Cooling system our cooling system is going crazy. we have replaced everything on entire line. this includes radiator,water pump,thermostat,all sensors associated with heating and cooling but coolant will not circulate through the engine and fans will not kick on.temp. indicator reads hot but you can put your finger in the radiator and it's not even hot.

flushing a cooling system is the same method as any other motor

do it without the thermostat fitted
or water pump opening

sacrifice an old radiator hose to adapt a garden hose fitting
for radiator flush

air in system fix
your thermostat housing has no air bleed valve
no top radiator cap

old school way
heater on full
run motor till thermostats fully open
burp radiator hoses
wait till water is running up into over flow bottle without bubble
replace cap
turn off heater
correct level in over flow bottle

why still over heating
you fitted everything i would have ... yet still overheat
possibles
leaking inlet manifold gaskets
hose clamps loose
cooling fans spinning too slow
thermostatic fan switch faulty
aluminum radiator is a big one
air ..fins bent or some water channels blocked

or possible head gasket leak

Are the cooling fans coming on ? Go under the hood in the engine compartment , with the vehicle running have some one turn on the A/C , do you see and or hear the cooling fans come on ? Could be the coolant temperature gauge is bad ! How many miles on the vehicle ? Ever have water pump replaced ?

1

Check for a loss of system pressure.
Is there a loss of system pressure?
--
Go to Step 2 yes
Go to Step 3 no

2

Inspect and repair any faulty hose connections.
Does the engine still overheat?
--
Go to Step 3 yes
System OK

3

Check for low coolant protection (-37?°C/-34?°F).
Is there low coolant protection (-37?°C/-34?°F)?
--
Go to Step 4 yes
Go to Step 5 no

4

Test solution. Replace the coolant if necessary.
Does the engine still overheat?
--
Go to Step 5 yes
System OK

5

Check the water pump belt for low tension.
Is the water pump belt tension too low?
--
Go to Step 6 yes
Go to Step 7 no

6

Replace the water pump belt tensioner.
Does the engine still overheat?
--
Go to Step 7 yes
System OK

7

Check for an inoperative thermostat bypass.
Is the thermostat bypass inoperative?
--
Go to Step 8 yes
Go to Step 9 no

8

Replace the bypass.
Does the engine still overheat?
--
Go to Step 9 yes
System OK

9

Check the water pump.
Is the water pump inoperative?
--
Go to Step 10 yes
Go to Step 11 no

10

Replace the water pump.
Does the engine still overheat?
--
Go to Step 11 yes
System OK

11

Check the radiator fins for obstruction.
Are the radiator fins obstructed?
--
Go to Step 12 yes
Go to Step 13 no

12

Inspect and clean the radiator fans.
Does the engine still overheat?
--
Go to Step 13 yes
System OK

13

Check the cooling system passage for obstruction.
Is the cooling system passage blocked?
--
Go to Step 14 yes
Go to Step 15 no

14

Inspect and flush the system. Reroute or replace the hose if necessary.
Does the engine still overheat?
--
Go to Step 15 yes
System OK

15

Check the water pump belt for damage.
Is the water pump belt damaged?
--
Go to Step 16 yes
Go to Step 17 no

16

Replace the water pump belt.
Does the engine still overheat?
--
Go to step 17 yes
System OK

17

Check the cooling fans.
Are the cooling fans inoperative?
--
Go to Step 18 yes
Go to Step 19 no

18

1. Inspect the electrical connector. Replace if necessary.
2. Does the engine still overheat?

--
Go to Step 19 yes
System OK

19

Check the throttle body circuit flow.
Is the throttle body circuit flow restricted?
--
Go to Step 20
Go to Step 21

20

1. Inspect the orifice and associated hose. Replace if necessary.
2. Does the engine still overheat?

--
Go to Step 21
System OK

21

Check for a stuck thermostat.
Is the thermostat stuck in the closed position?
--
Go to Step 22
--

22

Replace the thermostat.
Does the engine still overheat?
--
--
System OK

Also.........

Best Practices

• To prevent an expensive, recurring problem, the integrity of the entire cooling system should be inspected and tested when a head gasket is replaced.
• During this repair, the cylinder head(s) will need to be inspected and machined. Additional repairs may be needed after the inspection, which can add several hundred dollars to the repair and are not included in the RepairPal estimate.
• Cylinder head gasket replacement often occurs when the engine has high mileage; several additional parts may be needed during the repair. These may include cooling system components (hoses, water pump, radiator, thermostat, etc.) vacuum lines, timing belt, ignition wires, and more. These will be in addition to the RepairPal estimate above.

If everything including the water pump and thermostat has been replaced, you are looking at something other than the cooling system.
Has it been running hot since the engine was rebuilt ? Is the exhaust in good condition ?
How long can you drive it before it overheats, and does the gauge show it hot, and does it boil over ?

Unfortunately, you can't replace the thermostat by itself. It is part of an overall assembly which includes the waterpump. Below are the instructions:

• Drain the cooling system to a level below the thermostat.
  
• Remove the radiator outlet hose.
  
• Remove the water pump inlet bolts.
  
• Remove the water pump inlet and thermostat from the water pump.
  

To install:

• Install the thermostat and thermostat housing to the water pump.
  
• Install the thermostat housing bolts. Tighten the bolts to 11 ft. lbs. (15 Nm).
  
• Install the radiator outlet hose.
  
• Properly fill the engine cooling system and check for leaks.
  

CHECK COOLANT LEVEL MOST NEWER VECHICLE DONT HAVE RADIATOR CAP YOU HAVE TO POUR COOLANT IN THE COOLANT OVERFLOW JUG THE COOLANT WILL GO TO RADIATOR. IF THE COOLANT OVERFLOW JUG EMPTY ADD COOLANT UNTIL COOLANT LEVEL STOP DROPPING AT STAY AT FULL COLD MARK.IF COOLANT OKAY,NEED TO REPLACE THERMOSTAT AND COOLANT OVERFLOW JUG PRESSURE CAP. IF ALL BEEN DONE. MOST OF THE TIME WHEN CAR OVERHEATING WHILE MOVING. RADIATOR CORES STOPPED UP OR RADIATOR GRILLE DIRTY OR RESRICTED.ENGINE BLOCK COOLANT PASSAGES CLOGGED AND HEATER CORE CLOGGED.CHECK WATER PUMP SEE IF WATER PUMP WEEP HOLE LEAKING IF SO REPLACE WATER PUMP.IF ENGINE OVERHEATING AT A LONG TRAFFIC LINE ENGINE COOLING FANS NOT RUNNING EITHER COOLING FANS FUSE AND RELAYS BAD.OR ENGINE COOLANT TEMPERATURE BAD. THE ENGINE COOLANT TEMPERATURE SENSOR TURNS ON COOLING FANS AT A CERTAIN TEMPERATURE IF SENSOR BAD FANS WONT TURN ON. MAKE SURE YOU HAVE 50 /50 MIXTURE OF COOLANT AND WATER IN COOLING SYSTEM.

the cooling systems consists of a radiator, radiator cap, water pump, thermostat, hoses, heater core and sometime a heater control valve that open water lines to heater core. You may need a cooling system flush if water pump, radiator have been replaced. flush the system.change the thermostat and have the heater core checked too if you can get to it.
does the cooling fan kick on to cool the radiator..check that too.replace radiator cap and check cooling fan yourself...let me know if need anything else.
Thanks for using fixya and please vote.

Are you sure you burped the system of all air? Air in the system can stop the thermostat from opening and cause it to overheat.

is it an electric fan? check connections,fuses,relays, temp. sensor all of these xould be the problem.

you probably have air trapped in the system. Have dealer or radiator shop bleed system.

I assume your cooling fan is working.

what engine v6 or v8?

SECTION 303-03: Engine Cooling 2001 Lincoln LS Workshop Manual
DESCRIPTION AND OPERATION Engine Cooling The cooling system components include the:

• block heater (optional)
• cylinder head temperature sensor
• fan blade, fan motor and fan shroud assembly
• radiator
• pressure relief cap
• degas bottle
• radiator draincock
• water pump
• oil cooler (optional)
• water thermostat

The water thermostat:

• controls the engine coolant temperature.
• allows quicker engine warm-up.

The degas bottle:

• provides a location for system fill.
• contains coolant expansion and system pressurization.
• provides air separation during operation.
• replenishes the engine coolant to the system.

The fan blade draws air through the radiator to help cool the engine coolant.
The fan motor:

• operates only when the engine is running.
• will not operate when the engine is off.

The engine coolant flows:

• from the lower radiator hose to the water pump.
• from the water pump to the engine block and the cylinder heads.

A closed water thermostat returns the engine coolant to the water pump. An open water thermostat allows the engine coolant to flow to the radiator.
Unsatisfactory coolant materials:

• Alcohol-type antifreeze does not provide adequate water pump lubrication.
  • has lower boiling point
  • reduced antifreeze protection
• Alkaline brine solutions will cause serious engine cooling system damage.

The cylinder head temperature sensor provides a signal to the temperature gauge.

• will invoke failsafe cooling.

The optional block heater:

• electrical heating element is installed in the block cooling jacket.
  • uses a standard 110V (220V in Europe) electrical supply
• keeps the engine coolant warm during cold weather.

The auxiliary water pump (3.9L only):

• provides heater coolant flow boost.
• has a secondary function of providing engine-off cooling.