Low Coolant (but only sometimes)
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Joined: Jun 2001
Posts: 509
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From: Edmonds WA
Low Coolant (but only sometimes)
I've got an interesting situation going on... it seems almost daily, the Low Coolant light comes on, but I've packed the cooling system several times to try and "burp" it and can't seem to get past the problem. It doesn't overheat or anything... it runs at normal temps.
I've been carrrying a bottle of water with me and I drive a couple of miles in the morning before the thermostat opens; if the Low Coolant light comes on, I pull over and open the cap, but it's full; I run up the engine, but I can usually only add a few ounces of water. If I don't do anything, the light will go out in a couple of minutes and it usually doesn't come on the rest of the day (sometimes, it has come on during freeway cruise). The overflow tank is half-full and hasn't changed over the past few weeks.
The interesting thing is that the light seems to come on when the drive train is unloaded (that is, coasting with foot off the gas). I keep thinking I've got air trapped in the system and somehow it makes its way to the radiator after the t-stat opens, but then when I pull over and check it, the radiator is full
I believe the sensor and Low Coolant light are working properly.
Any ideas on what's going on?
Thanks!
I've been carrrying a bottle of water with me and I drive a couple of miles in the morning before the thermostat opens; if the Low Coolant light comes on, I pull over and open the cap, but it's full; I run up the engine, but I can usually only add a few ounces of water. If I don't do anything, the light will go out in a couple of minutes and it usually doesn't come on the rest of the day (sometimes, it has come on during freeway cruise). The overflow tank is half-full and hasn't changed over the past few weeks.
The interesting thing is that the light seems to come on when the drive train is unloaded (that is, coasting with foot off the gas). I keep thinking I've got air trapped in the system and somehow it makes its way to the radiator after the t-stat opens, but then when I pull over and check it, the radiator is full
I believe the sensor and Low Coolant light are working properly.
Any ideas on what's going on?
Thanks!
Burning Brakes
Joined: Dec 2002
Posts: 1,199
Likes: 4
From: Cairns Australia
Speaking from my vast 18months vette experience (OK I'm still a newbie) - first thing is to replace the radiator cap - I had a boil over 2 months after fitting a new cap because radiator was clogged. I didn't realise that one boilover can kill a new radiator cap.
2nd, my local radiator shop fitted a 'hi flow' 180 t'stat because I was running too cool with the 160 t'stat and new radiator - they drilled holes in the T'stat and say they always do - this helps to burp the system and remove air.
3rd - the sensor in the radiator may be going faulty.
Some people park on a slope to help burp the rad, but I've always managed to fix that annoying 'low coolant light' by topping up just after the t'stat opens - as you are doing.
Hope this helps.
S'nut
2nd, my local radiator shop fitted a 'hi flow' 180 t'stat because I was running too cool with the 160 t'stat and new radiator - they drilled holes in the T'stat and say they always do - this helps to burp the system and remove air.
3rd - the sensor in the radiator may be going faulty.
Some people park on a slope to help burp the rad, but I've always managed to fix that annoying 'low coolant light' by topping up just after the t'stat opens - as you are doing.
Hope this helps.
S'nut
Thread Starter
Pro
Joined: Jun 2001
Posts: 509
Likes: 5
From: Edmonds WA
Originally Posted by Stingraynut
...my local radiator shop fitted a 'hi flow' 180 t'stat because I was running too cool with the 160 t'stat and new radiator - they drilled holes in the T'stat and say they always do - this helps to burp the system and remove air.
Hmmm... I'm running a 160 t-stat, as well. But, I'm confused why the shop thinks you're running too cool at 160?
3rd - the sensor in the radiator may be going faulty.
Thanks!
Burning Brakes
Joined: Dec 2002
Posts: 1,199
Likes: 4
From: Cairns Australia
Quote "Quote:
3rd - the sensor in the radiator may be going faulty.
I've considered this, too... but I wish I could tell, for sure... I've learned that replacing parts as a diagnostic approach usually just proves expensive."
I know what you mean, but the sensor can be checked with a multimeter - sorry I don"t know the values but they'll be in the manual or some guru here will know.
Re my low running temps - I live in the mid tropcis so even in winter I often use the aircon in the middle of the day - it's humid and apart from about 2 weeks, warm.
Once I had the radiator cleaned inside I started to see 165F after 30 mins running. I thought that was too cool so decided to get the shop to fit a 180 T'stat. Since then my lowest temp is 185F - and on a run, while it's winter here, it will stay there - soon goes above 212F in traffic though, which is when I flip the manual fan switch.
In summer it will be running much hotter, but once the t'stat is open - it's open and has no effect on the temp - especially a 'Hi flow' t'stat and also with holes drilled in it !
I read recently a post saying that it's only partially open at 180degrees - fair enough, but I reckon by 212 it's as open as it gets.
S'nut
3rd - the sensor in the radiator may be going faulty.
I've considered this, too... but I wish I could tell, for sure... I've learned that replacing parts as a diagnostic approach usually just proves expensive."
I know what you mean, but the sensor can be checked with a multimeter - sorry I don"t know the values but they'll be in the manual or some guru here will know.
Re my low running temps - I live in the mid tropcis so even in winter I often use the aircon in the middle of the day - it's humid and apart from about 2 weeks, warm.
Once I had the radiator cleaned inside I started to see 165F after 30 mins running. I thought that was too cool so decided to get the shop to fit a 180 T'stat. Since then my lowest temp is 185F - and on a run, while it's winter here, it will stay there - soon goes above 212F in traffic though, which is when I flip the manual fan switch.
In summer it will be running much hotter, but once the t'stat is open - it's open and has no effect on the temp - especially a 'Hi flow' t'stat and also with holes drilled in it !
I read recently a post saying that it's only partially open at 180degrees - fair enough, but I reckon by 212 it's as open as it gets.
S'nut
