blinking temperature light

[hugo kohl]

99, c2, 120k

Upon startup I get a red blinking light on my temperature gauge.  Car has not been overheating, coolant level is good, engine compartment fan is good and I don't have any coolant leaks.  I changed my coolant tank out about 6 months ago and everything has been fine since.

 

Any suggestions?

[B3-CPO]

40 minutes ago, hugo kohl said:

99, c2, 120k

Upon startup I get a red blinking light on my temperature gauge.  Car has not been overheating, coolant level is good, engine compartment fan is good and I don't have any coolant leaks.  I changed my coolant tank out about 6 months ago and everything has been fine since.

 

Any suggestions?

Have you removed the bumper and cleaned the front radiators in the last year or two?

 

Also, you should check your water pump. If it hasn't been changed in the last 20K miles, I would plan to replace it. There's a slight chance the impellers have broken off and blocking some of the coolant passages. Let's hope not. 

[Loren]

Covers all Carrera (996), GT3, TT / GT2 and Boxster (986) cars

Here is the long explanation from the service manual on the flashing coolant light.

"Four functions of the coolant warning light:

1. Engine coolant level too low -- light flashes slowly (0.5 Hz)

2. Engine compartment temperature too high -- light flashes slowly (0.5 Hz) (engine compartment blower might be faulty)

3. Engine coolant temperature too high -- light is lit; pointer on the right

4. Temperature sensor at water outlet faulty -- light flashes rapidly (1 Hz) ; pointer on the right

Note: The temperature warning in point three is indicated if the conditions "engine coolant temperature too high" and "engine coolant level too low" are present simultaneously."

[wizard]

If none of the above, check your battery and check the electrical component of your ignition switch.

[B3-CPO]

2 hours ago, hugo kohl said:

99, c2, 120k

Upon startup I get a red blinking light on my temperature gauge.  Car has not been overheating, coolant level is good, engine compartment fan is good and I don't have any coolant leaks.  I changed my coolant tank out about 6 months ago and everything has been fine since.

 

Any suggestions?

Question for clarity... You said "car has not been overheating", but is the car overheating now when you're getting the warning light? What is the temp reading on the gauge when the light is blinking?

[hugo kohl]

I replaced my water pump and thermostat at the same time as coolant tank so I don't see this as a problem and in any case, the car is not overheating, rather it is running at ideal temp.

 

Im wondering if it could be the wires connected to the coolant tank sensor and will be checking these next.  

[B3-CPO]

1 hour ago, hugo kohl said:

I replaced my water pump and thermostat at the same time as coolant tank so I don't see this as a problem and in any case, the car is not overheating, rather it is running at ideal temp.

 

Im wondering if it could be the wires connected to the coolant tank sensor and will be checking these next.  

Then I would follow Loren's instructions from the shop manual to more closely identify the culprit. 

[wyovino]

My guess is the coolant tank level sensor.  I recently changed my coolant tank and got a blinking temp light when I was done. It turned out that I broke the level sensor in the process. The damage wasn't obvious but a new level sensor fixed the problem.  An inexpensive Wifi or Bluetooth ODBII reader will be able to tell you the engine compartment and coolant temps in real-time.

Edited July 31, 2018 by wyovino

[kbrandsma]

Unless you used a vacuum fill to refill the water/anti-freeze after after your waterpump replacement.  You may have had some air in the lines.  Top it off and monitor water level.  Maybe flip your bleeder valve up till all air has escaped.

Edited August 1, 2018 by kbrandsma