2002malibu loosing cooling slowly

What size motor?

B1GG0RK1 - 206 TU ENGINE DW8 ENGINE
DRAINING - FILLING - BLEEDING COOLING SYSTEM
1 - SPECIAL TOOLS
[1] filling cylinder (-).0173/2 .
2 - DRAINING
TU ENGINE
DW8 ENGINE
ALL MODELS
Carefully remove the expansion chamber cap .
Unscrew the radiator drain plug (1) .
NOTE : fit a pipe to the outlet to allow clean drainage of the system .
TU ENGINE
DW8 ENGINE
ALL MODELS
Open the bleed screws (2) .
DW8 ENGINE
Drain the engine by removing the plug (3) .
ALL MODELS
3 - FILLING AND BLEEDING THE SYSTEM
Before any re-filling operation, flush the cooling circuit with clean water .
WARNING : check the cooling system for leaks .
DW8 ENGINE
TU ENGINE
ALL MODELS
Fit the filling cylinder [1] to the filler opening .
Open all the bleed screws .
Fill the circuit slowly with coolant .
Close the bleed screws in the order in which the liquid flows without bubbles .
The filling cylinder must be filled to the 1 litre mark to bleed the heater matrix correctly .
Start the engine .
Maintain the engine speed at 1500 to 2000 rpm until the end of the second cooling cycle (fan(s) starting then stopping) keeping the filling cylinder filled to the 1 litre mark .
Stop the engine .
Remove the filling cylinder [1] .
Immediately tighten the plug on the expansion chamber .
If necessary fill up to the level of the maximum mark (Engine cold) .

Probably the start of a head gasket breech. You can buy a block tester at your local parts store for thirty to forty dollars. Follow the insructions in the box, and it will detect exhaust gasses in your coolant. this is a pretty sure way to detect a combustion to cooling system breech. The cat converter may be masking the white smoke from the coolant once it reaches temp.

OPERATION
The primary purpose of a cooling system is to maintain engine temperature in a range that will provide satisfactory engine performance and emission levels under all expected driving conditions. It also provides hot water (coolant) for heater performance.

Fig. 1 - Cooling System Operation - 2.0L/2.4L 1 - HEATER 2 - HEAT UP 3 - COOL DOWN 4 - PRESSURE CAP 5 - COOLANT OUTLET CONNECTOR 6 - WATER PUMP 7 - ENGINE 8 - COOLANT RECOVERY CONTAINER 9 - RADIATOR

Fig. 2 - Cooling System Operation - 2.7L 1 - HEATER CORE 2 - COOLANT PRESSURE CONTAINER 3 - COOLANT OUTLET CONNECTOR 4 - ENGINE 5 - WATER PUMP 6 - THERMOSTAT 7 - RADIATOR

Hello, you may be right on the money.

How to test the thermostat in most vehicles;

Make sure the heater is off, start the engine and let it run for 6 to 8 minutes, ( this will allow the
engine to reach, " normal operating temperature "), from the inside of the vehicle turn the heater
temperature on high and turn the fan speed on high.
1. Listen very closely for a click sound from the engine, ( most thermostats make a click when
they open )
2. Watch your temperature guage, it should begin to lower as the coolant starts to circulate.
3. Usually within a few minutes the radiator fan will kick.

What the thermostat does;

It seperates your coolant into two parts. The first part is in your engine, the second part is in your
radiator and the coolant reservior. When the coolant in the engine reaches the temperature rating
on the thermostat the thermostat opens to allow the two parts of coolant to change places. Now
the cooled coolant in the radiator and reservior flows into the engine while the heated coolant flows
from the engine into the radiator and reservior to be air cooled by the radiator fan.

I hope this helps you.

The most likely causes of a hot running engine are the following:

1. low antifreeze level in the radiator and cooling system.
2. fan not turning on at operating temperature.
3. restrictions in the cooling system such as sediment build up.

Water pumps usually leak when they are bad, and can cause an overheat because of low coolant level.
Check whether the water pump is leaking after topping off the coolant level and running at operating temperature, and then shutting off the car's engine.

These cars have a hydraulic cooling fan, and they can go bad.
The usual potential cooling problems apply, and the crazy hydralic drive just makes it more complicated. An electric fan is good or bad, but a hydralic fan can slowly loose the ability to spin fast enought to get the job done

1 quart of coolant per cylinder
6 quarts of coolant 6 quarts of water 50/50 mix

When engine is cold, remove the bottom radiator hose from the radiator and let all fluid drain into a bucket.
Replace hose and refill cooling system with desired inhibitor/coolant mix.

Chris I would get the coolant system pressure tested and it might show up the problem