Low Coolant Light Blinking - A Few Questions

[rick3000]

Hi Everyone,

Last night, I noticed my coolant light slowly blinking. I pulled over and checked the manual, it looks like that light indicates a low coolant level. My 986 was not running hot at all, and was right around the 180 mark.

After discovering the coolant was in fact low, I headed for the closest store to buy some distilled water. On the way the light stopped blinking. I added about a quart of distilled water anyway to get it back within the minimum/maximum level when cold. (I realize the level fluctuates while the engine is hot.)

A quart when the car takes about 6 gallons of a 50/50 water/coolant mix isn't much, but I have a few questions I'm hoping someone can help me with:

-Will throwing the 50/50 mix off cause any issues?

-What could have caused the coolant level to deplete? I have not noticed any leaks near the tank, in the trunk, or under the car. No white crystals anywhere.

-Is there anything I should check, or have checked?

-Should I do a coolant flush? The water pump is fairly new, and the last coolant flush was earlier this year.

-In the future, is there anything I can do to avoid an air bubble in the coolant tank if I do have to top it off again? I think I avoided that issue this time, but I know it can be an issue.

Thanks!

[BruceH]

The coolant level sensor on these cars seems to be pretty sensitive. This happened to me about a year ago. I added a little distilled water and that was the end of it. Since you just had your coolant changed, no, you don't need a flush. The little bit that you added will be fine as far as your mixture goes.

[Joe B]

+1. Mine did the same thing about a year ago. No leaks anywhere, I added about 1 quart of 50/50 (I need the antifreeze in the mix because it gets cold here ) and it's been fine ever since.

[Burg Boxster]

What you added in distilled water did little to change mix - no worries.

Losing coolant though is an issue b/c it is a CLOSED pressurized system. Coolant is only lost when a part of the system is compromised: radiator, head gasket, tank cap, relief valve, oil cooler, water pump, coolant reservoir, etc. Now, maybe when you had H2O pump changed they let a large bubble in system which finally burped itself out. Doubtful but how long ago was pump changed? Otherwise, have a quick pressure test done on the system to see if it holds and go from there...

Good luck

[rick3000]

Thanks everyone! I am doing the 90k service this week, so I will make to sure to check pressure test the coolant system and give all the lines a once over.

[CrashTest]

Originally Posted by Burg Boxster

What you added in distilled water did little to change mix - no worries.

Losing coolant though is an issue b/c it is a CLOSED pressurized system. Coolant is only lost when a part of the system is compromised: radiator, head gasket, tank cap, relief valve, oil cooler, water pump, coolant reservoir, etc. Now, maybe when you had H2O pump changed they let a large bubble in system which finally burped itself out. Doubtful but how long ago was pump changed? Otherwise, have a quick pressure test done on the system to see if it holds and go from there...

Good luck

I had this issue this summer, some weeks after I had my water pump replaced. Coolant would "disappear" with no smells, puddles, or white smoke. Later, the car would run a little hot in traffic.

I opened the bleeder on the reservoir (remove the black "shroud" under the coolant and oil caps). I topped off the tank and drove it with the bleed open for a week or two. Never had the problem again.