1993 Overheating when stopped

[TallestDutchman]

My 1993 Ford Explorer XLT gets hot when idling. Hot enough that the AC stops. The temp gauge doesn't peg out, but goes up to 3/4 maybe. Once I start moving the temp drops back down and the AC starts up again. No issues at all moving at 75mph on the interstate, just at red lights or sitting in a parking lot. I could be wrong, but that seems to be an airflow issue.

I have replaced the radiator, engine cooling fan clutch, and the thermostat. The new engine cooling fan is spinning and appears to be working properly.

Any ideas on how to correct this issue?

Edit - I did the water pump too. The coolant looks good, and the radiator and condenser look reasonably clean still. This has been an issue with the vehicle since I've owned it, it's not something that just started.

 

[92exp4x4]

Possibly replace the coolant temp sensor. It might be giving you incorrect values. Also, have you measured the actual temp of the rad and thermostat housing with a thermometer? There were also different fans. I think a 10 blade and 11 blade. Depending on options. What temp thermostat did you use? I only use motorcraft thermostats in these too. The aftermarket ones just seem to be inaccurate.

 

[94Eddie]

Typically, overheating when idling is indicative of lack of air flow through the radiator when the vehicle is stopped or moving slowly. This points to a partially clogged radiator or a bad clutch on fan assembly. The radiator could look fine from the outside and even looking down into the cap. Some, or all, of the tubes could still be clogged. The clutch fan should be noticeably harder to turn when the engine is hot and shut off versus when it is cold. I am assuming it has a clutch on the fan. I can't remember from when I owned my last 1st gen.

 

[92exp4x4]

Also I forgot to ask, do you have the two row radiator? And is the fan shroud installed? That can make a huge difference.

 

[nameiztaken]

replacing my standard duty (manual trans) fan clutch with severe duty (auto trans) fixed this for me. AC cools better than ever

 

[~X~]

This is the best price I have found on the severe duty fan clutch. I'm pretty sure 2nd gen fan with more blades will fit but I haven't tried it. Good luck.

https://www.oreillyauto.com/detail/c/murray-temperature-control/cooling---heating/cooling-fan-clutch/eaffd2dd4db4/murray-temperature-control-thermal-fan-clutch/odn0/2794/v/a/5256/automotive-suv-1994-ford-explorer

 

[1sicbronconut]

Un-bolt the radiator and take a look between it and the condensor, it could very well be backed full of stuff, are you running a fan shroud??

 

[TallestDutchman]

Possibly replace the coolant temp sensor. It might be giving you incorrect values. Also, have you measured the actual temp of the rad and thermostat housing with a thermometer? There were also different fans. I think a 10 blade and 11 blade. Depending on options. What temp thermostat did you use? I only use motorcraft thermostats in these too. The aftermarket ones just seem to be inaccurate.

Replaced with a new motorcraft brand. Forgot about that in the original post. Good idea though.
I have not taken an actual temp reading.
This fan has 9 blades.

Typically, overheating when idling is indicative of lack of air flow through the radiator when the vehicle is stopped or moving slowly. This points to a partially clogged radiator or a bad clutch on fan assembly. The radiator could look fine from the outside and even looking down into the cap. Some, or all, of the tubes could still be clogged. The clutch fan should be noticeably harder to turn when the engine is hot and shut off versus when it is cold. I am assuming it has a clutch on the fan. I can't remember from when I owned my last 1st gen.

I'll check it when it's warm. I paid to have the radiator installed, and may be making a bad assumption they did a proper flush at that time...

Also I forgot to ask, do you have the two row radiator? And is the fan shroud installed? That can make a huge difference.

It looks like a single row to me. Aluminum. There is a shroud.
I've never had to know anything about radiators, and didn't specify anything when I had it replaced.

Un-bolt the radiator and take a look between it and the condensor, it could very well be backed full of stuff, are you running a fan shroud??

It looked good behind the condenser. There is a fan shroud.



Thanks for the links to the fan clutches, I'll take a look to see if one will fit.

 

[92exp4x4]

Replaced with a new motorcraft brand. Forgot about that in the original post. Good idea though.
I have not taken an actual temp reading.
This fan has 9 blades.


I'll check it when it's warm. I paid to have the radiator installed, and may be making a bad assumption they did a proper flush at that time...



It looks like a single row to me. Aluminum. There is a shroud.
I've never had to know anything about radiators, and didn't specify anything when I had it replaced.



It looked good behind the condenser. There is a fan shroud.



Thanks for the links to the fan clutches, I'll take a look to see if one will fit.

View attachment 340876

In your pic I can tell you have a two row. It's basically the thick heavy duty radiator. The single row is half as thick.

 

[TallestDutchman]

In your pic I can tell you have a two row. It's basically the thick heavy duty radiator. The single row is half as thick.

This is valuable information, thank you. I was working from my phone yesterday and couldn't find much on how to tell the difference.

replacing my standard duty (manual trans) fan clutch with severe duty (auto trans) fixed this for me. AC cools better than ever

This is the best price I have found on the severe duty fan clutch. I'm pretty sure 2nd gen fan with more blades will fit but I haven't tried it. Good luck.

https://www.oreillyauto.com/detail/c/murray-temperature-control/cooling---heating/cooling-fan-clutch/eaffd2dd4db4/murray-temperature-control-thermal-fan-clutch/odn0/2794/v/a/5256/automotive-suv-1994-ford-explorer

The orielly website says this will fit my '93 XLT. I think that's the next step.

Does adding an extra fan blade make a difference? The current one has 9, Murray sells one with 10.

https://www.oreillyauto.com/detail/c/murray-temperature-control/cooling---heating/cooling-fan-blade/3a02d8828f66/murray-temperature-control-metal-plastic-fan-blade/vtc0/fa70332/v/a/5255/automotive-suv-1993-ford-explorer?q=cooling+fan+blade&pos=0

I will do a flush myself as well.
I haven't checked the clutch yet as per 94Eddie's reply, but think the whole thing is getting replaced anyway with the "severe duty" Murray linked in the post.


Thank you everyone.

 

[TallestDutchman]

I detected no noticeable difference spinning the fan blade when the motor is hot vs cold. I stopped and picked up the new Murray clutch and fan on the way home. I'll update when I get those in.

 

[92exp4x4]

Yes, having the extra blade will move more air. I think Explorers with auto trans and Ranger trucks with trailer tow or heavy duty cooling had the 10 blade fan. For some reason I remember seeing an 11 blade at some point. The explorer was basically a heavily optioned ranger, so most of the standard features on the ex were options on the ranger. Many components fit both vehicles and base parts will cross between the two models. Cheaper aftermarket parts suppliers will generalize their parts fitment for a given part even if it's not correct for the system it's installed within.

An example is that a 1991 2.3L ranger w/o AC and manual trans might have had the single row radiator and a 9 blade fan from the factory because that's all it needed. Those same parts will bolt into an explorer, but not be capable of keeping the bigger engine cool. And believe it or not, having the different options, probably saved Ford considerable money in material cost or all the parts would have been the same to begin with. The 4.0 and AC was standard in the ex, so it needed a higher capacity cooling system by default.

 

[TallestDutchman]

The new fan clutch and fan appears to have solved this issue. The fan is noticeably louder as well, I can hear it moving air.
Thanks for all the responses. Since it already had a new fan clutch in it, I don't know if I ever would have replaced it with the better Murray clutch.