Expert: Roland Finston - 10/26/2011

Question
I just purchased a used 2004 chrysler concorde. It is slightly overheating & seems to be losing coolant. I purchased the car from a auction in birmingham,al, but I live in anniston,al;which is about a 70 mile trip.I drove the car about 15 to 20 miles before I had to stop for gas, it was then that I noticed some steam coming from under the hood. So I checked up under it&there was no coolant in the reservoir @ all. We put some water in it until I could make it to get some antifreeze. I made a couple of stops in case the car needed time to cool down until I got home so my dad could put the coolant in it. The temp gauge never would only hit slightly above 1/4 mark the whole time. After the coolant was added the car drove fine. Then the next day I noticed it started getting hot again. It was then I noticed a rushing sound ,like water ruching,coming from within the vents when I cut the car off. My dad checked the coolant again & it was low, but I haven't seen any leakage yet. Could possibly know what would be causing this problem?

Answer
Hi Erica,
The rushing sound from the vents may be indicative of a coolant leak in the HVAC heater core under the dash. Check to see if the floor mats under it are wet. Another possible cause of coolant loss is a head gasket leak which would be shown by there being excessive white smoke from the tail pipe when first starting the engine from cold. If neither of those are present, then I would check that the system doesn't have air trapped in it.
The other aspect of this car is that you have to refill the cooling system in a specific way to avoid having air bubbles trapped in the system.  Chrysler advises the use of a special funnel with an accessory hose clip, Miller part no. 8195.
Here is how to do it:
You might want to start by draining off and collecting for re-use some coolant from the radiator so as to begin with a partially filled system. Close the radiator draincock by turning it to the 3 o'clock position.
Open cooling system 'bleed valve'. This valve is located on the lower intake manifold at the front of the engine, left of center. Look for the valve near the spark coil for the #2 cylinder, looking down from above in the open space between the outer wide portion of the upper manifold and the pipe that inlets intake air to the #2 cylinder.
Attach a 6.35 mm (0.250 in.) inside diameter clear hose that is 120.0 cm (48 in.) long to the bleed valve. Route the hose away from accessory drive belts and radiator fan. Position the other end of hose into a collecting container. The hose will prevent coolant from contacting accessory drive belts and other components.
Remove cooling system pressure cap. Attach Special Tool 8195, Filling Aid Funnel to coolant pressure container filler neck. This funnel has a septum that splits into a wider and narrower opening.
Use the supplied clip to pinch overflow hose that connects between the two chambers of the pressure container
Pour coolant into the larger section of Filling Aid Funnel (the smaller section of funnel is to allow air to escape).
Slowly continue filling until a steady stream of coolant flows from attached hose on bleed valve.
Close bleed valve and continue filling system to top of Filling Aid Funnel. DO NOT overtighten. TIghten to 12.4 N·m (110 lbs. in.).
Remove clip from overflow hose.
Allow coolant in Filling Aid Funnel to drain into overflow chamber of pressure container.
Remove Special Tool 8195, Filling Aid Funnel and install pressure cap on pressure container.
Remove hose from bleed valve.
Start engine and allow to run until thermostat opens and radiator fans cycle.
NOTE:

The engine cooling system will push any remaining air into the pressure container within about one half hour of normal driving. As a result, a drop in coolant level in the pressure container may occur.

If the engine cooling system overheats and pushes coolant into the overflow chamber of the pressure container, this coolant will be sucked back into the cooling system ONLY IF THE PRESSURE CAP IS LEFT ON THE PRESSURE CONTAINER. Removing the pressure cap breaks the vacuum path between the two chambers of the pressure container and the coolant will not return to the cooling system.


Shut off engine and allow it to cool down. This permits coolant to be drawn into the pressure chamber.
With engine COLD, observe coolant level in pressure chamber. Coolant level should be within MIN and MAX marks. Adjust coolant level as necessary.

The coolant bottle has two chambers. Coolant will normally only be in the inboard (smaller) of the two. The outboard chamber is only to recover coolant in the event of an overheat or after a recent service fill. The outboard chamber should normally be empty. If there is coolant in the overflow side or the coolant bottle (after several cold/warm cycles of the engine) and coolant level is within the min/max marks, disconnect the overflow hose at the filler neck and lower it into a clean container. Allow coolant to drain into the container until emptied. Reconnect hose to filler neck.    
Roland
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