Very low temp.. especially while freeway cruising
10-19-2011, 03:15 AM
#1
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Very low temp.. especially while freeway cruising
I know this sounds odd to be concerned with, but my car really seems to run cooler than it should.
When driving around town and sitting at stoplights for short periods, the needle on the gauge usually sits about half-way between the second mark and the center point between the 2nd and 3rd marks. If I let it idle for a good while in the driveway, it will eventually reach the half-way point and occasionally a bit above before the fans kick on. But what seems really concerning is that when I'm cruising on the freeway, the needle just hovers around the 2nd mark... it never gets more than a needle-width above it, and is either covering it or at least touching it most of the time. That's not normal, is it?
It's been a few years, but I really seem to remember the gauge on my old NA sitting pretty much perfectly in the middle of the gauge almost all of the time.
What do you guys think?
TIA!
When driving around town and sitting at stoplights for short periods, the needle on the gauge usually sits about half-way between the second mark and the center point between the 2nd and 3rd marks. If I let it idle for a good while in the driveway, it will eventually reach the half-way point and occasionally a bit above before the fans kick on. But what seems really concerning is that when I'm cruising on the freeway, the needle just hovers around the 2nd mark... it never gets more than a needle-width above it, and is either covering it or at least touching it most of the time. That's not normal, is it?
It's been a few years, but I really seem to remember the gauge on my old NA sitting pretty much perfectly in the middle of the gauge almost all of the time.
What do you guys think?
TIA!
10-19-2011, 03:43 AM
#2
Burning Brakes
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You're not driving an NA anymore. My 89 does the same thing, providing I'm not flogging it, it's getting colder out, and I have definitely seen the needle be down a bit from the normal spot.
It sounds like your fans are working as designed, and the needed does seem to get up where it should be in traffic. Oil pressure is good? Oil weight reasonable for the weather? I believe you are up on all your grounds, etc.
Worst case, whip out your laser thermometer (Amazon) and see what the head is... =)
It sounds like your fans are working as designed, and the needed does seem to get up where it should be in traffic. Oil pressure is good? Oil weight reasonable for the weather? I believe you are up on all your grounds, etc.
Worst case, whip out your laser thermometer (Amazon) and see what the head is... =)
10-19-2011, 07:48 AM
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The first white line (I don’t count any marks that are not inside the usual gauge range!) is 80c – that is where your thermostat should open. On a car that has a cooling system operating in very good condition the needle should stay at this position as long as there is air moving over the radiator (driving over 25mph). This is true even for highly modified engines.
If you are driving slow or at idle the temps will go up until the fan(s) come on. The first fan comes on at about the mid point There is some difference here because the gauge is measuring head temps and the fan switch is using radiator temps). If the gauge gets top the upper white mark both fans should be on at full speed. This is nto that uncommon if you have been driving at speed and then stop in traffic for a while.
If it goes over the second white line then you really need to take a look at your cooling system – radiator, water pump and thermostat. Something isn’t working well!
If you are driving slow or at idle the temps will go up until the fan(s) come on. The first fan comes on at about the mid point There is some difference here because the gauge is measuring head temps and the fan switch is using radiator temps). If the gauge gets top the upper white mark both fans should be on at full speed. This is nto that uncommon if you have been driving at speed and then stop in traffic for a while.
If it goes over the second white line then you really need to take a look at your cooling system – radiator, water pump and thermostat. Something isn’t working well!
10-19-2011, 08:22 AM
#6
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Good information! Mine typically sits between the first and second line, more towards to bottom/first line while cruising.
If sitting in traffic for a short while, it'll creep up between #2 and # 3. If sitting/idling for an extended time, it'll creep all the way to # 3.
During last winter, I rarely had any heat in the car if the outside temp was below freezing while cruising either in town or on the highway.
If sitting in traffic for a short while, it'll creep up between #2 and # 3. If sitting/idling for an extended time, it'll creep all the way to # 3.
During last winter, I rarely had any heat in the car if the outside temp was below freezing while cruising either in town or on the highway.
10-19-2011, 12:46 PM
#7
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The heat is fine... as in, it will become uncomfortably hot very quickly...
Thanks, Chris! That makes me feel better. Mine behaves pretty much exactly as you say it should then... and it never gets above the 3rd (or 2nd, if you only count marks within the operating range) mark. It just seemed low to me, but it has been chilly and if it's nothing to worry about, I'll stop worrying!
The first white line (I don’t count any marks that are not inside the usual gauge range!) is 80c – that is where your thermostat should open. On a car that has a cooling system operating in very good condition the needle should stay at this position as long as there is air moving over the radiator (driving over 25mph). This is true even for highly modified engines.
If you are driving slow or at idle the temps will go up until the fan(s) come on. The first fan comes on at about the mid point There is some difference here because the gauge is measuring head temps and the fan switch is using radiator temps). If the gauge gets top the upper white mark both fans should be on at full speed. This is nto that uncommon if you have been driving at speed and then stop in traffic for a while.
If it goes over the second white line then you really need to take a look at your cooling system – radiator, water pump and thermostat. Something isn’t working well!
If you are driving slow or at idle the temps will go up until the fan(s) come on. The first fan comes on at about the mid point There is some difference here because the gauge is measuring head temps and the fan switch is using radiator temps). If the gauge gets top the upper white mark both fans should be on at full speed. This is nto that uncommon if you have been driving at speed and then stop in traffic for a while.
If it goes over the second white line then you really need to take a look at your cooling system – radiator, water pump and thermostat. Something isn’t working well!
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10-19-2011, 12:58 PM
#8
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Did you check to see if you even have a thermostat in the car?
I have 3 951's, all with the same oem cooling system and fluids, nothing out of the ordinary. However one of them has no thermostat, and it runs extremely cool all the time. It sounds to me like your thermostat could be stuck open or you may just not have one at all...
Definitely a better problem to have then your car getting too hot!!
I have 3 951's, all with the same oem cooling system and fluids, nothing out of the ordinary. However one of them has no thermostat, and it runs extremely cool all the time. It sounds to me like your thermostat could be stuck open or you may just not have one at all...
Definitely a better problem to have then your car getting too hot!!
10-19-2011, 10:50 PM
#10
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I replaced the primary coolant t-stat with a 160 degree one soon after I bought the car and did the pump & belts. When I did my major rebuild this year, I replaced the turbo t-stat and the oil t-stat, so they are all new now. My car runs at the lower-third mark pretty much all the time unless it's really hot and I'm stuck in traffic.
10-20-2011, 12:22 AM
#11
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I replaced the primary coolant t-stat with a 160 degree one soon after I bought the car and did the pump & belts. When I did my major rebuild this year, I replaced the turbo t-stat and the oil t-stat, so they are all new now. My car runs at the lower-third mark pretty much all the time unless it's really hot and I'm stuck in traffic.
