1997 explorer, overheating issues

[coll1ver]

Hi everyone. I have a 97 Explorer xlt, v6 4.0 ohv... The car overheats. New radiator, new fan clutch, new thermostat. I burped the air out of the car (I think). I can see the coolant flowing inside the radiator if i shine a flashlight in there. The car starts, heat is hot, warms up to operating temp and then temp gauge goes up to the point that Check Gauge light comes on for a few seconds, then comes down to normal. Does that pretty often during the ride. The thermostat is 198F. Would getting a thermostat rated for lower temp, such as 192 or 180 help?? I am running out of ideas of what else could be causing that. The head gasket seems to be ok. Please help anything would help and I would appreciate it!!! Thank you in advance!!!

 

[BTR]

Install a 180-degree thermostat.

 

[Turdle]

Water pump impeller could be slipping or corroded
. Check that lower radiator hose is not collapsing when hot engine is revved a bit

 

[Mbrooks420]

I’d do a dip style block test of the coolant, or hook up a pressure tester.

 

[1.8TTony]

Install a 180-degree thermostat.

Yes! Install 180° thermostat...........a 198° thermostat is WAY too high. I don't even know where a 198° thermostat would be used other than in certain race applications where higher engine temps are desired to momentarily create slightly higher power numbers.

From my experience, it is 100% possible that the metal fins on the water pump have eroded away resulting in poor coolant flow characteristics.

That being said:

Step 1: Install 180° thermostat and see what happens.

Step 2: Remove the water pump and inspect the fins on the back side of it. If the fins have eroded, replace the water pump.

Water pump removal is really simple. Just a small handful of tools are required to accomplish this task. If you've replaced the fan clutch recently, you can MOST certainly replace the water pump. Once the fan and shroud are out of the way, it's just a simple matter of disconnecting the coolant hoses and removing a bunch of 8mm bolts to get the pump off the motor.

If the pump looks good, and you've already replaced all the other parts you've mentioned, I'd (next) try some Prestone Heater Core/Radiator Flush.......the stuff is hreat for dissolving flaky, scale buildup.

 

[Fix4Dirt]

198 is definitely too high, 192 in this sohc. 180 is a bit low, imo. depends on your use. for application like towing etc then 180 is fine, but imo overall a 192 is good imo.

 

[coll1ver]

Thanks everybody!!! I'll try the steps all you guys have mentioned when i have some free time. I will let you guys know how it goes.

 

[Turdle]

Thanks everybody!!! I'll try the steps all you guys have mentioned when i have some free time. I will let you guys know how it goes.

If you haven't already done so, raise front of truck high. You want the radiator cap higher than heater core tubes in the firewall . Start engine let warm fully with HVAC turned to hot floor. Let cool completely , then , vehicle still raised, check radiator fluid at rad cap. Hopefully it's low due to air bubble lock. These are hard to burp

 

[coll1ver]

Hi folks, just wanted to give the heads up to the ones that are interested... Swapped out the thermostat to 180, jacked up the front and ran the car until it warmed up with heat blowing legs all the way up... The situation has gotten better, but it still goes up sometimes and comes back down quicker now... Did not have a chance to check the water pump because I do not have a garage and it has been snowing hard lately...Also while driving i've heard something similar to liquid going through pipes by the glove box... Thought coolant was going through the heater core. However I've ran the car while the front was jacked. So probably still got air in the system i guess? It did not burp a whole lot either.

 

[Josh P]

Easiest way to check the water pump is with an IR thermometer. Probe the upper and lower radiator hoses. There should be a spread of 18-20 degrees if your pump is working properly. Might be a good idea to get a 2nd temp gauge and compare the readings.

 

[1.8TTony]

How's the radiator cap? If it isn't sealing properly, you'll always get air sucked into the cooling system every time the engine cools off and the cooling system will never get pressure. If there's no pressure, the engine will overheat.

 

[1.8TTony]

Check out the YouTube video below........it shows the problem with a water pump. The vehicle is a Hyundai, but this same exact situation can happen with Ford Explorer water pumps. I've replaced hundreds of water pumps and it's NOT uncommon to find water pumps with impeller blades which have eroded away.

The main reason the impellers erode is due to electrolysis......... electrolysis is one result of using many different types of metals in an engine: Aluminum, brass, steel, cast iron, etc....

The impellers on these water pumps are made of tin. Tin is a really crappy metal. To prevent corrosion, I use H.O.A.T coolant in all my vehicles.

 

[Turdle]

Water sound through heater core means there is still some air in there.

Or, you are burning coolant.

 

[coll1ver]

Ok I will get a new radiator cap and see what it does... I have two old caps that most likely do not seal properly... If that does not work then hey I guess I'll have to buy a new water pump and give that a shot... Will have to find a garage space to do that in first because it is getting below 30 here already, not quite the sunshine I like to enjoy while working on my beast! Thanks everyone for you input I will let you guys know if the situation gets better. Otherwise I am looking forward to your suggestions! God bless!

 

[410Fortune]

thermostat only controls the minimum temperature
The computer needs to see 200 degree water temp to switch from closed loop to open loop
Factory thermostat for your truck is 195-198

Very common to get trapped air
One way to burp is to actually pour boiling water down upper radiator hose to backside of thermostat (Like from a coffee decanter)

It seems to me it is time for a waterpump replacement, they last 120-180K miles, past that you are asking for trouble
overheating this engine WILL result in head gasket failure and head cracks

 

[BobWiersema]

thermostat only controls the minimum temperature
The computer needs to see 200 degree water temp to switch from closed loop to open loop
Factory thermostat for your truck is 195-198

Very common to get trapped air
One way to burp is to actually pour boiling water down upper radiator hose to backside of thermostat (Like from a coffee decanter)

It seems to me it is time for a waterpump replacement, they last 120-180K miles, past that you are asking for trouble
overheating this engine WILL result in head gasket failure and head cracks

Not sure where you get the 195-198 but the engine came with a 180. I have the same engine in a 98. It's the second factory engine and they both came with 180° thermostats. The engine has never reached 200° even towing on a hot day with the a/c on. It runs between 175-185.

 

[DannyW]

Check that thermostat. Make sure the little hole is at the top - 12:00 position, or you will never get the air out.
-Dan

 

[Turdle]

Not sure where you get the 195-198 but the engine came with a 180. I have the same engine in a 98. It's the second factory engine and they both came with 180° thermostats. The engine has never reached 200° even towing on a hot day with the a/c on. It runs between 175-185.

195 is indeed factory temp on all explorers I am aware of. If you don't believe that 180 is an alternate temp thermostat, check rockauto. If you still doubt, call dealership for part.
Stock is 195 to 198. Coolant temps of 225 are completely normal.
P0217 code has never been seen on my mountaineer, while temp gauge was still in normal range, scangauge showing 226 coolant temp on i70 on way to Colorado on one occasion. Completed 1300 miles round trip without issue. Genuine Ford thermostat

 

[coll1ver]

Check that thermostat. Make sure the little hole is at the top - 12:00 position, or you will never get the air out.
-Dan

Yes I made sure the hole was on 12:00 position while installing a new thermostat.

 

[coll1ver]

thermostat only controls the minimum temperature
The computer needs to see 200 degree water temp to switch from closed loop to open loop
Factory thermostat for your truck is 195-198

Very common to get trapped air
One way to burp is to actually pour boiling water down upper radiator hose to backside of thermostat (Like from a coffee decanter)

It seems to me it is time for a waterpump replacement, they last 120-180K miles, past that you are asking for trouble
overheating this engine WILL result in head gasket failure and head cracks

Yes I have suspicions that my water pump is taking a crap on me..... The truck has 150k miles on it, and I believe the water pump has never been replaced. I mean the truck was heavily abused before I bought it seems like because all the parts were the original factory ones. So far I have replaced the shocks, the o2 sensors, spark plugs, wires, sway bar links, radiator, thermostat, fuel filter, and the oil filter. There still needs to be a lot of work done to it. Currently wanting to replace the valve gasket covers and ball joints. For some reason i have the urge to give the truck the love it deserves.