Flashing Coolant Light

[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."

[wams]

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."

(Wams - 09-07-2008) I have a 1999 911. First I drained the coolant (was the greenish yellow kind, and not the Porsche recommended one). Next I flushed the system (with high temp on) and ran regular water to remove the Preston Flush. Next I filled it with Preston Extended Life coolant (DEX-COOL, orange colored). It almost took 2 gallons, though the Owners manual states 5.95 US gallons (am I missing something?). I took the car out for a drive to be sure that the cooling system was working fine. After driving for 5 miles or so, the "RED" warning light started to flash slowly. I got back home and looked at the coolant level -> was ok; and also checked the front radiator for any air passage obstruction -> clear. The owner manual also states that engin compartment blower fan fault can cause the warning light to flash. I check the the blower fan, connected a 12 V source and it turns fine. So, I am left to wander what else could be wrong? Thanks.

[Loren]

The only way you can properly flush and fill these cars is with a vacuum system. Otherwise you will never get all the old coolant out and never get all the new coolant in.

Find an independent Porsche shop that has a vacuum flush/fill apparatus and have them change it for you.

BTW... the old Porsche coolant was greenish/yellow and the new Porsche coolant is pink.

[wams]

The only way you can properly flush and fill these cars is with a vacuum system. Otherwise you will never get all the old coolant out and never get all the new coolant in.

Find an independent Porsche shop that has a vacuum flush/fill apparatus and have them change it for you.

BTW... the old Porsche coolant was greenish/yellow and the new Porsche coolant is pink.

The Porsche dealership told me to remove the drain plug on the bottom to drain all the liquid. Put the plug back and then re-fill the coolant. The dealership did not mention anything about using a vacuum system to do the job. I will find an independent place to have this done. Also DEX-COOL (orange color) is OK? Thanks.

[Loren]

You need to find a new dealer - I think they might be incompetent.

Havoline® DEX-COOL® Extended Life Anti-Freeze/Coolant

Chevron DEX-COOL® Extended Life Antifreeze/Coolant

Are both ok for 9x6 series Porsches.

[JoshP]

You need to find a new dealer - I think they might be incompetent.

Havoline® DEX-COOL® Extended Life Anti-Freeze/Coolant

Chevron DEX-COOL® Extended Life Antifreeze/Coolant

Are both ok for 9x6 series Porsches.

Loren, what makes a coolant 'ok' or 'not ok' for a 996?

[juniinc]

No DEX-cool please,,,

there is a dexcool related class action law suit against GM/TEXACO DEXCOOL.

Since it was formulated without the addition of silicates (the corrosion inhibitors in green antifreeze) a different corrosion inhibitor strategy was needed. Organic Acid Technology or OAT is the inhibitor part of dex-cool. Unfortunately, the dex-cool is capable a rather nasty breakdown. The residue it leaves behind is very sticky, and likes to find areas in the engine and other areas to "drop out" or "fall out " of solution and stick to the wall surface of engine and radiator.

In many cases, the orange mud hardens, and seems to expand or push the gasketed surfaces out of position, causing leaks.

My Chevy 3.4was filled with DEXcool for a couple of years,,,and the result was waisting 4 precious HRS(just hate to work on a chevy)last Sat day for complete tear down

The only way you can properly flush and fill these cars is with a vacuum system. Otherwise you will never get all the old coolant out and never get all the new coolant in.

Find an independent Porsche shop that has a vacuum flush/fill apparatus and have them change it for you.

BTW... the old Porsche coolant was greenish/yellow and the new Porsche coolant is pink.

The Porsche dealership told me to remove the drain plug on the bottom to drain all the liquid. Put the plug back and then re-fill the coolant. The dealership did not mention anything about using a vacuum system to do the job. I will find an independent place to have this done. Also DEX-COOL (orange color) is OK? Thanks.