Engine Overheating?

[DylanAB]

I have a 2006 Limited Explorer that has been in the family since new. Has been well maintained and taken care of. All of a sudden now though, it has been doing something strange with the temperature gauge. After about driving for about an hour or so or on a hotter day, the fan in front of the radiator will kick on and the temp gauge starts to rise. However, when I turn off the A/C, the fan turns back off and the gauge goes back to normal and stays there for the rest of the drive or until I turn the A/C back on. I have never had any issues with the cooling system on this vehicle or the A/C and this is a new issue to me. I am really trying to make this vehicle last as long as I possibly can. So any advice on this issue and how to also make this vehicle outlive me would be greatly appreciated.

 

[Fix4Dirt]

I have a 2006 Limited Explorer that has been in the family since new. Has been well maintained and taken care of. All of a sudden now though, it has been doing something strange with the temperature gauge. After about driving for about an hour or so or on a hotter day, the fan in front of the radiator will kick on and the temp gauge starts to rise. However, when I turn off the A/C, the fan turns back off and the gauge goes back to normal and stays there for the rest of the drive or until I turn the A/C back on. I have never had any issues with the cooling system on this vehicle or the A/C and this is a new issue to me. I am really trying to make this vehicle last as long as I possibly can. So any advice on this issue and how to also make this vehicle outlive me would be greatly appreciated.

v6 or v8

 

[DylanAB]

v6 or v8

It is the V8, mileage is 154,x... There are no leaks from anywhere in the engine.

 

[Fix4Dirt]

It is the V8, mileage is 154,x... There are no leaks from anywhere in the engine.

the AC will increase temps since it increases, load but it shouldnt overheat under normal circumstances.

so then i wonder:
1. a cooling system restriction/ineffectiveness
2. ECT but seems ok since the fan kicks in

how old is the coolant? any service done to that system?

 

[Turdle]

Does the temp gauge go outside normal range?

Fans should kick on with ac. Normal.

 

[D Hook]

Ever had the water pump replaced? My '06 has 172k on the original pump and had to get it replaced due to a leak from the seal.

Yours might be getting weak, still enough to cool under regular conditions (no AC) but not enough with a load on it.

 

[94Eddie]

I would check for a low coolant level first. If it is low then start checking for leaks. What seems to have happened is the cooling efficiency of the system is compromised and this is typically a result of a bad clutch fan, a partially clogged radiator or a water pump going bad. I have checked for bad water pumps and clogged radiators by removing the radiator cap when the engine is cold. Then letting the engine warm up to operating temperature and seeing if the coolant is flowing good when the engine is revved up a little. The radiator can be checked for hot spots with a laser thermometer but it might be difficult to get a reading without getting a hand chopped off by the fan since the AC condenser is mounted in front of the radiator. If the fan is going bad then you will notice overheating is worse under low speed driving than at highway speeds. At highway speeds the fan isn't needed much since air flow through the radiator is high just from the speed of the vehicle.

 

[07EddyB]

These Explorers are really good at eating radiators - if yours has never been replaced then I guarantee that's your problem. That's assuming you haven't checked your antifreeze level which you didn't mention so...
When the radiator starts leaking it usually does it in a way that no water ever hits the ground. I pools up in the lower support and blows back on the engine when the fan is running so you won't notice it unless you keep and eye on the remote reservoir and the radiator level.
If you do indeed have a full radiator then I would look at the thermostat also - they don't always stick closed or open. Sometimes it's in between.

 

[Bazz270]

the AC will increase temps since it increases, load but it shouldnt overheat under normal circumstances.

so then i wonder:
1. a cooling system restriction/ineffectiveness
2. ECT but seems ok since the fan kicks in

how old is the coolant? any service done to that system?

​

Well maintained ( i mean when the coolant leaks are the only problem) Gen4 triton wont overheat even with 1/2 coolant leaked out.

If no leaks detected (pressure check only,visual check wont work here because of the coolant possibly evaporated )radiator should be checked for exhaust evidence.

Look at the most problematic areas like an Y-fitting and radiator plastics parts,rear and front heater components.white evaporated coolant dust will be an evidence of the leak.

Check the radiator cap for bad seal and spring and check the thermostat as well (same symptoms)replace if bad.
Fan clutch and fan harness should be checked as well.Good condition cooling fan will produce extra loud high air flow ( i mean very loud ) at high engine temps.

Good luck

 

[Fix4Dirt]

Well maintained ( i mean when the coolant leaks are the only problem) Gen4 triton wont overheat even with 1/2 coolant leaked out.

If no leaks detected (pressure check only,visual check wont work here because of the coolant possibly evaporated )radiator should be checked for exhaust evidence.

Look at the most problematic areas like an Y-fitting and radiator plastics parts,rear and front heater components.white evaporated coolant dust will be an evidence of the leak.

Check the radiator cap for bad seal and spring and check the thermostat as well (same symptoms)replace if bad.
Fan clutch and fan harness should be checked as well.Good condition cooling fan will produce extra loud high air flow ( i mean very loud ) at high engine temps.

Good luck

oh ok! yeah i own a 2g so anything i say i this section is general usually.

 

[DylanAB]

the AC will increase temps since it increases, load but it shouldnt overheat under normal circumstances.

so then i wonder:
1. a cooling system restriction/ineffectiveness
2. ECT but seems ok since the fan kicks in

how old is the coolant? any service done to that system?

The coolant is fairly new. I replaced the water pump and thermostat back in February.

 

[DylanAB]

I would check for a low coolant level first. If it is low then start checking for leaks. What seems to have happened is the cooling efficiency of the system is compromised and this is typically a result of a bad clutch fan, a partially clogged radiator or a water pump going bad. I have checked for bad water pumps and clogged radiators by removing the radiator cap when the engine is cold. Then letting the engine warm up to operating temperature and seeing if the coolant is flowing good when the engine is revved up a little. The radiator can be checked for hot spots with a laser thermometer but it might be difficult to get a reading without getting a hand chopped off by the fan since the AC condenser is mounted in front of the radiator. If the fan is going bad then you will notice overheating is worse under low speed driving than at highway speeds. At highway speeds the fan isn't needed much since air flow through the radiator is high just from the speed of the vehicle.

I'll have to try this later today. Almost everything in the engine is still original since we've had it and I just replaced the water pump a couple months ago after noticing it was leaking near the bottom of the seal.

 

[94Eddie]

I'll have to try this later today. Almost everything in the engine is still original since we've had it and I just replaced the water pump a couple months ago after noticing it was leaking near the bottom of the seal.

One thing many of us here have done is to replace the 20 psi radiator cap with a 16 psi part. IMO, the main reason we see so many radiator failures in 4th gen Explorers and Mountaineers is due to the high pressure level of the cooling system. This might be why the hairline cracks commonly form in the plastic areas of the radiators in these vehicles. No one I am aware of has seen any issues with running a 16 psi cap. I replaced my 20 psi cap with a 16 psi one in January and have seen zero deviation in the temperature reading. This includes running the AC at full capacity in 100 degree temperatures this summer. This might save you from a radiator replacement down the road from cracking.

 

[DylanAB]

One thing many of us here have done is to replace the 20 psi radiator cap with a 16 psi part. IMO, the main reason we see so many radiator failures in 4th gen Explorers and Mountaineers is due to the high pressure level of the cooling system. This might be why the hairline cracks commonly form in the plastic areas of the radiators in these vehicles. No one I am aware of has seen any issues with running a 16 psi cap. I replaced my 20 psi cap with a 16 psi one in January and have seen zero deviation in the temperature reading. This includes running the AC at full capacity in 100 degree temperatures this summer. This might save you from a radiator replacement down the road from cracking.

I would like to check that also, but I can not find that part anywhere.

 

[94Eddie]

I would like to check that also, but I can not find that part anywhere.

See the link below. It is a direct replacement for the stock radiator cap.

Amazon product ASIN B000C5HRYK

 

[DylanAB]

An yup date to the issue. Replaced the thermostat and ran fine for half a day. There is no restrictions in any of the hoses and the thermostat works as should. The engine is still overheating intermittently now and makes a loud sound like an airplane taking off at acceleration and coming off of the highway. I have done some more research into this issue and seen a lot of things that lead back to the fan clutch going bad. any thoughts are more than welcome.