Urgent! 2008 Focus 2.0 odd cooling system issue!

Focus 2.0 Duretec. Symptoms, t stat does open, rad fan turns on at correct temp, has strong heat when selected indicating good coolant flow but temp gauge runs hot when heat not on and radiator stays cool under all conditions. As if all coolant flow is being diverted through the heater core and none through the rad. Also, when no heat on there is a coolant leak on the head on the driver side between the machined face and a plastic "hose manifold" bolted to it, has upper rad hose 1 side and a heater hose on the other, but ONLY leaks when no heat is on, no leak when heat is on with engine running, but leaks after shutdown until pressure bleeds off. PLEASE HALP MEEE!!!

Well that is a strange one. Assuming it is full of coolant my first thought is a plugged radiator. Im not real sure how i would go about verifying that though.

Have you tried flushing the radiator?

Also, how old is the radiator cap?

Is there a giant air pocket in the radiator? Is this car a surge-tank car or radiator-cap car?

Since there's a leak for coolant to get out, there's a leak for air to get in.

chaparral wrote: Is there a giant air pocket in the radiator? Is this car a surge-tank car or radiator-cap car? Since there's a leak for coolant to get out, there's a leak for air to get in.

Radiator cap with normal overflow tank. The cap does hold pressure (not sure how much since it is 9 year old OEM, but it definatlely holds pressure). The air pocket thang is interesting, since the leak is about as high up in the system as it can get. My suspicion is, in fact, that leak + cold radiator + hot heater are all caused by the leaky thing in question. Trouble I'm having is that I cannot what this leaky thing is properly called in the Duratec parts nomenclature. By definition it is the upper coolant outlet, but none of the parts I have found match that "name" nor its appearance.

Any Duratec aces around here that can tell me what Ford (and the other parts supply people) call this thing??? I really want a positive I.D. before I start taking things apart.

Top up the system and try again, if the radiator remains cool when the engine's warmed up that means there's a blockage in or near the radiator. Is the hose going to the radiator hot? Be ready to drop the windows and blast the heat if the gauge climbs above normal.

In reply to GameboyRMH:

I did a system cleaning as the first step in dealing with this issue just because, but the old coolant was still really clean on draining, and draining the cleaner out indicated the system wasn't gunked up at all. I think the above mentioned air pocket at the worst possible spot, which gets re-created every time the engine is shut off, makes perfect sense. Now about what the "cylinder head water outlet" is officially called in Duratecese...

Change the radiator cap, too.

The housing on the cylinder head contains the thermostat and heater distribution lines. Its made out of Ford quality plastic.

Go to the Ford store and buy a new one.

Streetwiseguy wrote: The housing on the cylinder head contains the thermostat and heater distribution lines. Its made out of Ford quality plastic. Go to the Ford store and buy a new one.

Are we sure about this? On all other engines I have worked on that is where the t stat is, but my bit of research has the Duratec stat on the block behind the intake manifold, with lower rad hose going into it, and has a reputation for being positively demonic to get at. And none of the photos of what are listed thermostat assemblies are configuredlike the outlet on the cylinder head. So, still a question as to what the cylinder outlet is; is it the thermostat assembly or isnt it???

Is the radiator inlet hose hot to touch? I'm tipping internally blocked radiator, it matches all the symptoms you've described.

daeman wrote: Is the radiator inlet hose hot to touch? I'm tipping internally blocked radiator, it matches all the symptoms you've described.

The upper hose does get some heat, and the radiator fills at a normal rate when adding more fluid. As noted by another member above, it seems the blockage is caused by an air pocket that forms in the upper hose as the system cools, by sucking air at the leak in the coolant outlet or its gasket.

If a dealer is close, walk into the parts dept and, together with the guy behind the counter, you can look at the diagrams on the computer, id the part and order it. Or just id it and order online.

Trend seems to be thermostat in the lower hose instead of the upper.

Went to the Ford Parts site.

Lower radiator hose goes to the thermostat which is on the front side (facing radiator) of the engine.

The fitting on the head which used to house the thermostat is now just a coupling.

OK all leaks are fixed and the system does hold pressure. Now for the rest. After some reflection it seems that the system was slow to both drain and refill. The upper radiator hose gets hot, the lower hose does not and the radiator itself does not get hot. The heater gets blazing hot, and the cooling system maintains proper temperature with the heat on full. I am 90% certain that the above means the radiator is clogged even though I ran a system cleaner through it before beginning work on the leaks. What says the hive, is it time for a new radiator?

Put a hose in the radiator at top (not filler neck) and see if water comes out bottom?

Should be easy to test for a blocked radiator.

Call a radiator shop and compare the rebuild price to a new one. Assuming there is still a radiator shop near you.

Cold radiator can be caused by,

plugged radiator (likely)

No water pump flow (unlikely as there is heater flow)

thermostat not open (possible)

You cannot have any coolant leaks AT ALL!!!!!

Do not run it until this is fixed! Fix this first before you need to pull the head....

I hope its not too late.