Tips on Bleeding the 2.3L Coolant

One of the problems with the Ford 2.3L engine is air trapped inside the coolant system especially the heater hoses. If air is trapped inside the coolant lines, then the coolant will not flow. The air will actually block the coolant flow. Two symptons will occur:

  • Engine Overheating - air will usually be trapped in the head and cause overheating of the engine or the engine will run hot. I've even seen some strange cycling of the temperature gauge where the temperature gauge climbs rapidly and then drops quickly like a windshield wiper! Checking the radiator level usually indicates low coolant level.

  • No heat from Heater - No hot air coming from the in car heater even if the engine is warmed up. This indicates that there is an air lock in the heater hose. This is the most common air lock in the coolant system. Checking the radiator level still indicates a full level of coolant.

Bleeding the system!

Do NOT attempt this with a warm or hot engine. The coolant will be scalding/burning HOT and under pressure. If you release the radiator cap, you may be severely BURNT! With the engine cold and on a level surface:

  1. Release the any pressure from the radiator by slowly turning the radiator cap to open it.
  2. Top off the coolant level in the radiator with an appropriate coolant
  3. Slowly squeeze the upper and lower radiator hoses (big hoses) to remove any air trapped inside - add coolant if necessary
  4. With the radiator cap removed, start and run the engine at idle for 5 minutes. This will help release any air trapped in the system - add coolant if necessary
  5. Here's the trick: remove a heater hose from the firewall, raise the end and pour coolant into the hose end until coolant trickles out of the hose fitting in the firewall.

    Remove heater hose from firewall and add coolant as per instructions

  6. Connect the heater hose back up and top off the coolant reservoir to the cold level

Your engine should now be properly bled with no air trapped in the system!

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Copyright February 2011 Eugene Blanchard