I got my cooling system flushed out at one of my friend's shop today. They let my car sit at idle for almost 10 minutes just to make sure the water temp gauge is ok before letting me take the car out. Now it all seem fine for the first 2 minutes of the drive, then when I was going downhill, the light came on along with the beep. I tried to drive to somewhere where I can pull over and see what's going on, then the light turned off again... and then it just came on and off, on and off. so I finally pulled out into a gas station, turned off the car, unpluged my battery, waited couple minutes, and then start up my car again.... then everything was back to normal. I made it back home without the light coming on again... now is this normal after doing coolant flushes?

 

First of all, you could have a bad sensor. Change the sensor and see if it still goes on and off.
Second of all, if the temperature of the motor keeps on rising and falling, then your choices are as follows:
1. You are building up excess pressure, causing the sensor to go off. Usually, when you build up pressure like this, then you either have a bad rotor housing, or you have a kink in a hose. The only way to fix this is to either get a new rotor housing or just do a complete rebuild.
2. You have a blown hose somewhere. Look on the ground after the car is parked and has been there for a couple of hours. If there is a coolant on the ground, then you do have a blown hose.

If this doesn't work, then take it to a mechanic and let him tell what's wrong with the car.

 

Did you make sure to bleed the air out of the entire cooling system?

 

Sounds like a air bleed problem.
I had to top up my system 3 or 4 times to get the light tio stay off. Topped it up a couple of more times before it stayed full.
Rememer to top up the AST and the fill neck the first couple of times.

 

you will probably need to add more coolant. Happend to me when i flushed mine. Just try to add more coolant and then pump the upper radiator hose, to get the air out.

 

thx guys, I'll try to top it up more... I added some water into the coolant reserve tank, it seems to be fine now, I'm not getting the light anymore...

 

if air is in the system, you need to take the coolant hose off the back of the throttle body and have someone fill it until coolant comes out of the hose, then put it back on and top it off...there ya go

btw the car should be off

 

i alkso think its air in the system, and the air gets to the sensor trippingit on , but be sure to only fill the overflow tank when its WARMED UP, not cold, or else it will dump all over when it warms up and expands

 

definitely air pockets.. like others said.. keep squeezing the main hose and it will get rid of most air.. then let the car run until normal temp.. shut down and let it cool.. then add coolant.. do this couple of times and you should be fine..

I blew my motor on my daily car last year.. luckily it wasn't my 7.. but it was due to poor air bleeding..