4.0L Coolant Temp Spiking with A/C

[ARC95]

Hey everyone and thanks for having me,

Been browsing the forums and hoping someone could help me on this. Bought a 2010 4.0L explorer last month, and have recently been having problems with the temp gauge spiking on the higher side when driving, especially so when I have the A/C on. If I turn the A/C off, and turn heat on high it drops the temp down immediately to the center of the gauge. Bought a bluetooth OBD2 scanner that connects to my phone and saw temps as high as 230 F. Thought it could maybe be a stuck thermostat so I ordered a motorcraft one along with a simmonsautosportz aluminum housing, both of which I just replaced today. Went for a test drive around town and the same thing is still happening, driving with A/C on and after several minutes of driving my temp gauge starts to climb. We put in new coolant and made sure to have it run and fill it over the course of 20-30 minutes or so to make sure we didn't get any bubbles, before driving. What do you think it could be? Fan clutch, water pump, radiator cap? Any thoughts or experiences with the same problems would be appreciated! Another thing I will note is after the drive I looked under the front and did see some coolant dripping off the frame. I think it's from when we were filling as several times while filling we did overfill and spill some. After wiping it off and watching I didn't see any new coolant starting to pool on the underside.
Also engine has 99k on it.

 

[donalds]

Classic fan clutch
Imo

By the way 230 is bad you could kill your engine 100 different ways with temps like that

 

[ARC95]

Classic fan clutch
Imo

By the way 230 is bad you could kill your engine 100 different ways with temps like that

Fan clutch was next on the list, I'm not sure it ever truly got to that temp, it could have been an air bubble, it mostly stuck around 210 or so when driving and 230 was a short spike before we got temps down right away. Guess I'll try ordering a fan clutch

 

[donalds]

Fan clutch was next on the list, I'm not sure it ever truly got to that temp, it could have been an air bubble, it mostly stuck around 210 or so when driving and 230 was a short spike before we got temps down right away. Guess I'll try ordering a fan clutch

Order the heavy duty version

 

[ARC95]

Order the heavy duty version

Do you happen to know the model number of the Heavy Duty version or where I can get a good diagram breakdown? If so I'd appreciate it! Also once I can order and install I'll update the post on whether it solved my problem or not for everyone

 

[Lee's Automotive]

Order the heavy duty version

As donald said use the heavy duty version i have the hayden severe duty on my 99 explorer with the 4.0 SOHC and it runs around 195 200 max

 

[94Eddie]

I agree with Donalds in that the likely problem is the fan clutch. However, it could also be a clogged radiator or bad water pump. Does the temperture rise or fall to normal when driving at highway speeds? If it still overheats at highway speeds then it could be a clogged radiator or a bad water pump not not allowing enough coolant to circulate in sufficient volume.

 

[ARC95]

I agree with Donalds in that the likely problem is the fan clutch. However, it could also be a clogged radiator or bad water pump. Does the temperture rise or fall to normal when driving at highway speeds? If it still overheats at highway speeds then it could be a clogged radiator or a bad water pump not not allowing enough coolant to circulate in sufficient volume.

It mainly overheats when having the A/C ran. Temp spiked while driving both on the highway and in town going maybe 35 mph max. Same way to reduce temp was to turn off A/C, and we turned on heat for good measure to drop the temp

 

[94Eddie]

It mainly overheats when having the A/C ran. Temp spiked while driving both on the highway and in town going maybe 35 mph max. Same way to reduce temp was to turn off A/C, and we turned on heat for good measure to drop the temp

TBH, it sounds like it could be a bad water pump or most likely a clogged radiator. If it still overheats when going 55 mph, or more, then this would indicate the problem is not fan related. This is because at higher speeds enough air is forced through the condenser and radiator to cool the engine even though the fan isn't operating properly. Also, when running the AC the condenser puts a higher heat load on the radiator. It the radiator is clogged, then it can't handle the added heat it will see coming from the AC condenser. Also, you might want t check for debris in the AC condenser or radiator preventing proper air flow. A lot of times this debris can build up in the space between the condenser and radiator.

 

[ARC95]

TBH, it sounds like it could be a bad water pump or most likely a clogged radiator. If it still overheats when going 55 mph, or more, then this would indicate the problem is not fan related. This is because at higher speeds enough air is forced through the condenser and radiator to cool the engine even though the fan isn't operating properly.

That could also be it. What makes me think its a fan clutch is the ability for the engine to dump the heat by having the heat on, unless it's bypassing whatever is clogged in the radiator by going to the heater core instead? If the radiator was clogged I would assume overheating would still happen when running heat, albeit not as bad. When replacing the coolant, it did not blow heat until enough coolant was added to the system while burping everything. With A/C on, and driving on the highway it still has temp spikes, due to the extra strain of running the A/C I think. I also did a full drain and added new coolant when replacing the thermostat and housing. I didn't see anything in the coolant that would scream leak fix or anything. How can I check for a clogged radiator, or bad water pump if you don't mind me asking?

 

[donalds]

You should be able to turn your electric fan clutch on and off with forscan if you have it

 

[94Eddie]

That could also be it. What makes me think its a fan clutch is the ability for the engine to dump the heat by having the heat on, unless it's bypassing whatever is clogged in the radiator by going to the heater core instead? If the radiator was clogged I would assume overheating would still happen when running heat, albeit not as bad. When replacing the coolant, it did not blow heat until enough coolant was added to the system while burping everything. With A/C on, and driving on the highway it still has temp spikes, due to the extra strain of running the A/C I think. I also did a full drain and added new coolant when replacing the thermostat and housing. I didn't see anything in the coolant that would scream leak fix or anything. How can I check for a clogged radiator, or bad water pump if you don't mind me asking?

Using the inside heater to lower engine temperature is an age old trick to mitigate a fan, radiator or water pump problem. It doesn't point to a specific cause of the root problem. Since overheating occurs at highway speeds it points to a low flow problem in the cooling system and not a fan problem. The AC running means nothing in the analysis, IMO. It just adds more heat that the cooling system has to handle. Otherwise, it is independent of what is causing the root problem. The build up of scale in the radiator can restrict coolant flow and you won't see any sign of this in the coolant or other parts of the cooling system. Before throwing any more parts at the problem I recommend using a good engine flush that removes scale buildup and see if this helps. Drain and save your coolant and refill with water and add the flush. Then drain the cooling system and flush it with clean water and refill with your saved coolant and see if the problem is any better.

 

[donalds]

^^^^^ what he said

 

[ARC95]

Alright, I'll try to stop at the auto parts store tomorrow and get some radiator flushing fluid. Just watched a video on YT by ChrisFix for how to do it. He flushed twice with the cleaner, then used distilled water a few times to get it really clean. If I gotta clean it might as well do it well. I'll post how it ends up! Thank you all for your help so far

 

[94Eddie]

You're welcome. Most of us here love to help someone find a fix to a problem in an economical manner. The rest of the time we are just BS'ing with each other.

 

[D Hook]

I have a similar problem so I'll be watching this thread closely.
Good luck!

 

[ARC95]

Bit of an update, if anyone is interested. I went ahead and bought some rad flush and distilled water, about 10 gallons, along with new coolant. Was going to do the flush one day and saw a pretty consistent leak under the truck. Upon further inspection I saw a steady drip coming from what I now know is the water pump. Whether it's from the weep hole, or a failed seal I'm not sure, but after doing some digging it makes sense it would be a water pump problem. The area below it and is CAKED in black sludge, a combination of coolant and dirt I'm sure. So I'm going to be ordering a new water pump, and fan clutch and doing it myself along with some help from my dad. Of course, I'll also get a new belt while I'm in there. Wanted to see if anyone recommended changing anything else while I'm doing all this. I'll still do a flush, but after I have the new pump in, to make sure the radiator is all good. Fingers crossed I'll have no more problems after this!

 

[Lee's Automotive]

Bit of an update, if anyone is interested. I went ahead and bought some rad flush and distilled water, about 10 gallons, along with new coolant. Was going to do the flush one day and saw a pretty consistent leak under the truck. Upon further inspection I saw a steady drip coming from what I now know is the water pump. Whether it's from the weep hole, or a failed seal I'm not sure, but after doing some digging it makes sense it would be a water pump problem. The area below it and is CAKED in black sludge, a combination of coolant and dirt I'm sure. So I'm going to be ordering a new water pump, and fan clutch and doing it myself along with some help from my dad. Of course, I'll also get a new belt while I'm in there. Wanted to see if anyone recommended changing anything else while I'm doing all this. I'll still do a flush, but after I have the new pump in, to make sure the radiator is all good. Fingers crossed I'll have no more problems after this!

Get a motorcraft water pump and a hayden severe duty fan clutch

 

[ARC95]

Get a motorcraft water pump and a hayden severe duty fan clutch

If you don't mind me asking why a severe duty? Should I get a different fan blade then?

 

[Lee's Automotive]

If you don't mind me asking why a severe duty? Should I get a different fan blade then?

Check your fan blade for cracks if it has any cracks replace it asap also severe duty fan clutches in my experience are better than factory but i believe yours is all electric so your results may vary mines a 99