thats what i always watch :p:
Low Coolant light again!
Thread Starter
Racer
Joined: Aug 2001
Posts: 416
Likes: 0
From: Astoria OR
Low Coolant light again!
I had this problem a few months ago. I idled the car up to about 2 grand as I put more coolant in and it was fine for awile. The light came back on 2 days ago. I filled it using the same method but the light is still on. Im going to add more when it cools down. Ant tips or suggestions to get this light off?
Le Mans Master
Joined: Jul 2002
Posts: 5,818
Likes: 2
From: Alive and well in Burlington NC
Re: Low Coolant light again! (Tim89)
Hate to ask the obvious but have you checked for leaks. My 91 did the exact same thing and I had noticed a small puddle of coolant every now and then. Turned out to be an intake manifold gasket leak. Replaced the gasket and all is well.
Melting Slicks
Joined: Apr 2002
Posts: 2,631
Likes: 2
From: Clever, MO aka SOMO
Re: Low Coolant light again! (Tim89)
Yeah, check for some little leaks on the engine. Most of those little leaks evaporate before they hit the pavement, due to the heat of the engine. Make sure you have the correct level in your holding tank also. My '88 lites up once in awhile also, but the engine never runs hot so I haven't worried too much about the occasional Low Coolant lite.
Good Luck!
Good Luck!
Le Mans Master
Joined: Jul 2001
Posts: 8,183
Likes: 3
From: Santa Maria, CA
Re: Low Coolant light again! (Tim89)
I get that light alot. I packed the shiat out of the system too. burping and revving, heater on, all the stuff. I dunno, think it's just a shiatty sensor. I keep thinking it reads the ph level of the coolant also :confused: damn light always comes and goes. :rolleyes: :chevy :rolleyes:
Le Mans Master
Joined: Mar 2001
Posts: 9,464
Likes: 1
From: Modesto CA
Re: Low Coolant light again! (89 Paul in Cal)
It's eeerie for me..it'll come on when I'm driving home from my gf's house at like 2am. Only on the freeway, doing 70mph steady, then when I get off the freeway the light goes off and won't come back on for another few weeks. I dunno...it's just an idiot light anyway...coolant temperature is the best way to watch for low coolant. IMHO
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Racer
Joined: Jul 2001
Posts: 253
Likes: 0
Re: Low Coolant light again! (Tim89)
This is going to sound dumb, but I had the same problem and did a coolant change - by accident... How do you do a coolant change by accident? :confused: By trying to force pack the radiator - you know - revving up to 2K RPM and then top off the rad???
Well, mine sprayed out and almost gave me a hot bath. :mad: :cuss: After that happened twice in a row, I ended up just draining the rest and refill, then drive around and re-check / top it off.
No light ever since. :cool:
Well, mine sprayed out and almost gave me a hot bath. :mad: :cuss: After that happened twice in a row, I ended up just draining the rest and refill, then drive around and re-check / top it off.
No light ever since. :cool:
Burning Brakes
Joined: May 2002
Posts: 755
Likes: 42
From: Sierra Foothills, State of Jefferson
Re: Low Coolant light again! (Tim89)
I started esperiencing the 'Low Coolant' warning a few months ago. Everything checked out, plenty of coolant
This morning, after reading this thread, I actually looked in the shop manual. Looks like there is a low coolant sensor on the bottom of the surge tank. The manual does have any detail for sensor replacement, just the removal and install of the surge tank.
I would expect to find a bad connection or dying sensor. Wonder if the sealant tabs that are used (at least for LT1's) clog up the sensor? :confused:
This morning, after reading this thread, I actually looked in the shop manual. Looks like there is a low coolant sensor on the bottom of the surge tank. The manual does have any detail for sensor replacement, just the removal and install of the surge tank.
I would expect to find a bad connection or dying sensor. Wonder if the sealant tabs that are used (at least for LT1's) clog up the sensor? :confused:
Burning Brakes
Joined: Jul 2002
Posts: 871
Likes: 0
From: Costa Mesa CA
Re: Low Coolant light again! (Tim89)
I have had 3 C4's and every one had the same problem. The cure?
First, what happens. If you change thermo's, drain the system, change your fan switch or in anyway get into the cooling system, an air bubble developes and no matter how many times you fill the radiator or bottle, you'll get the low coolant light coming on.
The cure is to jack the car up in the front (one side is good enough) and take the radiator cap off and leave it overnight. In the morning the air bubble has worked it's way out and you can top off the radiator and refill the bottle and have no more probs with the light.
BIG JIM
First, what happens. If you change thermo's, drain the system, change your fan switch or in anyway get into the cooling system, an air bubble developes and no matter how many times you fill the radiator or bottle, you'll get the low coolant light coming on.
The cure is to jack the car up in the front (one side is good enough) and take the radiator cap off and leave it overnight. In the morning the air bubble has worked it's way out and you can top off the radiator and refill the bottle and have no more probs with the light.
BIG JIM
Melting Slicks
Joined: Aug 2000
Posts: 2,388
Likes: 42
From: Murrysville PA
Re: Low Coolant light again! (1Patriot)
That switch makes no sense to me. Mine used to come on also from time to time even when the rad was full. Now I run a Griffin rad with no provision for the low coolant sensor. So I just tied the wire up real nice. All summer the light never came on. The other day it came on and its not even connected!
Go figure.
Go figure.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: Low Coolant light again! (Tim89)
You shouldn't have to add anything if the system is tight and leak free, but assuming the radiator is full, apply an external ground to the sensor. If the light goes off, sensor is bad. If the light stays on, check the wire to the module for an open, otherwise the module maybe on the fritz. Unfortunately, I don't think GM makes it any more.
Thread Starter
Racer
Joined: Aug 2001
Posts: 416
Likes: 0
From: Astoria OR
Re: Low Coolant light again! (SunCr)
It doesn't always come on. Just flashes now and then. Sometimes it will stay on for a minute or so then go off. Also it doesn't always come on when I'm going fast. Sometimes just at an idle. I will try jacking it up tonight and if the air bubble doesn't come out I will get a new cap. What size cap, pressure wise, does it take?
Drifting
Joined: Jul 2000
Posts: 1,661
Likes: 4
From: Phoenix, Arizona
Re: Low Coolant light again! (Tim89)
If anyone finds the definitive cure, I'd like to know. I put a Ron Davis dual core aluminum radiator in my '89, plus I added new: thermostat, pump, hoses, etc. Everything flushed, pressure checked & no leaks. The Low Coolant light now comes on every once in a while, freeway speeds or higher. Temps running just under 180* when it happens - never higher. Has always gone out after a few minutes. If the air bubble thing works, please post! Also, is there another sensor in the overflow tank? I didn't notice one when I was cleaning mine. TIA, Paul
Thread Starter
Racer
Joined: Aug 2001
Posts: 416
Likes: 0
From: Astoria OR
Re: Low Coolant light again! (NavyVet)
Ok guys, I really feel like an idiot now. I took the cap off and was ready to jack up the front when I noticed some dried antifreeze around the tranny line, I thought it may be leaking from there but soon realized my resivor tube didn't have the clamp on it. :rolleyes: It broke off. So it was leaking from there, dripping down, and probally getting air bubbles in it. I put on a new clamp, filled it up, and let it idle for 20 minutes or so. I'll test drive it tomm. to see if that fixed it.
Drifting
Joined: Jul 2000
Posts: 1,661
Likes: 4
From: Phoenix, Arizona
Re: Low Coolant light again! (Tim89)
Tim, glad you found yours.
I checked when I got home from work - no sender of any sort on the coolant recovery tank. I guess I wasn't crazy, but I was only "pretty sure" it wasn't there when I cleaned it. I will try the "jack up the passenger side" trick this weekend.
I checked when I got home from work - no sender of any sort on the coolant recovery tank. I guess I wasn't crazy, but I was only "pretty sure" it wasn't there when I cleaned it. I will try the "jack up the passenger side" trick this weekend.