Where does your temp gauge set @ "NORMAL" With A/C on?
 

I've been pondering this question for some years, and never really asked.

I have a '92, F-150, I-6 300, with 114,000 miles....
Where does your temp Gauge needle run about in "NORMAL" while driving between 60 and 70 mph with A/C on and Ambient air temp around 80-95 F?

I have replaced water pump, clutch fan, thermostat, rad. hoses, had A/C checked and charged. When I run the A/C either normal or recycled, I always watch the needle move into the "L" of NORMAL. I cannot remember what it used to run @ before I had numerous problems with the temp problem. But it all started about 3 years ago with the Fender mounted relay and has been borderline negotiable ever since. Also have checked Coolant mix and is at least 50/50 or 40/60 (coolant/water) mix, The only thing I can remember is that I after changing the water pump, I can remember the needle would go up and then down really fast, after the t-stat opened, and it was all cool then, but it never really does that anymore.

Another thing I remember is that after a cold winter morning, COLD! -25 below wiht wind chill, I said ok, cool, lets put a piece of cardbord in front of the rad, which I did and helpedout great, but one day after thing had warmed up and it was pushing 45-50 outside, I hard squalling form the fron with increased speed, 1st time and I nodded, 2nd time it did it later, I quickly turned off the truck, and inspected everything and just pulled the cardboard for safe measure and it never did it again.

I have also replaced everything with Ford parts, except the Fan clutch, which is Hayden, but I can also spin it freely, it does have a bit of friction behind it, but spins easier than I believe it should when hot, but I cannot tell if it's locking up when it reaches 170 F. It's a lot harder to spin when it's cold, which is normal. I have digital temp gauges also installed and when it's @ the "L" in NORMAL, it's about 225 F.

Any thoughts? Maybe I messed up the bearing in the water pump housing, but both the upper rad and lower rad are hot, with the upper being hotter, so I feel comfortable there since even when I change the coolant, I can see flow.

Thanks again for looking! Any thougths and ideas are welcome!

When I run the a/c in my '88 it seems like it gets up to the "M". That always catches my attention as she normally runs at or below the "N". I know my system is in perfect running condition so i just watch and keep on going.

Sounds to me as though you've done about all you can do. Are you using a 180 degree thermostat?

Tim

Did you flush out the engine and radiator when you put in the new pump and tstat?

Hey, thanks for the replies guys.

Yes, I did flush the system and have 2 twice since then. I know that there is an electrical problem sometime with the gauges sicne whenever I put the system under heavy electric load, the gauges actually go up, so I give myself some credit knowing that it isn't entirely pushing over the "L" in NORMAL. But I am wondering if it isn't maybe the aftermarket fan clutch and pondering on buying a new one, since I have heard that sometimes they really don't do as well as OEM. (On here, I have heard that). I have a new pump, 2-row rad, new hoses, new belt, I even installed 2 electric fans in front from a wrecked taurus. I checked the mix, 50/50, or leaner.

The t-stat is 192F, and that's from the factory, and had the shop check it as well. Only when I run the A/C does the system seem to completely go past the "M", and whenever I shut it back off, it dips back down to say under the "M".

I'm gonna have the parts have order me the ford fan, and go from there.

I wonder if changing the fan with spacing further out from mounting holes..well thats getting complicated..LOL

Well, if you guys have any other ideas, Id love to hear them.

Thanks again for the replies!

The t-stat should be fine, that's right where you want the motor to be so the computer entered closed-loop.

Are the efans and clutch fan fighting each other? The clutch driven fan or the efan (look for Skandocious' efan convert for info) should be more than enough on their own to cool that engine if they're properly shrouded. The fan shroud makes a huge difference, is yours on and intact?

The factory senders are...ehhhh...at best. I'd consider running an aftermarket temperature gauge at least temporarily so you can get the real numbers. There is a chance that your factory temp sensor is crap and you're not really "overheating" at all.

When you put your AC on, where's the heat load of the AC system going? Right in front of your radiator, so in effect that makes the radiator less efficent and makes it warmer than if you did not run the AC.

A lesson I just learned about today as a few of the company trucks are overheating just like yours. Had the same things flushed/replace too. Make sure your shouds are correctly in place and condenser of the AC is not plugged up with bugs and ect. A little than normal temp rise is OK with AC on, but should not overheat.

More replies, thanks again. I have tried with the just the Engine fan, and it is shrouded. Replaced it with a new one 2 years ago, that was torn up. I've also tried with the e-fans, but they only help when the engine @ idle in traffic, or hauling and towing at slow to idle speed. The condenser is clean as the rad is too. I keep them clean in the effect of trying to figure out the problem. Also there is a digital gauge for the water temp and when at 70 mph and A/C and ambient air temp, the elec. shows about 225-230 temp and the "L" on the OEM temp gauge.

if the weather holds out, I will look into other possible problems tomorrow.

Thanks again.

It appears to me that your radiator has marginal cooling capacity if it cant keep up with the extra cooling needed when the AC is on. Sometimes a flush just won't do it and a new radiator is your next step.

Mine operates at about between the N and the O on the normal range when fully warmed up regardless of outside temperature and if the AC is on. The only time it seems to ever go up is sitting in traffic when its 100 degrees outside. Even then it only goes up about 1-2 needle widths or to about the O.

i have a 90 with the straight 6 and here, in arizona with temps in the 100,s plus it will read mid point or a little lower when cruzing, when stopped at a light it miight go a little above mid.

I believe he said the radiator has already been replaced. Not to ask a stupid question, but I am assuming you changed the cap when you changed the radiator, right? I had an old Dakota that I chased a coolant problem around for weeks, swapped the rad cap, and problem solved. FWIW, my temp gauge creeps up to about 1/3 until the t-stat opens, then it drops to about 1/4, doesn't seem to matter whether it's hot or cold, empty or loaded, that's where it stays.:-blah

The Ford gauges are pretty unreliable. If you really want to know what your coolant temp is, install a real gauge. The Ford one is a guide at best.

I agree. I've changed out the gauges when I installed the cluster with tach on both my '95 and my '86 and both times the needle was on a different letter in "NORMAL"

Hello to everyone who viewed and/or replied. I have installed digital gauges and when I'm running 70 mph, w/AC on and ambient air temp about 85-90F, it resides in the "L". Digital gauge reading 225-235F.

I did notice one thing today as I pondered why the Parts house didn't get my Motocraft Fan clutch in today, that as I checked around the front housing of the spring, there is oil, gunky buildup around it and that around the bearing housing, nut, etc, there is some oily gunk around it. I do keep my rad and condenser clean, so after I rent the tool fo rthe fan clutch tomorrow, I'll have it off and can take a closer inspection.

Thanks for all the views and replies everyone! That question has bothered me for years! 8D

keeping one's cool
 

Have you considered that you may have the wrong water pump? Later models (those with the serpentine belt) use a reverse rotation pump. Consider also: Has a previous owner (or repair shop) put the wrong fan on your truck? I discovered that, on a 95 F150 I had bought, it had the older non-reverse rotation fan on it. While doing some other work on the truck several months ago, after parking it & leaving it idle in the drive that warm air was issuing forth from the grill: The fan was blowing forward! After changing the fan & clutch assembly the truck started cooling properly and the AC continued to cool even after coming to a stop while in traffic.

Also, when the radiator was replaced did it get the heavier two row type or the lighter single row?

dn.

On my 89 F250, the temp never goes past the N of normal, I know the engine is at normal operating temp too. I am about ready to replace ALL factory gauges with those from Harbor Freight, They are 2.25 Dia white with black lettering. For $20 each I may try them out(hope that they are better than factory in accuricy) I do have the vacuum gauge installed in my E350 bus and works good!

The HF store in my area has the vac, water temp, oil temp, volts, tach and boost gauges, you all may want to check them out. Also these are all electronic sending unit gauges too(execpt the vac and boost gauges)

225 to 235 is too hot and is verging on overheating. You definitely have a problem but since you've replaced everything in the cooling system I don't really know what the problem is. I was thinking the wrong waterpump as well.

When I switched over to the serp belt drive on my 84 F250 I6 300 I still used the v-pulley water pump, never had a problem. When I did replaced that water pump I got a newer year pump for that serp belt setup, I seen no change in the impeller design. The impellers where the stright fin kind which will work either direction(universal water pump?)

One way to check for water flow and is messy AND ABOVE ALL make sure the engine is cold!! Pull the tstat out and rehook up the hose, disconnect the upper radiator hose from radiator and move it so the out flowing water don't cause further problems, turn on a garden hose and keep the radiator full while starting and running the engine. A proper operating pump will move quite-a-bit of water from the upper hose! On a truck we did that test on, the water pump would empty the radiator/engine block in a few seconds!

If that shows good, the only thing I can think of is a plugged radiator core. Even flushing several times may not unplug badly plugged vanes.

WoW... that is a real headache.....
Mine runs on the R at the highest.... Last summer it started running hot W/ AC was in use... a clutch fan fixed the problem on mine....

The best thing I ever did was replace the radiator on mine.... I never had any heat inside the cab when it was real cold until I did that, changing the thermostat did nothing. That instantedly fixed a couple of problems on mine...
hope you find the problem on yours.....

I'm back again, with new updates!:

I did replace the fan clutch; New Motorcraft Fan clutch
I replaced the already 3 year-old belt tensioner!!! the housing was completely crack the width of the Alumnium cast body..WTF? 3 years-old!!

To Donnor: I did replace the lighter 1-row core with the heavier 2-row
(Haven't seen where there is much difference) Could that be what is causing the problem?!!

Before I put the new rad in, I did flush it. I have also flushed the entire cooling system, with the t-stat out.

I wonder if for some reason the "NEW" not reman water pump is somehow not doing what it is suppose too??

I remember when it would shoot to "O" then "R", then drop back down, it doesn't do that anymore. Also, someone asked if there was a new radiator cooling cap installed when I did everything, yes! Everything! New cap, t-stat, water pump, rad. I also had a problem with the rad cap, and it was on a GMC, 200$ and all it was 12$ cap!! Crazy..

Thank you everyone for tips, suggestions and feedback!! I think were are close to exhausting this Post, but every reply counts!!

Also, I forgot to ask...

what if I completely removed the t-stat, and closed it back up completely, then ran the truck on a day that was hot and the A/C, and see whether or not the pump wasn't working..

Maybe?

IDK?

More updates Everyone!

After some time, I finally decided on using my Craftmans multimeter,temperature display with thermocouple, to get a better idea and eliminate other possible problems.
Since I have setup my cooling system with the Prestone flush system, I decided I would disconnect the hose clamps on the hose that I believe goes directly from the water pump to the heater core, then makes the continous loop through the cooling system. After slipping in the thermocouple and reconnecting and making sure everything was tight and no leaks, I fired the 'ol girl up!

Today's Ambient Air Temp:78 @ 11:00 am

To my amazement, I watched it climb from 98, 115, 150, 170, 186, 190. At this time, I can still hold the upper radiator hose and it's 90 degrees.
while still holding the upper rad. hose, I watched the temp creep to *>192<*, and as it hit 193, I felt the hot coolant slowly start flowing. It hit 194, and then it started dropping! it stayed between 186-190 for 5-10 mins, with no A/C. After kicking in the A/C(NORM, NOT MAX((Recycled)), it went to 192-193 and stayed there. After easing it to 2000 RPM, it moved to 196, then dropped back down to 192. I finalled decided to hit 2500, and held it there for maybe 10 mins and it did get to 198-204, but never over!!! I let it back down gently, and it rested at about 750 RPM, and then the temp stayed around 198-206, but that is because the air it was getting while parked was 120, give or take 10 degrees, since there was no fresh, cooled air for it take say about maybe like 60/40, 70/30 (Engine heat/ambient air).

Anyone disagree with where the thermocouple was in the heater hose, let me know your thoughts. I will try the upper rad hose in a few days, and get another conclusion. I think my results were satisfying. I know now there is a definite electrical problem somewhere that'seading to high resistance, since my Temp gauge was @ *L* and my digital gauge was 224 F.

I know my volt gauge in the cluster makes wide swings whenever I turn on my eletric fans, headlights, A/C blower motor


Well, I hope everyone has Been enjoying the Weekend!
Any thougths or suggestions, I'd enjoy reading them!
again, thanks for everyone who replied on the topics and your experiences!8D

If possable try driving around with the thermocouple installed, Just reving the engine doesn't heat them up as much as driving down the road. More load, more heat out of engine. Also do you have a automatic or manual tranny. Sometimes a automatic tranny thats overheating will cause the engine temp to rise too via the tranny cooler in the radiator. I seen that many times when out 4x4ing, engines overheating due to the transmission torque converter getting too hot from slipping.

How's the aftermarket temp guage hooked up? You might have a bad engine to chassis(cab) ground. That would explain alot of the wierd readings you have.

Back Again! :)

I tried out what you suggested EddieC. I had the same temp with driving around, with and without A/C. I know there is a ground problem somewhere now, after all the crazy readings.

I'm just more relieved now that I took the extra step in locating my problems without tearing down the entire cooling system! :)

Also EddieC, it's a standard tranny. I want to Thank everyone again for replying with suggestions, experiences, and advice.

The Internet serves many purposes, I'm just glad this Forum is Up and Running 24/7-365 for help and advice.

:-jammin