My 1997 cadillac eldorado overheats plugs, thermostat, water pump, intake value have been replaced and still over heats.

indicates a blocked radiator cores
not using a thermostat can cause overheating as it allows the movement of coolant to be to fast to allow the transfer of heat from the coolant to the air
the bottom hose will always be cooler than the top hose on a good radiator because of the loss of heat through the fins but if a good cooler then that indicates blockages in the cores

The top radiator hose goes into the thermostat on the top of the engine and the lower comes out of the water pump and returns to the radiator. Hope this helps.

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

are your cooling fans working, do you smell exhaust if you let it rin with the rad cap off if you do its head gaskets if not do you have agood waterpump impellers sometimes go bad

Was the thermostat changed out...Hope this helps.

Engine coolant temperture sensor, This sensor runs the cooling fans. Before that I would check fuses and relays to the fans.
Randy

is the fan coming on? are you losing water out the radiator? if the head gasket is blown it can be blown into the oilpan the oil will be milky it can be leaking out the side of the heaqd at the block or going into the cylinders and out the exhaust you can also have a bad thermostat i have bought bad new ones one way to test it is take it out and boil it in a pan of water it should open about 180 to 190

check engine temp sensor if ok check fan relay

it could be the pump, thermostat, or a bound up heater hose. I would start with a complete power flush, or buy the kit and do it yourself. Then replace the thermostat, if that doesn't work, then have the water pump replaced.

take a look at the hoses on the radiator sometimes they will collapse and stop the flow of water under high rpms