperature readings. runs hotter when colder outside
09-03-2007, 08:16 PM
#1
Pro
Thread Starter
strange coolant temperature readings. runs hotter when colder outside
Hey guys,
Since there is such a weath of knowledge on here I thought I'd share an observation and see what it might mean. This is on an '83 944. Ok, I left Phoenix on Friday night and the temps were still in the 100s outside. temp guage read almost right at the middle bar, maybe a slight bit higher but when the lights are on, the gauge reads higher so I "round down" when the lights are on. I cruised at 80-85mph almost the entire trip to California. The temps most likely never dropped below 95 degrees ambient. Once I got to Cali, the temp were a bit lower. I noticed something strange. I was cruising on the 241 toll road just outside of Irvine and the outside temps were noticably cool, Id guess in the 70's somewhere but I checked the temp gauge, it was reading higher! I had to stop to pay tolls a few times and when I stopped, the temps dropped rapidly, to slightly before the middle line on the gauge. sure enough, once I started moving again (65mph) the temps climbed almost to the 3rd bar, before settling and slightly dropping but still reading hotter than it does when driving in 100+ degree heat. Does this indicate a faulty thermostat? I noticed that when I installed the thermostat that it sits "loose" in there but it won't come out. I have never seen a car run hotter when the ambient temperatures are low, then run cooler when the ambient temps are warmer. Any thoughts?
Since there is such a weath of knowledge on here I thought I'd share an observation and see what it might mean. This is on an '83 944. Ok, I left Phoenix on Friday night and the temps were still in the 100s outside. temp guage read almost right at the middle bar, maybe a slight bit higher but when the lights are on, the gauge reads higher so I "round down" when the lights are on. I cruised at 80-85mph almost the entire trip to California. The temps most likely never dropped below 95 degrees ambient. Once I got to Cali, the temp were a bit lower. I noticed something strange. I was cruising on the 241 toll road just outside of Irvine and the outside temps were noticably cool, Id guess in the 70's somewhere but I checked the temp gauge, it was reading higher! I had to stop to pay tolls a few times and when I stopped, the temps dropped rapidly, to slightly before the middle line on the gauge. sure enough, once I started moving again (65mph) the temps climbed almost to the 3rd bar, before settling and slightly dropping but still reading hotter than it does when driving in 100+ degree heat. Does this indicate a faulty thermostat? I noticed that when I installed the thermostat that it sits "loose" in there but it won't come out. I have never seen a car run hotter when the ambient temperatures are low, then run cooler when the ambient temps are warmer. Any thoughts?
09-04-2007, 06:13 AM
#4
Rennlist Member
When I had this happen to my 83 it was a stuck thermostat.
Were the fans running when you stopped at the tolls? Also, check the fan relay (it doubles as the A/C relay) and see if it's getting hot.
Were the fans running when you stopped at the tolls? Also, check the fan relay (it doubles as the A/C relay) and see if it's getting hot.
09-04-2007, 08:47 AM
#5
Rennlist Member
check to make sure both fans are running
bleed any air out of the system- air pockets will cause strange gauge readings
clean the grounds for the gauges up under the ds of the dashboard
could have a messed up thermostat but do this stuff first.
bleed any air out of the system- air pockets will cause strange gauge readings
clean the grounds for the gauges up under the ds of the dashboard
could have a messed up thermostat but do this stuff first.
09-04-2007, 04:22 PM
#6
Pro
Thread Starter
yea, I also have a low temp fan switch so pretty much whenever I drive it the fans run. I might change it back to stock. Im thinking its thermostat related..I mean, when the ambient air is cooler, the car ran hotter!
