2010 Ford Explorer overheating when accelerating, no heat

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2010 Ford Explorer overheating when accelerating, no heat

Unread post by csylvia02 » Sat Dec 06, 2014 6:14 pm

My 2010 Ford Explorer experienced a radiator leak between the radiator and the plastic tank on the top, so I replaced that, we were still not experiencing any heat while driving it. I watched a couple of videos on how to "burp" the system, to no avail.

Next I replaced the thermostat, and "burped" it again, still no heat, so I drained and flushed the system yet again and still no heat. What else is there to check? I have the Haynes manual and did the flush and fill the way the book said and still have no heat I am about to lose my mind.

The blend doors sound like they are opening. They are not clicking like they are broken.

The heater is on full the entire time, I have not rotated the dial since I started this.

I unplugged one of the hoses on the heater core and blew into it, the hose was bone dry and I blew into the end of the hose and fluid came out of the cabin side metal tube. I also plugged a water hose into the tube and ran water through it to make sure it wasn't clogged, it is not. Front and rear heater cores.

Here is everything thing I have done from the start:
Replaced Radiator.
Replaced Thermostat.
Drain and flush and re-service.
Checked for leaks out of the water pump weep hole (none) and operation of pump, the upper hose gets hot and I feel water go through it when the thermostat opens.
Check the radiator cap for pressure, it opens at 20psi and hold between 17-19psi. Replaced radiator cap anyway.
Removed supply hose and ran coolant to help purge trapped air.
Ran water through the supply and return hoses on the heater core. On the front and rear.
Check operation of heater control valve, works.
Turned vehicle on while watching the exhaust pipe, a small amount of water on initial start up in the morning but no smoke.

Problems still occurring:
Drive vehicle it over heats but returns to normal at idle I also get the coolant light that extinguishes when the car returns to idle. Even though it says its overheating the car has not pushed coolant into the expansion tank.
The car will not take any more coolant, and only overheats after the fan comes on. And still no heat.

My background is no car experience, I am a helicopter mechanic and if this was an AH64 I would be done by now. SO please take it easy on a rookie shade tree mechanic.

Should add, 4.0L engine, no oil in water after flush and the engine oil looks like engine oil not milky. Next step was a water pump someone please talk me out of that.

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Re: 2010 Ford Explorer overheating when accelerating, no hea

Unread post by carriedi » Sun Dec 07, 2014 8:30 pm

they make a tool to evacuate the cooling system of air. (Airlift) Snap on tools makes a slightly different version. You empty the cooling system as much as possible, then use the tool to evacuate the air, then you switch a valve and the vacuum in the cooling system pulls the replacement coolant back into the system. Takes out the air pockets that you might get trying to fill from the radiator with coolant already in the system.

The water pump circulates coolant through the engine. When the thermostat is closed the pump still pushes coolant around. It should be circulating to the heater core. (when there is no air in the system) When the engine seems warm (or hot as the case may be) feel the two heater hoses that go to the heater core. Do they both feel hot? does on feel hot and the other one not? do they both feel cold? Things that can cause problems is an air pocket in the heater core. Water pump not circulating enough coolant, (impeller could come loose) This could be why it overheats. A plugged up radiator could also be a reason why the engine overheats while driving but cools down at idle. Restricted flow could be why there is enough cooling at idle but on higher RPM you can't get enough flow through the radiator. But that should make the heater work hotter so I would go back to air pocket or water pump.
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Joined: Wed Dec 31, 2014 8:28 pm

Re: 2010 Ford Explorer overheating when accelerating, no hea

Unread post by dhdishner » Wed Dec 31, 2014 8:36 pm

Get a block testing kit. I am pretty certain you have a blown head gasket or a cracked head. If you have a blown head gasket, make sure to get the heads resurfaced if they are in spec. A lot of times the head will warp if it has been overheated. If the head is too warped, it is best to get new heads. those are all ifs, if the heads are in spec, and are free of cracks, A head gasket with upper gasket set should fix your issue.

** forgot to explain why**
when the head gasket is blown. This forces combustion gasses into the cooling system little by little (or a ton depending on how bad). If it is slight, when you increase engine speed, this raises the compression, which forces air into the cooling system at a higher rate creating an air pocket. This air is far hotter than the coolant so the coolant temp gauge will climb.

In bad cases, you will see a milky substance inside the oil cap, and possibly coolant in the oil. Just drain it and set it aside overnight. It will separate if there is any coolant there. This is because a blown head gasket or cracked head can also suck coolant into the combustion chamber and it will either drain off to the oil, or burn off while driving, or both.

The heater will have issues due to air pockets and what not. But I'm sure you knew that already from chasing the mystery problem.

Don't worry man, a hair crack in the head of a customers car had me about to crack my own head from beating it on the wall. I chased it and chased it and pulled the heads 3 times. Lastly having the heads sent off to a machinist to have it dye tested for cracks. Low and behold. A tiny little f**ker that a tick with a magnifying glass couldn't see.

Hopefully this helps and good luck.

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