Coolant level low, guage reads over heating, i replaced the water pump and thermostat it didn't solve the problem. upper radiator hose very seldomly hot. what else can i do?

most likely air in the colant system, an air bubble trapped when water pump was replaced. An eazy way to tell if air is in the coolant system squeze the upper radiator hose, if seems empty or can hear coolant swishing around, then there is air in the coolant system and also coolant level not compmetely topped off.

Top off coolant with Antifreeze Concentrate, NOT WATER. water will boil and evaporate, 50/50 antifreeze mix is good but if you dont know how much water has allready been added to the coolant system then straight shots of Antifreeze is recommended when toppong off coolant level.

Remove Air and Top Off Coolant

•While Engine is cool
•Remove radiator cap
•Slowly fill to the rim with Antifreeze, while at the same time squeezing the upper radiator hose to swoosh around coolant, try to get as full as you can.
•Replace Radiator Cap
•Start engine and switch air fan on high
•Remove radiator cap
•Squeez upper radiator hose and add more Antifreeze as Nessesary
•Notice preasure on the coolant hose, while adding antifreeze Concentrate preasure on the hose will stiffin up,
When coolant is full turn off the motor.

Removal & Installation

• 4.6L & 5.4L SOHC ENGINES
• 5.4L & 6.8L ENGINES
• 5.4L DOHC ENGINE
• 6.0L DIESEL ENGINE

Print

4.6L & 5.4L SOHC Engines

1. Partially drain the engine cooling system to a level below the thermostat.
2. Disconnect the upper radiator hose from the water outlet adapter.
3. Remove the power steering reservoir upper mounting bracket.
4. Remove the bolts and remove the water outlet adapter.
5. Remove the water thermostat and the O-ring seal. Discard the O-ring seal.
6. Installation is the reverse of the removal procedure. Tighten the water outlet adapter bolts to 18 ft. lbs. (25 Nm). Tighten the power steering reservoir upper mounting bracket as shown in the accompanying illustration.
   
   

   Fig. View of the power steering reservoir upper mounting bracket and tightening specifications
   
   
   

   Fig. Exploded view of the water outlet adapter and tightening specifications
   

5.4L & 6.8L Engines

1. Partially drain the cooling system to a level below the thermostat.
2. Disconnect the upper radiator hose.
3. Remove the coolant outlet connection, as follows:
   1. Remove the bolts.
   2. Remove the coolant outlet connection.
   
   
4. Remove the (A) coolant thermostat and the (B) O-ring seal.
5. Discard the (B) O-ring seal.
   
   

   Fig. Remove the (A) coolant thermostat and the (B) O-ring seal
   

To install:

NOTE Thermostat must be installed as illustrated.

1. Use a new (A) O-ring seal to position the (B) coolant thermostat in the (C) upper intake manifold.
   
   

   Fig. Use a new (A) O-ring seal to position the (B) coolant thermostat in the (C) upper intake manifold
   

2. Install the coolant outlet connection, as follows:
   1. Position the coolant outlet connection on the upper intake manifold.
   2. Install the bolts and tighten to 15-22 ft. lbs. (20-30 Nm).
   
   
3. Connect the upper radiator hose.
4. Fill the cooling system.

1. Before servicing the vehicle, refer to the precautions section.
2. Partially drain the cooling system to a level below the thermostat.
3. Disconnect the upper radiator hose.
4. Remove the coolant outlet connection, as follows:
   1. Remove the bolts.
   2. Remove the coolant outlet connection.
   
   
5. Remove the (A) coolant thermostat and the (B) O-ring seal.
6. Discard the (B) O-ring seal.
   
   

   Fig. Remove the (A) coolant thermostat and the (B) O-ring seal
   

To install:

NOTE Thermostat must be installed as illustrated.

1. Use a new (A) O-ring seal to position the (B) coolant thermostat in the (C) upper intake manifold.
   
   

   Fig. Use a new (A) O-ring seal to position the (B) coolant thermostat in the (C) upper intake manifold
   

2. Install the coolant outlet connection, as follows:
   1. Position the coolant outlet connection on the upper intake manifold.
   2. Install the bolts and tighten to 15-22 ft. lbs. (20-30 Nm).
   
   
3. Connect the upper radiator hose.
4. Fill the cooling system.

5.4L DOHC Engine

1. Partially drain the engine cooling system to a level below the thermostat.
2. Disconnect the upper radiator hose, the heater water inlet hose and the heated PCV inlet hose from the water outlet adapter.
   
   

   Fig. Disconnect the upper radiator hose, the heater water inlet hose and the heated PCV inlet hose from the water outlet adapter
   

3. Remove the water hose connection and thermostat.
4. Installation is the reverse of the removal procedure. Tighten the mounting bolt to 18 ft. lbs. (25 Nm).
   
   

   Fig. Exploded view of the thermostat-5.4L DOHC engine
   

I would bet the water pump is either siezed or the impeller (which is plastic) is broken. One thing you can do is let the engine run until the temp guage reads in the normal position. Feel the upper and lower hoses. If one is hot and the other is cold than there is no coolant flow. If the thermostat where the problem than there would still be heat since the water pump is still working. If there was heat before you changed the thermostat and know there is no heat than you have air in the system and it needs to be purged. You can do this by removing the radiator cap on a cold engine. Top off the coolant as necessary. Start the engine. Continue to monitor the coolant level and add as needed. Let the engine warm up until the fans come on. Replace the radiator cap and you should be good to go. Let me know if you have any questions and I'll do my best to answer them. Thank you for using FixYa.com!

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

CHECK ENGINE COOLANT LEVEL.MAKE SURE COOLANT OVER FLOW JUG HAS COOLANT IN FULL COLD MARK.IF COOLANT OVER FLOW JUG IS EMPTY RADIATOR GOT TO BE LOW ON COOLANT POUR COOLANT IN THE OVER FLOW UNTIL COOLANT LEVEL STAY AT THE COLD FULL MARK.SEE IF RADIATOR DONT HAVE A RADIATOR CAP YOU HAVE TO POUR COOLANT IN THE OVER FLOW JUG COOLANT WILL FLOW DOWN IN RADIATOR UNTIL COOLANT LEVEL STOP AT FULL COLD MARK.IF COOLANT LEVEL OKAY.YOUR THERMOSTAT NEED CHANGING ALSO RADIATOR PRESSURE CAP.HAVE RADIATOR FLUSHED OUT.HAVE ENGINE BLOCK FLUSHED OUT.CHECK ENGINE OIL IF OIL LOOK LIKE MILK SHAKE ON OIL DIP STICK YOU HAVE LEAKING HEAD GASKET THAT WILL CAUSE ENGINE OVER HEAT WHILE CAR IN MOTION.CHECK WATER PUMP MAKE SURE ITS WEEP HOLE NOT LEAKING ANTIFREEZE IF SO WATER PUMP NEED REPLACING.

Your Ranger is 19 years old. You need to perform a complete cooling system service. Drain the coolant and flush the system with a commercial flush as directed on the can. Make sure the heater is set to hot. Replace the thermostat. On your Ranger it is difficult to access as it is hidden down low on the engine where the upper radiator hose connects to the engine. Refill it with a 50/50 mix of antifreeze and distilled water. While performing this service inspect and replace any hoses that are suspect.

Now that you've eliminated the thermostat, it could be a number of other things. Don't drive the car too far until you've fixed the overheating problem - overheating can destroy an engine.

That split ribbed hose you see is plastic wire loom - it carries and protects electrical wires, and is not the cause of overheating.

1. Low coolant level
2. Radiator hose split/cracked, causing low coolant level.
3. Head Gasket - leaking, causing low coolant level
4. Thermostat - stuck closed (you eliminated this possibility)
5. Radiator cap - worn/damaged
6. Radiator fins - obstructed by debris/cardboard
7. Water Pump belt - missing/broken
8. Heater Core - leaking, causing low coolant level
9. Intake Manifold Gasket - leaking, worn, damaged
10. Radiator Fan Relay - faulty
11. Radiator Fan Blade - broken, missing
12. Radiator Fan Sensor/Switch - faulty
13. Water Pump - leaking, causing low coolant level
14. Radiator Fan Motor - faulty

My primary suspects would be Rad Fan Relay (#10), and
Rad Fan Switch (#12).

I would probably start by replacing the upper hose. The temperature guage and heat will be affected by poor circulation of coolant.

Hi there,

Firstly - DO NOT run engine, when guage reads hot, as this will cause costly damage to head gasket & alloy engine head.

The fact that guage takes 1min to read HOT, would confirm the guage IS working properly.

So, other components which are likely to cause hot readings (in this order) are:

- lack of coolant (or leakage somewhere): is there sufficient green coolant at the correct level? Top up mixture to correct level. Repair any leaks.

- collapsed radiator hose: when engine is cold, start engine, then quickly watch both upper & lower radiator hoses to see if either begins to flex inwards (collapse). Replace if either hose is collapsed.

- bad/incorrect thermostat rating : when replacing thermostats, you must ensure it is of the SAME temp rating (they all differ).

- Incorrect Temp sensor rating: the ratings of this sensor must be within manufacturer's spec's.

- bad waterpump: the engine relies on the waterpump to distribute the coolant throughout the entire system. If waterpump is faulty, coolant will not flow quick enough, causing overheating.

If you still believe all of the above components are OK, then have your cooling system "pressure tested". This test should be done, before looking further at other electrical components.

Cheers,

"if this has helped you in any way, please rate this solution"

Check coolant level when cool. Make sure cooling fan at rad is working, and then I'd change thermostat.

This could be a multitude of things:

Stuck closed thermostat.

Cooling fan not coming on.

Clogged radiator.

Low on coolant.

Water pump failing/leaking.

Head gasket blown, leaking exhaust into antifreeze.

Clogged catalytic converter.

Thermostat: If the Van heats up, then feel the upper radiator hose. If it's cold, then your thermostat is closed. Replace thermostat.

Coolant: If low, simply fill with distilled water and coolant. Low levels will let engine over heat.

Radiator: If there are cold-to-the-touch spots on the radiator after it should be warmed up, then a clogged is probably occuring. Have radiator flushed.

Head Gasket: If you smell exhaust fumes in your coolant reservois tank, then you got a blown head gasket.

Cat Converter: Only can be tested if off the car. Or you could try a non-contact thermometer. These are also good to testing cold spot on radiator or if thermostats are open.

Cooling fan: If mechanical it'll be spinning. If electrical, it should come on automatically with the A/C, or when it gets hot.

Water pump: Will be leaking from the front if it needs replaced. On a van, it's a tough job.

Good luck!