I joined the forum two days ago to ask about a catatylitic converter but today I want to address an overheating issue (or least the light coming on.) When I got the car I noticed that he coolant was pratically empty so I refilled the expansion tank and drove around. The light and stage 2 fan came on so I thought there was air in the coolant system so I cracked the bleeder screw to let out any air bubbles. There didn't seem to me many although since the systme was pressurized, coolant came out of the bleeder hole as well so I am not sure.

What I did notice though was that the stage 1 fan didn't come on at all while I was driving. I have several questions: 1. When should the stage 1 fan come on and is the resistor for that stage shot? Should I get a new fan assembly and do the old move the radiator rail out of position trick to replace it? Is the resistor replacement hack described here somewhere worth it or it is easier (more expensive to get a new fan) 2. Do I have to keep bleeding the system over the course of days to purge all the air? Is it worth using my shop vac to suck out all the air again according to someone on this forum. 3. Is there any way to see if the water pump is turning and/or thermostat sticking? There doesn't seem to be movement in the expansion tank when the cap is off like on older cars.

Thank you for any help.

 

An update is that I found a small crack in the Coolant reservoir so I replaced that since I knew that would be a problem anyway.

I have tried to bleed the system by running it with the heater on and fan on low and cracked the bleeder screw but not much air or coolant came out. Now I have parked it and will wait until tomorrow when I can get my shop vac and try the ol' shop vac bleed technique and also bleed manually again.

Is a small crack in the Reservoir enough to make the car overheat? I guess it wouldn't hold pressure with a crack.

 

The crack would allow coolant to escape once heated and under pressure. That escaped coolant could be vaporizing on your exhaust and you might not see a puddle under the car. The coolant must be an operating temperature (at or over boiling on these cars) to maximize the bleed process. If once that is done you're still not getting pressure/fluid via bleeding then your next step would be to check/replace the thermostat. Didn't solve the issue? Water pump replacement. Take it in the steps that I've laid out from the least expensive to most expensive work.

 

When I last replaced my thermostat in the end I just removed the complete bleeder screw and filled her up until water came out of the bleeder screw hole.

Just opening it a few turns didn't do it for me. Just used a big enough screw driver that made the screw stick to it.

 

Do the hoses to the radiator get hot eventually?

FYI:

The coolant temperature sensor is located in the thermostat housing, close to the bleed screw. Depending on the variant of your thermostat housing, the sensor is either internal or separately exchangeable.

There is a "hidden menu" in which the temperature reading from the coolant temperature sensor can be selected: