2004 Ford Explorer Q&A

2004 Ford Explorer Question: My 2004 Ford Explorer 4.0V6 overheating,Is there a Definite Fix?Intake/T/housing

I have read a lot of blogs in other Forums. My 2004 Ford Explorer has the 4.0 V6 Flex Fuel Engine. The 8th digit of the vin is "K". I replaced the Whole Thermostat housing including new t-stat and gasket. The part came with o-ring for under t-stat housing to engine,which was already installed.Also had t-stat & t-stat gasket and a small o-ring I believe is a new one for the Temp sensor that goes in top of t-stat housing.I have only one sensor so I used the plug(came w/ housing)for the other hole.Followed Coolant bleeding instructions from Chilton Repair Manual exactly as it explained.Now, The temp will stay Normal around town but as soon as I go on the Highway the needle shoots up to Hot.The check gauge comes on and the coolant is boiling in the coolant Tank!T-stat does open and Top hose gets Hot. Also idles like crap which it did not do before.I don't like the No radiator cap design!I have tried everything. I know the way the coolant system works that is why this is confusing!It doesn't make sense the way that it overheats.If I let it sit at idle, there are no problems.The needle stays in the middle were it is suppose to be. Any help would be appreciated. -
Answer 1
Since you have correctly installed stat and purged all air...Possible radiator restriction. Also suggest getting a combustion leak test performed If you want to know, for sure, if you have a head/gasket problem!!! Check coolant level before starting engine in the morning, or while engine is cold, to see if more is needed. -
Comment 1
Pushrod & Goodguy, I am still being challenged by this Ford!I have done a lil more since Ive posted last.I have flushed system FULLY(even taking off each hose to make sure no clogs).Replaced Coolant Tank CAP(No Radiator Cap).Removed PLASTIC INTAKE(Poor Design)& replaced Lower Intake Gaskets.Put it all back together,double checking Everything I unplugged or took off or disconnected.Filled Coolant System with correct 50/50 coolant.Said a little Prayer and Turned the Key!It Started right up,No Problem.The next morning I came out to check coolant tank,almost empty.WTF?So I filled tank & drove around.Once it heated up,the needle would float a lil bit till it finally went all the way to HOT & the check gauge light came on.Turned motor off Immediately.I tightened Intake bolts again after the motor cooled down.Nothing is Leaking But I think the coolant must be going out the exhaust when i'm driving.I see white smoke once in awhile not a lot & it goes away.Also SOMETIMES it has erratic idle/hesitation.When thats not happening it runs great. Smooth like it's suppose to.Any Help would be appreciated.My best educated guess is I have a cracked valve.By the way I did a coolant pressure test & it held at 16psi.That should of found LEAK if there was one....correct?Also the cooling fan is working correctly. -
Comment 2
COMBUSTION LEAK TEST NEEDED!! Any repair shop SHOULD be able to do it. -
Answer 2
does it have an electric cooling fan if so is it working if no fan then I agree with pushrod and check for a head gasket problem -
Comment 1
Pushrod & Goodguy, I am still being challenged by this Ford!I have done a lil more since Ive posted last.I have flushed system FULLY(even taking off each hose to make sure no clogs).Replaced Coolant Tank CAP(No Radiator Cap).Removed PLASTIC INTAKE(Poor Design)& replaced Lower Intake Gaskets.Put it all back together,double checking Everything I unplugged or took off or disconnected.Filled Coolant System with correct 50/50 coolant.Said a little Prayer and Turned the Key!It Started right up,No Problem.The next morning I came out to check coolant tank,almost empty.WTF?So I filled tank & drove around.Once it heated up,the needle would float a lil bit till it finally went all the way to HOT & the check gauge light came on.Turned motor off Immediately.I tightened Intake bolts again after the motor cooled down.Nothing is Leaking But I think the coolant must be going out the exhaust when i'm driving.I see white smoke once in awhile not a lot & it goes away.Also SOMETIMES it has erratic idle/hesitation.When thats not happening it runs great. Smooth like it's suppose to.Any Help would be appreciated.My best educated guess is I have a cracked valve.By the way I did a coolant pressure test & it held at 16psi.That should of found LEAK if there was one....correct?Also the Cooling Fan is Working Correctly. -