Low coolant light came on--Holy Crap!

rjirvine · April 22, 2006

I was driving down the freeway today and got a "low coolant" message. As you can imagine, I about crapped my pants. In my minds eye I could see a lower heater hose cut by a belt and spewing coolant all under the underside of my truck, followed by the engine seizing. Well, I was only about a mile from my friends house and the temp looked normal so I simply drove to his house.

When I popped the hood the level was only about 1/2" below the "cold fill" mark. I havn't seen an issue with false indications on the forum here, so was wondering...exactly when does the light come on? I added some 50/50 mix of dexcool to about 1/2" above the cold fill mark and the light never came back on.

Bob 2000 Ext cab Silverado 4x4 w/ 5.3

redvett · April 22, 2006

Even if you didnt have any coolant the engine is designed to get you home at reduced power and not hurt the engine. The PCM will reduce power and allow you to run at slowly to a service place. Its in the owners manual .

GOOSE · April 22, 2006

I had the same issue. Took it to the dealer. They said that there is as level sensor in the tank that will trip the light. So, if it does get a little low in the tank it can trip the light.

ken1mod · April 22, 2006

there is no problem here. everything worked as designed. add some coolant. low coolant level means just that. Not engine overheat. The chevy cooling sysem warning system is better than almost all others. Two (one early) warnings of a potential problem.

ken

tryn2lrn · April 23, 2006

"so was wondering...exactly when does the light come on?"

I guess about 1/2" below the "cold fill" mark.. Sorry!

But now we know...Thanks

pm26 · April 23, 2006

Even if you didnt have any coolant the engine is designed to get you home at reduced power and not hurt the engine. The PCM will reduce power and allow you to run at slowly to a service place. Its in the owners manual .

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It probably has a similar system as my fuel injected boat V8 engine (302 Ford).

My boat engine has raw water cooling and one time the raw water pump impeller sheared off while I was doing over 50 MPH in the boat. The temperature shot up instantly and then the PCM would not allow the engine to run over idle speed. After about 10 minutes of that, it started retarding timing to the point where the engine would not even run. No damage at all was done to the engine, it started right up after it cooled down (after new raw water pump was installed).

RyanZ71 · April 23, 2006

General Moron's sensors really suck! First the fuel guage sensor, now the stupid Coolant level sensor. Next we will have low oil warnings going off.

az'03Silverado · April 23, 2006

Whoa, relax Ryan. It sounds like it worked just fine. It's better to have the warning than to get stranded in B.F.E. You want annoying? Try getting a crack in your windshield washer tank and having a choice of dripping water everywhere (and filling often) or having the message center flash "check washer fluid" every 10 seconds. It was worth the 30 bucks to replace the tank.

pm26 · April 23, 2006

Whoa, relax Ryan. It sounds like it worked just fine. It's better to have the warning than to get stranded in B.F.E. You want annoying? Try getting a crack in your windshield washer tank and having a choice of dripping water everywhere (and filling often) or having the message center flash "check washer fluid" every 10 seconds. It was worth the 30 bucks to replace the tank.

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Better yet: My Mazda 626 V6 I had a tiny crack develop in the coolant overflow bottle that would cause coolant to leak very slowly. Hot coolant got into the A/C compressor clutch harness connector directly under the plastic bottle, and caused extremely annoying intermittent A/C malfunction. The car was still under warranty, but I had all kinds of A/C components replaced for no reason and they could not find the problem. Fnally, after the A/C quit, they found the coolant leak and replaced the coolant bottle and cleaned the harness connector. That fixed the A/C for good. 70k miles later, the new bottle leaked again and I had to replace that one at my cost (about $ 80). Seems like all vehciles have weird issues, some for than others.

RyanZ71 · April 23, 2006

I'm talking about the sensors, not cracks in the tanks. A real weak link in the GM vehicles.

rjirvine · April 23, 2006

Thanks for the input guys. So, I guess the light comes on about 1/2" below the cold fill mark..that's okay by me. As was mentioned earlier-I'd rather be warned too early than too late of course.

As far as some have mentioned about cracked windshield washer tanks, I have used "aquarium sealer" on various carpet cleaner water tanks etc. around the house. You can get a tube of it at Wal-Mart pretty cheap. I don't know if it would be any better than RTV to seal a crack in plastic, but I think it would. I'd just rough up the area with some sand paper and put a wide coat of sealer on. I think it would at least hold until you wanted to spring for a new tank. Just a thought.

doverarjim · April 23, 2006

My truck will sometimes do it when it is on a road with a big crown in it. I have learned to be carefull about which lane I am in.

Worktruck · April 23, 2006

My 02 has had the "low coolant" light come on twice in it's 84K existance. Great that the light comes on to let you know your low, but my question is "Where has the 1/2 gallon of coolant gone?" No one seems to know the answer to that question. Hmmmmmmmmmm.