So I'm driving home last night and the low coolant light in the '99 Monte starts flashing. Oh crap. Immediately my blood pressure rises as my mind runs through all the things that could be wrong. Bad hose, cracked radiator, bad or gunked up sending unit, Lower Intake Manifold. After a minute the light goes out. Today everything looked ok. Coolant is full, oil ok (no coolant there). Coolant is only 8 months old. So, hopefully it was just a fluke. Drove 25 miles this morning with no light, but I'm still keeping my fingers crossed.

 

Well, the low coolant level light is now flashing constantly, so I pulled the sensor and it looked clean. I just ordered a new one from RockAuto. It was only $39.62 and that included shipping. So, hopefully that'll fix my problem.

 

My low coolant light was unplugged when I got my car, I plugged it in and it started flickering at me... I just unplugged it again and closely monitor the coolant level and engine temp

 

Mine is doing the same thing...was wondering if the sensor replacement helped? It just freaks me out when it flashes...I can drive it to and from work (80 miles) and it never flash...then all the sudden there it goes along with my heart rate and blood pressure...lol

 

I did add some "Prestone 50/50" for ALL cars...and I think it said it didn't matter what color the car had in it.....I added a small amount because it was showing that my fluid was not truely low....please tell me I didn't mess up by not using the "Dexcool"

 

JaxJim - Hope the sensor fixed your problem

Ablond - I would not mix anything with DEXCOOL, even if it says mixes with all colors. Do a google on DEXCOOL, I don't need to go on about it here, enough has been said.

I had the Coolant light come on in my T/A, it was full, I did a coolant flush and switched to Green, been two years now it has never come back on.

 

Good to know - thanks so much!!!!

 

My light is possessed too.
Here's how mine went:
Thermostat bad, replaced, replaced DexCool at the same time (hubby only drained and refilled, figured half new would be better than none I guess, did NOT flush - which I think is the culprit). Then my low coolant light decided to appear off and on, but it wasn't low. Replaced sensor, it's still there, comes and goes whenever it feels like it. I want to go ahead and flush the system and start over but it's a royal PITA as my radiator does not have a draincock so it's to undo the hose that you can't get too easily.

 

will the tranny out of a 3.4 fit a 3.1

 

I put the new sensor in, and all is well. No lights flashing. So it looks like the sensor was the problem.

I didn't mess with the drainplug on this radiator when changing it out. The draincock feels rather cheap, so I just pulled out the old sensor then stuck the new one in without loosing too much coolant. What did leak, I caught in a pan and poured it back in.

I'm using Prestone in the Monte. It's orange - sorta like the Dexcool and I believe it is also a 5 year coolant. It still looks good - not cloudy or anything. Looks like orange soda. Doesn't taste nearly as good, though.