Not coming up to temp

[Nicacus]

Hello,
I just bought this explorer about a month ago, and I've been searching around hoping to find a solution to this problem I'm having with my 93 explorer sport 4WD. So far I haven't been able to fix it and now I'm stumped.

From searching around this seems to be a fairly common problem, but none of the fixes I have found have helped.

The engine never seems to come up to temperature, the gauge rarely (maybe once or twice since I've owned it) goes past the O in NORMAL
I've changed the thermostat, flushed the coolant, changed the temp sensor..
the only other thing I can think of is that maybe this has something to do with the radiator fan never shutting off. To test this I put a bag between the grill and radiator and grill to see if it would warm up. after doing this the needle went straight up how you would expect it to if it were working properly, and almost like clockwork went right back to the N.

I dont really think it's a sensor problem because the air coming out of the heater vents never really feels hot, only luke warm at best.
My biggest concern now is that the engine is running in open loop (I think that the right term) and therefor running extremely rich to compensate for the cold temperature. My last tank of fuel averaged 12.1 MPGs that seems pretty bad to me, even for an explorer, but then again these are all new to me.

This picture was taken after about 13 miles on the freeway

Any thoughts? Am I missing something stupid?
thanks in advance

 

[westfield]

Here's a highly unmechanical response for you...My 94 ex does exactly the same thing but the heater works real good - blowing out nice hot air..so i just figure it's the crappy guage.

 

[NFP]

What temps are you living in? I know that my truck warmed up sitting at startup last month, but now that temps are getting below the 20, the truck takes much longer to warm up (so damn cold outside)

As for the fan being on (biggest culprit in my eyes), maybe you have a faulty fan switch or someone hot wired it in the past...

 

[nitro71]

The temp gauge does say you are in the Normal zone.. seems Normal. I don't know a lot about the heating system but that is where I'd start at. Since you replaced the thermostat it can't be operating in open loop. Even if it were I don't know if it would not heat up. I suspect it is something with the heating system. Whether it be the blending part or the heat transfer part or.. Good luck!

 

[dogfriend]

Dude, I owned a 89 Ranger (bought new) and it was like that for 120K miles until I sold it. :


You might want to add some gas soon though.

 

[corkey]

i would experiment with a piece of cardboard between the grill and the rad, just use enough to get the temp up so the heat feels good,
i actually made an aluminum piece to go over my grill for the days of the cold,

http://www.explorerforum.com/forums/showthread.php?t=231320&highlight=wind+stopper

 

[shaggymane]

personally, I don't see anything wrong with where you're gauge sits. Better there than on the high side. Which temp sensor did you replace? The two prong one that talks to the computer or the single prong for the gauge?
clutch fan - always on would be a problem. Some one here had a rather simple way of testing the clutch fan, can't remember who.

found it, by Mr Shorty: Definitely a possibility. Another possibility I would suggest checking is the fan clutch. Best test I've seen for a fan clutch came from a Mitchell manual: pull fan clutch, disengage thermostatic spring on the front and rotate 1/4 CCW, reinstall and test drive. If overheating problem is resolved, fan clutch is bad. If problem still exists, problem is likely elsewhere.

CAn you get your hands on one of these?http://search.harborfreight.com/cpisearch/web/search.do?keyword=infared+thermometer&Submit=Go

Gas mileage for a sport. there's no reason not to be in the high teens. I get 20+ on the hiway with a 5spd. yeah,

For good mpg I'd be looking at FPR make sure it's not running high. 35lbs is target. http://search.harborfreight.com/cpisearch/web/search.do?keyword=fuel+pressure+tester&Submit=Go

Check that MAF with a DVOM.

Breathability - a muffler something like this one http://shop.advanceautoparts.com/we...tId=-49826340&quantity=1&appId=&zipCode=66605

Check the blend door in the heater to make sure it's closing all the way. Disconnected from the control you ought to hear a thunk type sound when it goes to it's limits

 

[Tony H]

I went through the same thing when I bought mine. I too would have assumed the Middle of the guage would be where it should sit. nope. The "O" seems to be where it belongs.

 

[Skydiver]

Hello,

The Temp reading on your gauge is the normal average temp for the Ford Explorer. In addition, most of Fords SUVs and light trucks during those years operate near that temp reading. If everything is functioning properly, you'll never see the temp needle read on the "O" or above while driving fair weather days.

The best three things you can do now is check your Thermostatic Fan Clutch, cover about half of your Radiator with something and change your Heater Core.

shaggymane (above) mentions how to check the Fan Clutch operation. Also, your Haynes manual has a nice easy way to check for proper operation.
A quick easy check you can do is open your hood, start the engine after it is cold (cold start), jump around to the front and listen for the fan. For a few seconds up to, I think, a minute or so the fan will "roar". This is normal. After a few seconds up to a minute or so the "roar" should audibly decrease, it might even become inaudible over the engine noise. this too is normal. Now drive the Ex around till it reaches operating temp (blocking most of radiator surface but leaving its center open for airflow to the fan clutch helps). Get out and listen for the fan "roar" again. You should notice at least some increase again in the sound level. This will tell you that the fan is working or if its not but this doesn't really let you know if it is over cooling. This is my quick and lazy test. The Haynes manual test is pretty simple and more than thorough enough to show you if there is a problem, give it a look-see.

Cardboard against the leading edge of the radiator works great and can be removed quickly by hand if you ever have the need to regain more cooling temporarily and thrown in the back for later use. It's free, no tools are needed and it takes 20 seconds to put it in or pull it off in a pinch.

Your Heater Core most likely has at least some buildup in it and this will greatly reduce how well it heats your passenger compartment. At worst it will have enough buildup to restrict most hot coolant flow through itself. Even light buildup can act as a sort of insulator in the heater core's inside and easily reduce heat transfer.

A quick way to check for a heater core restriction is start your engine and feel both heater core hoses every minute or two as the engine begins to warm up. Both hoses should feel warmer to the touch each time and they both should feel equal in temp. One cool hose and one warm hose will indicate a restriction for certain.
Good coolant flow through the heater core will also help hold a more stable coolant temp during operation.

and this too ! vvv

You might want to add some gas soon though.

 

[Nicacus]

Thanks for all the ideas so far, I'll get back on and answer the questions, when I get home from work. Thanks again

 

[TooManyTrucks]

When you changed the thermostat was degree did you put in..I would suggest 195 degree. The lower temp thermostats (180 and 160) will never heat up our engines to operating temps.

 

[2000StreetRod]

ECT & Fuel Economy

When you changed the thermostat what degree did you put in..I would suggest 195 degree. The lower temp thermostats (180 and 160) will never heat up our engines to operating temps.

Good point! Also, the lower temperature thermostats reduce fuel economy because the PCM richens the mixture based on engine coolant temperature.

 

[malohnes]

I have had the same problem you have, however I am working on another issue. I strongly suggest you THOROUGHLY flush your rad and heater box as you most likely have a lot of loose floating buildup. I had scum coming out when I did it the first time and my temp gauge still hardly comes up to O and my heater is cool. I have to flush mine some more as I still have discolored clumps appear in the overflow can. Do a search...it is really easy to do, but a bit of work.

 

[Nicacus]

What temps are you living in? I know that my truck warmed up sitting at startup last month, but now that temps are getting below the 20, the truck takes much longer to warm up (so damn cold outside)

As for the fan being on (biggest culprit in my eyes), maybe you have a faulty fan switch or someone hot wired it in the past...

I live in Salt Lake City, on the way home from work today it was about 9* outside. I work about 16 miles away, never came up to temp, even with the radiator blocked off. I know for a fact the fan is staying on full blast as soon as the engine is on. is there a quick way to see if someone wired it to be that way?

Dude, I owned a 89 Ranger (bought new) and it was like that for 120K miles until I sold it. :


You might want to add some gas soon though.

The gas gauge is also dead, I'm guessing the fuel sender float is full of holes :

i would experiment with a piece of cardboard between the grill and the rad, just use enough to get the temp up so the heat feels good,
i actually made an aluminum piece to go over my grill for the days of the cold,

http://www.explorerforum.com/forums/showthread.php?t=231320&highlight=wind+stopper

I tried this last night, not to the extent you went though
I used a salt bag:

Beautiful I know

personally, I don't see anything wrong with where you're gauge sits. Better there than on the high side. Which temp sensor did you replace? The two prong one that talks to the computer or the single prong for the gauge?
clutch fan - always on would be a problem. Some one here had a rather simple way of testing the clutch fan, can't remember who.

found it, by Mr Shorty: Definitely a possibility. Another possibility I would suggest checking is the fan clutch. Best test I've seen for a fan clutch came from a Mitchell manual: pull fan clutch, disengage thermostatic spring on the front and rotate 1/4 CCW, reinstall and test drive. If overheating problem is resolved, fan clutch is bad. If problem still exists, problem is likely elsewhere.

CAn you get your hands on one of these?http://search.harborfreight.com/cpisearch/web/search.do?keyword=infared+thermometer&Submit=Go

Gas mileage for a sport. there's no reason not to be in the high teens. I get 20+ on the hiway with a 5spd. yeah,

For good mpg I'd be looking at FPR make sure it's not running high. 35lbs is target. http://search.harborfreight.com/cpisearch/web/search.do?keyword=fuel+pressure+tester&Submit=Go

Check that MAF with a DVOM.

Breathability - a muffler something like this one http://shop.advanceautoparts.com/we...tId=-49826340&quantity=1&appId=&zipCode=66605

Check the blend door in the heater to make sure it's closing all the way. Disconnected from the control you ought to hear a thunk type sound when it goes to it's limits

I replaced the temp sensor that's right under the throttle body, (two prong)

I'll have to see about getting one of those IR temp gauges, good idea.

It has a magnaflow muffler on it that exits directly after the muffler (no tail pipe, I know not so good, it's on the list of things to do)

I have a fuel pressure tester already, I'll hook that up on my next day off to see what's going on there.

I do hear the clunking sound when I move the blend control to one side or the other with a bit of force.

Hello,

The Temp reading on your gauge is the normal average temp for the Ford Explorer. In addition, most of Fords SUVs and light trucks during those years operate near that temp reading. If everything is functioning properly, you'll never see the temp needle read on the "O" or above while driving fair weather days.

A quick way to check for a heater core restriction is start your engine and feel both heater core hoses every minute or two as the engine begins to warm up. Both hoses should feel warmer to the touch each time and they both should feel equal in temp. One cool hose and one warm hose will indicate a restriction for certain.
Good coolant flow through the heater core will also help hold a more stable coolant temp during operation.

and this too ! vvv

That makes me feel somewhat better, the more I think about it, the more I think the heater core is clogged up. Before flushing the system I did notice the inlet pipe was extremely hot, whereas the outlet was hardly warm. Heater core will be the first thing I change

When you changed the thermostat was degree did you put in..I would suggest 195 degree. The lower temp thermostats (180 and 160) will never heat up our engines to operating temps.

I used a 195* from Napa

I have had the same problem you have, however I am working on another issue. I strongly suggest you THOROUGHLY flush your rad and heater box as you most likely have a lot of loose floating buildup. I had scum coming out when I did it the first time and my temp gauge still hardly comes up to O and my heater is cool. I have to flush mine some more as I still have discolored clumps appear in the overflow can. Do a search...it is really easy to do, but a bit of work.

I followed the super excellent awesome coolant flush thread when I did mine, and then some. hopefully the only thing that's clogged now is the heater core.

 

[Nicacus]

personally, I don't see anything wrong with where you're gauge sits. Better there than on the high side. Which temp sensor did you replace? The two prong one that talks to the computer or the single prong for the gauge?
clutch fan - always on would be a problem. Some one here had a rather simple way of testing the clutch fan, can't remember who.

found it, by Mr Shorty: Definitely a possibility. Another possibility I would suggest checking is the fan clutch. Best test I've seen for a fan clutch came from a Mitchell manual: pull fan clutch, disengage thermostatic spring on the front and rotate 1/4 CCW, reinstall and test drive. If overheating problem is resolved, fan clutch is bad. If problem still exists, problem is likely elsewhere.

CAn you get your hands on one of these?http://search.harborfreight.com/cpisearch/web/search.do?keyword=infared+thermometer&Submit=Go

Gas mileage for a sport. there's no reason not to be in the high teens. I get 20+ on the hiway with a 5spd. yeah,

For good mpg I'd be looking at FPR make sure it's not running high. 35lbs is target. http://search.harborfreight.com/cpisearch/web/search.do?keyword=fuel+pressure+tester&Submit=Go

Check that MAF with a DVOM.

Breathability - a muffler something like this one http://shop.advanceautoparts.com/we...tId=-49826340&quantity=1&appId=&zipCode=66605

Check the blend door in the heater to make sure it's closing all the way. Disconnected from the control you ought to hear a thunk type sound when it goes to it's limits

Forgot to mention this, the MAF is brand new the previous owner was a Ford mechanic, he changed it out along with the sparkplugs/wires and cylinder heads

 

[dogfriend]

Heater core will be the first thing I change
.

You are fortunate that you have a 1st Gen Explorer, the heater core is easy to change. The 2nd gen Explorers require that you remove the whole dashboard to get to it.

 

[Nicacus]

You are fortunate that you have a 1st Gen Explorer, the heater core is easy to change. The 2nd gen Explorers require that you remove the whole dashboard to get to it.

Good to hear, most of the other cars I've changed them on were built in the way that makes you think the heater core was hung on a wire, and then the rest of the car was put together around it.

 

[dogfriend]

My dad used to have a 68 Chevy Pickup, and you had to measure and drill a large hole in the firewall so you could take out one of the bolts holding the heater core in. :thumbdwn:

 

[shaggymane]

It has a magnaflow muffler on it that exits directly after the muffler (no tail pipe, I know not so good, it's on the list of things to do)

I ran a round for a year with a cherry bomb turbo dumping right after the muffler, just past the hanger, with a down angle piece at the end. No ill effect. Just bought the tailpipe section with resonator from advance auto 50.22$ Went on decently.

I have a fuel pressure tester already, I'll hook that up on my next day off to see what's going on there.

Believe the spec is 30 to 40lbs and there's a whole procedure for a complete test in the useful threads section. Mine was running 90lbs so no question about that. replace.

That makes me feel somewhat better, the more I think about it, the more I think the heater core is clogged up. Before flushing the system I did notice the inlet pipe was extremely hot, whereas the outlet was hardly warm. Heater core will be the first thing I change

I just assumed you flushed that too. A back flushing kit can be bought but I happened to have one of those old round brass things that goes on the end of a garden hose.(quick disconnect w/shutoff helps) Works great, fits right in the opening of the heater core.

Oh, you might find this a usefull tip if you haven't already thought of it. one heater hose goes over to the thermostat area. Take it off there. Take the other hose off at the heater core. then if you have another 3-4ft section of 5/8ths hose laying about connect it to the other pipe at the fire wall and direct the one that's gonna be used as an outlet over the fender and away.

Hope this helps.

 

[Nicacus]

I ran a round for a year with a cherry bomb turbo dumping right after the muffler, just past the hanger, with a down angle piece at the end. No ill effect. Just bought the tailpipe section with resonator from advance auto 50.22$ Went on decently.


Believe the spec is 30 to 40lbs and there's a whole procedure for a complete test in the useful threads section. Mine was running 90lbs so no question about that. replace.


I just assumed you flushed that too. A back flushing kit can be bought but I happened to have one of those old round brass things that goes on the end of a garden hose.(quick disconnect w/shutoff helps) Works great, fits right in the opening of the heater core.

Oh, you might find this a usefull tip if you haven't already thought of it. one heater hose goes over to the thermostat area. Take it off there. Take the other hose off at the heater core. then if you have another 3-4ft section of 5/8ths hose laying about connect it to the other pipe at the fire wall and direct the one that's gonna be used as an outlet over the fender and away.

Hope this helps.

I did use one of those prestone back flush kits when i did it, I'm guessing the heater core is still clogged up pretty good though.

I'll let you guys know what I find out.