idiot light is being an idiot

[Elixer]

I see the low coolant idiot light come on every so often, but, I check the reservoir and the radiator itself and they are both full. It stays on for say 20-30 miles, then off for X miles, then will pop on again seemingly randomly.
Sometimes, can go for days without seeing it as well.

This is on a 3800 series engine, and I suppose the sensor is glitching out.

Would disconnecting it do any harm?
I check fluid levels at every fill up, so, not sure what good it is, unless, it is trying to say something else can be wrong here?
Heater works fine.

A friend said to change the radiator cap, but, dunno what that is going to accomplish?

The last flush was at 65K miles, it has 80K now.
Temp gauge rarely goes more than half way up.

So, is it a faulty sensor that I can disconnect, or something else?

*edit, forgot to mention, for the reservoir, the cap is connected to a tube, but the end of the cap don't have a hose going into the fluid itself, is this the discharge for the radiator, dumping fluid back into it?

 

[thescreensavers]

What is this picture of ants?

Low temp could mean a couple things, do you have an IR gun to check the thermostat housings temp?

Low coolant temp could also be from a stuck open thermostat, bad sensor..etc

 

[master_shake_]

if you look down by your water pump you will see 2 plastic elbows that go the the engine timing cover to the belt tensioner assembly they are known to crack and leak.

i suggest you check there first.

https://www.youtube.com/watch?v=3OH8Mx_YKHQ

also consider changing your thermostat.

the temp gauge should be near 210 which is operating temperature

 

[tortillasoup]

I see the low coolant idiot light come on every so often, but, I check the reservoir and the radiator itself and they are both full. It stays on for say 20-30 miles, then off for X miles, then will pop on again seemingly randomly.
Sometimes, can go for days without seeing it as well.

This is on a 3800 series engine, and I suppose the sensor is glitching out.

Would disconnecting it do any harm?
I check fluid levels at every fill up, so, not sure what good it is, unless, it is trying to say something else can be wrong here?
Heater works fine.

A friend said to change the radiator cap, but, dunno what that is going to accomplish?

The last flush was at 65K miles, it has 80K now.
Temp gauge rarely goes more than half way up.

So, is it a faulty sensor that I can disconnect, or something else?

*edit, forgot to mention, for the reservoir, the cap is connected to a tube, but the end of the cap don't have a hose going into the fluid itself, is this the discharge for the radiator, dumping fluid back into it?

there are two caps. one for the radiator and one for the fluid overflow reservoir. The overflow reservoir has provisions to suck and push fluid into the cooling system. It also allows for fluid to leak out of the system entirely onto the ground if overfilled. The radiator cap just pushes and pulls fluid from the overflow tank while still keeping the radiator pressurized.

 

[darkswordsman17]

Not sure how you could check this, but there's a common problem with these engines and gaskets (trying to remember which one exactly, I want to say the intake gasket), where they're prone to failing (used plastic and the area is prone to getting hot and melting it) and cause the engine to suck coolant. This happened to my Mom's car (I want to say there was even a recall over it but I don't know for sure). Symptoms started like that, and we thought it was a bad sensor, but it gradually got worse until it finally hydrolocked the engine.

Not saying it is that, and if there's no coolant loss at all then I wouldn't think it'd be that, but might be something worth checking.

 

[tortillasoup]

Not sure how you could check this, but there's a common problem with these engines and gaskets (trying to remember which one exactly, I want to say the intake gasket), where they're prone to failing (used plastic and the area is prone to getting hot and melting it) and cause the engine to suck coolant. This happened to my Mom's car (I want to say there was even a recall over it but I don't know for sure). Symptoms started like that, and we thought it was a bad sensor, but it gradually got worse until it finally hydrolocked the engine.

Not saying it is that, and if there's no coolant loss at all then I wouldn't think it'd be that, but might be something worth checking.

agreed, forgot about that issue. look for tsb/bulletins in regards to your vehicle op.

 

[master_shake_]

Not sure how you could check this, but there's a common problem with these engines and gaskets (trying to remember which one exactly, I want to say the intake gasket), where they're prone to failing (used plastic and the area is prone to getting hot and melting it) and cause the engine to suck coolant. This happened to my Mom's car (I want to say there was even a recall over it but I don't know for sure). Symptoms started like that, and we thought it was a bad sensor, but it gradually got worse until it finally hydrolocked the engine.

Not saying it is that, and if there's no coolant loss at all then I wouldn't think it'd be that, but might be something worth checking.

it wasn't the intake gaskets it was the upper intake manifold.

coolant would get in to the egr port and fill the cylinders.

 

[Z15CAM]

Try disconnecting the battery for an hour so that it resets the on board ECM computer.

May be your dash will respond.

Other then you know your fluid level is OK you may have a bad Sensor or bad wiring to that sensor.

Hate these modern cars.

 

[jaha2000]

Not sure how you could check this, but there's a common problem with these engines and gaskets (trying to remember which one exactly, I want to say the intake gasket), where they're prone to failing (used plastic and the area is prone to getting hot and melting it) and cause the engine to suck coolant. This happened to my Mom's car (I want to say there was even a recall over it but I don't know for sure). Symptoms started like that, and we thought it was a bad sensor, but it gradually got worse until it finally hydrolocked the engine.

Not saying it is that, and if there's no coolant loss at all then I wouldn't think it'd be that, but might be something worth checking.

Thought that was a 3400 issue mainly.. (I did it on mine)

 

[LTC8K6]

Yeah, just take a good look at that level sensor on the tank to see if there is a wiring or connector problem.

You might take the sensor out and clean it and it's contacts, and see if that fixes it.

That's what I'd try.

A new sensor can't be that much, can it?

 

[bruceb]

On the GM 3800 engine the Low Coolant Sensor is in the radiator tank (passenger side) a few inches below the Upper Radiator Hose ... It is held in with a simple clip and they do have a habit of getting gunked up a bit. Easy to remove and change out. That sensor does have a habit of needing replacement now and then. If it was the Upper Intake Gasket, you would have a definite need to be adding some coolant. But since you are not, it is most likely just a bad level sensor.
From your temp gauge picture, I would say you have a 1999 Grand Prix (same car I have) and where your temp gauge is pointing to, is exactly where it should be on a properly functioning cooling system on that car.

Note: When the Upper Intake fails it is around the 100K miles area. If it does fail and you get a severe misfire, shut the engine down quick, before the coolant gets to main crank bearings.

 

[Elixer]

On the GM 3800 engine the Low Coolant Sensor is in the radiator tank (passenger side) a few inches below the Upper Radiator Hose ... It is held in with a simple clip and they do have a habit of getting gunked up a bit. Easy to remove and change out. That sensor does have a habit of needing replacement now and then. If it was the Upper Intake Gasket, you would have a definite need to be adding some coolant. But since you are not, it is most likely just a bad level sensor.
From your temp gauge picture, I would say you have a 1999 Grand Prix (same car I have) and where your temp gauge is pointing to, is exactly where it should be on a properly functioning cooling system on that car.

Note: When the Upper Intake fails it is around the 100K miles area. If it does fail and you get a severe misfire, shut the engine down quick, before the coolant gets to main crank bearings.

Yeah, forgot to mention it is a Grand Prix.
Guess I got some things to check (to bad I don't have a IR temp gun) this weekend.

Thanks for the tips/info!

Oh, isn't dexcool always supposed to be orange? It seems to have turned into greenish orange now, dunno if that is from sludge from someplace?

 

[BlitzPuppet]

Yeah, forgot to mention it is a Grand Prix.
Guess I got some things to check (to bad I don't have a IR temp gun) this weekend.

Thanks for the tips/info!

Oh, isn't dexcool always supposed to be orange? It seems to have turned into greenish orange now, dunno if that is from sludge from someplace?

The sludge would definitely be brown. Greenish orange sounds like it was maybe mixed with conventional anti-freeze.