1999 Cadillac Eldorado ,overheating changed thermostat , overflow cap ,no white smoke coming from exhaust.hot blowing from heater

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?

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