I have a 2002 cadillac dhs and the check coolant level comes on. why is this happening. I had the system flushed and it still comes on. Also, my check system stablilizer comes on also. Please, I do need some assistance with this. Thank you!!

There are a lot of coolant lines around the Northstar engine, but not one called a "purge line" that I am aware of. The coolant system is designed to be a closed system, and is never purged.

However, there is a rubber drain line on the pressurized overflow tank that will release coolant on excessive pressure sensed by the rad cap on the tank, or if the rad cap is faulty. If the system has a leak anywhere, it will not hold required pressure and that will always cause overheating. If you are losing coolant, that is the first place to look (bad rad cap, or cracked tank or line from the tank to the rad).

You may have air in tyhe system and when you rev the engine the level drops enough to set the light off. Try bleeding the system or have it pressure bled at a radiator shop.

CHECK HEAD GASKET.... COULD BE CRACKED BLOCK

THE CADILLAC HAS A COOLING SYSTEM THAT IS A LITTLE COMPLICATED.. YOU HAVE TO FOLLOW THE HOSES AND CHECK FOR LEAKS.. BUT THAT CAN ALSO BE FROM A SEAL ON THE ENGINE. THEY ARE CALLED. FREEZE PLUGS. THOSE CAN ALSO LEAK.. A HOSE, NEAR THE RIGHS,WATER PUMP OR FREEZE PLUG. THAT IS ALL.

WAIT UNTIL YOUR ENGINE IS COLD,YOUR RADIATOR PRESSURE CAP IS LOCATED ON THE COOLANT OVER FLOW RESERVOIR, THATS WHERE YOU ADD COOLANT WHEN COOLANT LOW,YOU POUR COOLANT IN THE OVER FLOW RESERVOIR UNTIL COOLANT LEVEL REMAIN AT FULL COLD MARK DONT OVER FILL OVER FLOW RESERVOIR, WHEN COOLANT LEVEL STOP DROPPING WHEN ADDING COOLANT AND COOLANT LEVEL STAY AT COLD MARK ON THE RESERVOIR YOU RADIATOR HAS THE CORRECT COOLANT LEVEL IF COOLANT LEVEL KEEP DROPPING CHECK FOR COOLANT LEAKS AROUND RADIATOR AND THE TOP AND BOTTOM RADIATOR HOSES, LOOK FOR COOLANT LEAK AT WATER PUMP GASKET OR SEAL OR LEAK AT WATER PUMP WEEP HOLE IF YES REPLACE WATER PUMP.

Check your water level. If coolant is fine, then you might have to change your thermostat. Also your waterpump might be getting weak. When a water pump goes bad, there are bore holes that will leak, have you noticed any coolant on the ground or under the hood? If so where? Sometimes the thermostat starts sticking as the vehicle gets older, or a higher temp thermostat is installed. If this happens, like low coolant, the car has to run to a certain temp before the fan comes on to cool it. If you check all that and it still does the same thing, flush your cooling system. If you check all of this and still have a problem, let me know and I will help you fix it. Hope this helps

Why replace the radiator it's just a bad sensor. Get the Haynes repair manual on your vehicle look up the water level sensor testing and replacement steps. The sensor probably cost around $30 and I doubt if it takes more than 30 minutes to replace.

The most common overheating problem with the Northstar engine is a blocked purge line. It's job is to purge air out of the cooling system.
There is a small diameter hose coming from near the top of the coolant tank,this is the purge line.
With the engine idling,pull the purge line from the tank,if there is no coolant flow from this small hose,it is blocked and this will cause overheating.If the hose is clear, check for blockage at the nipple on the tank.Or trace the hose back until you find the blockage.The hose goes in to the engine to a crossover and comes out the other side to near the thermostat housing,the blockage may be there.

The most common overheating problem with the Northstar engine is a blocked purge line. It's job is to purge air out of the cooling system.
There is a small diameter hose coming from near the top of the coolant tank,this is the purge line.
With the engine idling,pull the purge line from the tank,if there is no coolant flow from this small hose,it is blocked and this will cause overheating.If the hose is clear, check for blockage at the nipple on the tank.Or trace the hose back until you find the blockage.The hose goes in to the engine to a crossover and comes out the other side to near the thermostat housing,the blockage may be there.

1. Check the level you filled the coolant to...If you overfilled it this will happen. 2.  Did you add the correctly diluted antifreeze? 3. Check to be sure the radiator is unobstructed