2006 Explorer 4.0 Cooling System Issue

[axelofc69]

Im trying to figure out what the hell is going on with this vehicl.
I have a 2006 Explorer Ltd. 4.0 I bout a few years back with 47k mi. Currently 113k.The vehicle was trouble free up until 2 years back.
The thermostat housing developed al crack and leaked all of the coolant out on highway when my wife was driving. Fortunately it was close to my brothers and was able to park there and do the repair.It was fine up until about novemeber when the radiator developed a leak. Replaced with a nice new radiator.

Since then it will on occasion I guess overheat. The needle will go up and red coolant warning flashes. You can hear fan roar and then goes down. It will do this cold or hot. Sometimes the need will remain normal and fan roars.
It will push coolant into expansion tank.
So I replaced the thermostat for the hell of it. Nothing...
Then I had the cooling system flushed. A little better, but now back to the same.

Any ideas of what can be going on? Bad fan clutch? Bad water pump?? Im stumped. Its not leaking anywhere either. Obviously holding pressure as I didnt let cool down and pulled out sensor in housing to check and let off pressure and hot coolant.

im sure someone here has had same issues. Trying to fix myself before I take to Stealership or just finally get rid of it.

Input would be appreciated.

 

[Tech By Trade]

Waterpump could be on the way out? Bet the fins are gone or going.

 

[axelofc69]

Waterpump could be on the way out? Bet the fins are gone or going.

Do you really think water pump? its over heated several times over last couple of years with all of the cooling system issues that I fear its damn blown head gaskets. Although no exhaust steam or milky oil. I took radiator cap off after topping up yesterday. I started up and when i revved motor coolant would pop up. Wouldnt that indicate blown head gasket?

 

[Tech By Trade]

Bubbles when the system is pressurized would indicate a blown head gasket or a cracked head with no milk oil, or oily coolant. The plastic fins bust off the water pumps on these things. they don't circulate and they overheat. Another pretty common issue with the engineering marvel that is the 4.0l sohc

 

[fritz24]

Does the overheating happen everytime you drive the car? You can test if you have a bad water pump when the car is idling, try to squeeze upper radiator hose,if it is hard and hot then your pump is good and fan clutch is bad. But if the hose feels like spongy and warm, it is the pump.

 

[axelofc69]

I had the system flushed. It was perfect for a couple of days. Then it started to do the overheating thing from cold. Id drive say to the store 5 min away. Fan would roar - temp would spike and go back down. Now its doing it every time I drive it. Of course goes away with speed. I topped up and it eventually purges fluid out of expansion tank.

yeah - when i replaced the water pump on my SAAB i got my own pump. mechanic said make sure i didnt get one with plastic impeller.

Being that the damn thermostat housing is plastic I would bet the impeller is too.

I will do the check on hose when I get home.

 

[axelofc69]

Does the overheating happen everytime you drive the car? You can test if you have a bad water pump when the car is idling, try to squeeze upper radiator hose,if it is hard and hot then your pump is good and fan clutch is bad. But if the hose feels like spongy and warm, it is the pump.

I guess a bad clutch would cause overheat and shoot coolant into expansion tank

 

[fritz24]

Yes. Main function of the fan is to cool down the radiator.

 

[axelofc69]

Yes. Main function of the fan is to cool down the radiator.

even though fan is kicking in and roaring when it gets hot? well I guess if its not working right at low speed could be issues

 

[axelofc69]

ok - topped up coolant. Started - when motor was cold the upper hose soft and spongy. Took for a ten minute drive. Clutch never kicked in and when I got back upper hose was firm.

 

[fritz24]

Your fan clutch didn't kicked in? Like driving it with AC off and you didn't hear the roar from the clutch? Your upper hose is firm so it just mean it is building pressure and water pump is fine and fan clutch can't keep up with engine demand especially when running with AC on.

 

[axelofc69]

Always have A/C on.
So - fan clutch may be toast? This is last draw then it goes in for trade !!!

 

[fritz24]

Yes.

 

[axelofc69]

UPDATE: Im wondering if it is the fan clutch. So I topped it up and checked the upper hose. It was firm of course. It has not done any overheating or fan roaring since. Its been hto (SF Bay Area hot) 85-89 degrees. Its been on highway, in traffic, through drive through last few days and hasnt done it once? I was fiddling with electrical connector to fan clutch - so im wondering if it wasnt fully connected ?? Im going to watch next few days to see what it does.