Low Coolant Warning

[TenGHz]

A few weeks ago I got a low coolant level message on my DIC.

I checked the coolant level shortly after getting the message. The car was warm, just about got up to running temp. The pressurized reservoir was to the full cold line.

The message was only on for a few minutes and went off on it's own. I didn't see it for about another week and it came on and went off just like before. This was only once as well, and I didn't see it again for a few days.

Starting yesterday I've seen the warning every time I start my car when cold. It comes on for a minute or 2 and goes off. If the car is warm, the message doesn't show up. I also figured that if there is a low coolant issue the message would stay on the DIC and not go off after a few minutes - just like the low fuel message.

My question is that since the reservoir looks full, could it a coolant level sensor going out or some internal problem?

The heater works fine. I can see on the temp guage when the t-stat opens, so I think coolant is circulating fine. But, just looking for some thoughts.

[harofreak00]

Had the same problem with my GXP. Said low coolant, never was. I think its a common problem. Not sure a new sensor would fix it or not.

[dpnewfie]

Had the same issue with mine some time ago. Simply topped off the reservoir and hadn't seen the message since.

[CMNTMXR57]

Well, there are about 3 - 5 threads here on this section about Northstar coolant leaks that will answer ALL your questions. Your symtoms are exactly what we've all been through and they always happen on a cold N* in colder temps.

If you're up to operating temperature and your coolant resevior is at the cold line, you are in fact low! It is NOT a sensor issue. Although, with Dexcool, it is common for sensors to gunk up and give false readings, this appears not to be the case here. When warm, your resevior should be above the cold line by about a half inch or so. When cold, it should be right at the mid-point where the black portion of the resevoir meets with the clear portion (that is the cold line).

See the other threads here, it'll answer all questions.

[TenGHz]

When the car is cold it is on the cold full line. My old '01 SE would do the same - take a bit after getting warm before start filling the reservoir on cold winter days. When I checked it, it hadn't completely reached operating temp.

From what I'm finding I'm not going to worry about it till the tank level falls, or the car starts overheating.

I don't think there is a leak, or at least not one that I've been able to find externally.

The reason I say that is because the warning turns off even before the t-stat would be opening and filling the reservoir.

[CMNTMXR57]

The thing is, the coolant burns off one the engine warms up. That is why I you don't see any tell tale signs of leakage. It took me forever to find mine and I knew it was leaking.

[donky4444]

My issue started the same way, just a warning light at start up until it reached temp but was really never low. I had a complete coolant system flush and fill with the GM stop leak tablets put in and it stopped. If you haven't done a coolant flush it may be a good time. I read on Cadillac forum that you should do one every 2 years with the N* due to the head gasket issues they tend to get. It's a worth while maintenance to do.

[TenGHz]

I had a complete coolant system flush and fill with the GM stop leak tablets put in and it stopped.

Probably not a bad idea. More than likely the system's never been flushed yet anyways. I just got the car last September, and I know I haven't done it since then. I'm guessing the PO didn't do it either...

[laxmangl]

The same thing happened in my moms aurora . Hers never read anything but perfect, so we are pretty sure the sensor is fouled


EDIT: wth am I thinking, I take back everything I said, I completely forgot about my moms most recent coolant dissapearance.