Driving home on a beautiful day, windows down, sunroof open, when the temp jumps to about 210 and flashes red light. Coast into driveway, tow it into garage and contact PO. He states that it has always gotten hot and bitched (red light) but never over heated. Ha! At least he was honest. Thoughts on what it is? Obviously it's not a head gasket so does that mean cracked head? I'm assuming a stuck thermostat would be way to simple.

Checked coolant and it is above Max line in reservoir.

 

Need more info....the light should not go on at 210, or I don't think it should.

Wait for it to cool....remove the expansion tank cap, inspect coolant, is it pink or a milkshake? Look in oil add tube....any milkshake in there?

 

I know you said you checked the coolant - you confirmed that the liquid is actually there and not just a line on the old tank? I'm not accusing you of being dumb - but it's easy to misread the older tanks that are funky and no longer transparent.

Check the position of the ambient air temperature sensor in the engine compartment.

Finally, get those radiators cleaned out (the space between the radiators and the AC heat exchanger). If there's not actually a problem with the cooling system, check for garbage packed around the radiators...

 

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

(1Hz = 1 flash per second. 0.5Hz = 2 seconds per flash)

 

Ok, I've stopped hyperventilating. Coolant is pink and confirmed above max level. Oil is at mid level and and a decent shade of brown (changing it this weekend.) The blinking seemed to be 1 Hz. Haven't been able to find the ambient temp sensor yet but still researching.

Edit: Almost no debris in front of radiators. Obviously has been cleaned out recently.

 

check the coolant reservoir cap.

 

https://rennlist.com/forums/996-foru...ing-issue.html

See 2nd page of linked thread.

 

Winner winner chicken dinner! Ambient sensor was hanging off to the side against the block. Any tips for getting that frickin thing grommet back in its slot? Read the part about not disconnecting it, that seems like wise advice.

Edit: figured it out. You have to slide it in from the side. Back business!! Thanks to 5Chn3LL and everyone for helping troubleshoot and solve this. Rennlist rocks!!!