Blinking Temp & Coolant lights. 99 SL1

The Temperture and Low coolant lights blink simaltaniously on my 1991 SL1
until the engine gets to normal operating temperture. Then they usually go
off, but sometimes they will start blinking again. The coolant level is
full (I just flushed the system and refilled to be sure that wasn't the
problem. All other fluids are at the full level. The car is not
overheating (the temp. gauge never goes much past the first mark). Any
idea what is causing these lights to blink? Nothing said about it in the
owners manuel.

 

I recently flushed and filled my coolant system and had the same issue.
Bubbles, I suppose, in the system took on more coolant as the bubbles left
the system. I just topped it off when I noticed my FULL-Cold line wasn't
quite full. Nary a problem since.

Otherwise, it might be a sensor issue. Check the obvious first (levels) and
proceed from there. Good luck.

Barry
'94 SL2 167000 miles.

 

I have a 99 SC2 that started doing this recently as well. I had plenty of
coolant in the system and in the reservoir (although I would hear some
gurgling as the engine revved up from a stop; this has been the same for
over 3 years).

I checked the tranny fluid level, and it was slightly low, so I topped that
off. Contrary to what reex01 wrote, the function of the light IS mentioned
in the manual, but you have to look for it under the explanations for all
the dashboard telltales (it's not listed in the manual index). All it says
there really is that either you are low on coolant and the engine is due to
explode, or you are overheating the transmission due to driving conditions
or low fluid and the tranny is due to explode (well, not really, but you get
the picture).

But I agree with Barry: if the fluids are good (and this sensor is only
supposed to pertain to coolant and tranny fluid), the next logical step is
the sensor acting up. BTW, I got no engine service codes when I hooked up a
scanner to the connector on the dash.

I have the Saturn service manuals for the 99's (4 big books, covers all
models) and will look this up further and see what it entails (I'm home
recupperating, so I can't actually do the work, only read about it.)

Dave

 

My 97 SL2 w/manual trans did that and I kept topping off the tank. Then it
started throwing-up after I shut it down and would spill some coolant into
the driveway. Finally the dealer put a new cap on the reservoir and the
throwing-up and the flashing light prob stopped. ...just a thought.

 

I'll lay odds you have a blown head gasket or cracked head. You may not be
seeing anything (coolant in oil or vice versa) but I can almost guarantee
that's the issue.
Larry

 

Larry:

That seems a bit extreme for the condition indicated by the flashing dash
light. There are no symptoms on my 99 SC2 which would indicate a blown head
gasket (I'm not losing any coolant, there are no oil leaks, engine runs
evenly).

Would you have other evidence for your diagnosis of a blown head gasket for
my car, or are your comments directed to the original poster (reex01)?

Dave

 

directed at the sympoms you mentioned. that gurgling noise you hear is air
in the cooling system. Many times a HG will go or a head will be cracked and
there will only be some strange indicatior behavior and or the noise you
mentioned. What happens is exhaust gasses find there way into the cooling
system. The can be checked by using a device that "sniffs" for combustion
gasses in the cooling system. I would advise you to not ignore it and have
this checked.
Larry

 

Okay, yeah, I can agree with that, idea, but as I mentioned it's been this
way since I got the car in 2001. I'll bring it to a shop that has something
that can pick up on exhaust gasses in the coolant reservoir. I guess it
would be similar in function to the one I have that finds R-12 refrigerant
leaks?

Dave

 

It's device filled with liquid that sits on top and seals the coolant tank.
If combustion gas is present than the liquid changes color.
Larry