Low coolant light on...

[T-Red SVT]

My low coolant light is on. It has been for a while now. First thing I checked...coolant level...low, filled her up, and found out I had a water pump problem, only to find out the water pump was fine, it was the water pump housing. Had replaced. Get car back and the light is still on. I'm like, wtf? Bought a new sensor thinking that is the problem. Nope. Light is still on.

What is the deal?

--Andrew

 

[mnewxcv]

try filling it a little over the max mark. are you parked uphill?

 

[contourspd98]

I had a problem with my light being on after my 3L install. It was on for about 3wks. After the install i ran it for a while and kept the fluid filled. Than a couple weeks later i checked the level and it was low. Topped it off and hasnt been on since. I think that there was just an air pocket in it somewhere and it finally festered out.

Just keep driving it for a week and keep an eye on the level and see if it goes out.

 

[Heywood]

My low coolant light is on. It has been for a while now. First thing I checked...coolant level...low, filled her up, and found out I had a water pump problem, only to find out the water pump was fine, it was the water pump housing. Had replaced. Get car back and the light is still on. I'm like, wtf? Bought a new sensor thinking that is the problem. Nope. Light is still on.

What is the deal?

--Andrew

The general consensus around here is to keep the coolant about 1/2" over the max line. Not to say there's not something else at play but be sure its well topped off to eliminate that as the cause.

 

[T-Red SVT]

To all of the above:

The tank is filled to about half and inch to an inch from the top of the reservoir. The light has been on for about 2 weeks.

I did notice today when I changed the sensor that there was a lot of dirt and grit in the reservoir...almost like it was stuck to the bottom of it. Could this
be a cause?

I am getting scarred because I read somewhere that it could be the head gasket or something of that nature. The car runs great...other than my P0420 and P0430 codes (which I am in the process of figuring out). Although, something weird:

When I start moving after the car is completely cold and I accelerate quickly, there is almost a hesitation/missing sensation. I would not call it a miss, though. Once the car warms up, it is gone until the next time it is cold. What could this be?

 

[Heywood]

The head gasket should only be a concern if you are losing coolant.
You could try taking the coolant reservoir off and flushing it to try and remove the dirt, but mine is similar and didn't come out with 5 minutes of running a hose through it. Is the passage to the sensor clean?

 

[AliasJerk]

The head gasket should only be a concern if you are losing coolant.
You could try taking the coolant reservoir off and flushing it to try and remove the dirt, but mine is similar and didn't come out with 5 minutes of running a hose through it. Is the passage to the sensor clean?

I agree with heywood, the dirt in the tank could create some confusion for the sensor, however I would start tracing wires to the sensor, if the wiring insulation is flaking and two of the wires are touching each other, it could trip the light.

I know after I put my motor back in my car I had to refill all of the fluids, I topped off the coolant tank and drove it for a month and the coolant light popped on, whenever it came on it would only be on a cold start and after about 2 blocks of driving it would turn off, added coolant, problem went away.

here is a stupid set of simple questions, have you reset your car's computer? is your temperature gauge working properly? have you replaced the coolant temperature sensor?

 

[T-Red SVT]

The head gasket should only be a concern if you are losing coolant.
You could try taking the coolant reservoir off and flushing it to try and remove the dirt, but mine is similar and didn't come out with 5 minutes of running a hose through it. Is the passage to the sensor clean?

What do you mean, the passage to the sensor? Inside of the tank?

I was a bit surprised when I replaced the sensor that it wasn't physically inside of the reservoir and in contact with the coolant. I was totally expecting to have coolant come flooding out when I swapped the new sensor in. It was rather funny come to think of it. I was tipping the tank so that as little coolant as possible would come out.

 

[T-Red SVT]

I agree with heywood, the dirt in the tank could create some confusion for the sensor, however I would start tracing wires to the sensor, if the wiring insulation is flaking and two of the wires are touching each other, it could trip the light.

I know after I put my motor back in my car I had to refill all of the fluids, I topped off the coolant tank and drove it for a month and the coolant light popped on, whenever it came on it would only be on a cold start and after about 2 blocks of driving it would turn off, added coolant, problem went away.

here is a stupid set of simple questions, have you reset your car's computer? is your temperature gauge working properly? have you replaced the coolant temperature sensor?

Reset the computer as in with an OBDII reader? No. I didn't think that that would turn the light off. Does the ECU really run the sensor? (Maybe that is a dumb question as it runs everything). I can try it. I do work at Autozone.

My temperature gauge works fine. It never gets above half. It was weird, after I changed spark plugs and wires a month ago, the car wouldn't get as hot. I suppose that makes sense since the plugs are new and not fouled up with carbon deposits.

Coolant temperature sensor? Why? How would that throw my low coolant light? I suppose I could try that too. Would it work?

 

[AliasJerk]

Reset the computer as in with an OBDII reader? No. I didn't think that that would turn the light off. Does the ECU really run the sensor? (Maybe that is a dumb question as it runs everything). I can try it. I do work at Autozone.

My temperature gauge works fine. It never gets above half. It was weird, after I changed spark plugs and wires a month ago, the car wouldn't get as hot. I suppose that makes sense since the plugs are new and not fouled up with carbon deposits.

Coolant temperature sensor? Why? How would that throw my low coolant light? I suppose I could try that too. Would it work?

Reset the whole computer, take the positive cable off of the battery for about 10 minutes then re attach. That would be your first step of action, although some people have said that a dirty coolant tank causes the coolant level light to pop on occasionally.

 

[T-Red SVT]

Reset the whole computer, take the positive cable off of the battery for about 10 minutes then re attach. That would be your first step of action, although some people have said that a dirty coolant tank causes the coolant level light to pop on occasionally.

I cleared the ECU today at work. Low coolant light still on, but CEL is off! For a while at least.

I don't know how unhooking the battery will do anything, but I guess it couldn't hurt.

 

[JoeM]

I cleared the ECU today at work. Low coolant light still on, but CEL is off! For a while at least.

I don't know how unhooking the battery will do anything, but I guess it couldn't hurt.

Unhooking the battery Clears the stored codes in the ECU.
It allows the ECU to go back to a normal operation until it finds something to complain about during its Cold/Hot Cycle.

 

[AliasJerk]

at this point I would clean out the coolant tank, and if the problem still persists, start checking the wiring leading to the sensor, might have a short somewhere.