Overheating woes

[brdmh44]

Hi guy's, I am really baffled with my overheating issue and hope someone can give me some ideas here.

Anyways my problem started about three weeks ago when my temp gauge in the dash cluster started reading at around the A/L on the high side....along with that it was spewing coolant on shutdown. I proceded to pressure test the cooling system (which checked out ok) and then pressure tested my radiator cap - well the cap failed the test so I replaced it with an OEM 13 PSI cap.

For the next 2-3 days the truck remained "cool" but when the ambient temps shot back up, so did my trucks gauge

I have verified proper coolant levels, proper fan clutch operation, no restrictions in the radiator, I have blown out the radiator fins.

Just a few minutes on the way back to my house, the "temp light" below my wait to start light came on but I only had about 1 minute left in my commute so I drove it back and now it sits.

While all of this is occuring - I am not towing or hauling anything.

My other IDI trucks are not having any cooling issues in these temps so something goofy must be going on with this particular truck.

Any thoughts or suggestions would be appreciated.

PS - the truck is my '94 7.3 E4OD 2wd extended cab

 

[SparkandFire]

That "Temp" light should really be relabeled the "Armageddon" light because it clicks on right about 2 degrees before the core of your engine reaches nuclear thermal conditions...


I know my truck started acting very similar, then one day it reversed itself and starting running way too cool... I suspect the thermostat is becoming scrap metal.

Aside from that, how have you verified that the radiator is not plugged?

From my experience the fan clutch is mostly helpful during low speed or heavy pulling, on flat ground at highway speeds you should have enough airflow to keep the engine cool.

 

[brdmh44]

Yeah I had a funny feeling that when that light came on I needed to shut er down!

I know the radiator is clean solely due to the fact it was new when I installed the motor this past January.

It's usually reading in the middle of the gauge at highway speeds, but during the stop light grand prixs it loves to get hot.

I presume there is no way to verify thermostat operation without removing it? I suppose I can give that a shot and see what the heck happens.

This weekend I am going to install some aftermarket gauges (oil, trans, and water) ...I don't trust the stockers anymore.

When the engine temp light came on, my gauge was still reading on the hot side of "normal" so god only knows where it was even at

 

[SparkandFire]

Since the light comes off a different circuit than the gauge (it has it's own limit switch) it's a fairly good redundant indicator that something ain't right.

Really does sound like a thermostat. If everything else is in good shape, the thermostat is the next thing to check out. Just make sure you get either a Motorcraft or International thermostat... The stant ones are not correct for the IDI engine.

 

[OLDBULL8]

I presume there is no way to verify thermostat operation without removing it? I suppose I can give that a shot and see what the heck happens.

That's what I would suspect. Don't replace the t'stat with anything but a Ford or IH t'stat, others don't work right.

 

[brdmh44]

Thanks guy's, I really appreciate the quick responses!

I have a Ford dealer right around the corner,I will give them a shout and hope they have one!


Also, is it a 192 or a 195 that is correct as far as temps go?

And for the rest of you, where do you find your gauge normally reading at?

 

[icanfixall]

Ford or international only thermostat and they start to open at 192 degrees. Now a word about the cooling system senders and dash gauge. That "check engine dash lite comes on at 242 degrees and... It grounds out the dash gauge. So the gauge will travel way past the "L" in normal. To test this pull the wire to the large sender in the front port on the drivers side head. Ground it somehow and see the dash gauge pointer position. It will not matter where the pointer is when this grounding happens either. Sometimes these senders go bad causing all kinds of issues making you think your over heating. Now you may have a problem. That has not been ruled out just yet. Moving slowly in traffic and getting hotter than normal usualy means the fan clutch is gone bad. They don't last forever. If any wetness or dirt packed up around the spring or the shaft its gone bad and needs to be replaced. A mirroe is required to see the spring side. Did you use distilled water when you changed the radiator... If not the munerals may have dropped out and are plugging up the tubes. How many fins per in are on the new radiator compared to what you replaced. Were the tube counts the same... Just because you installed a new radiator does not mean you have a good cooling system. 16 fins per inch is the desired number of fins wanted. Around 54 tubes is a good number too. Usually a 4 row is the better radiators. A three row dimple core radiator is not what you want.

 

[brdmh44]

It was a Ford radiator new in the box - identical to the original one that was removed...

The thermostat did in fact come in today and I am currently in the process of changing it...

I will take note and verify that my sending units are not faulty as well.

Also, I noticed that my fan clutch is ALWAYS spinning...It never disengages. Is it possible for the air flowing throw the radiator to stall the fan? I don't suppose so, but I would appreciate on thoughts on that.

Thanks again everyone!

 

[pennsylvaniabo]

yeh my clutch fan goes 24/7 when the motor is running?

 

[SkipBurney]

I just finished putting my Chevrolet Silverado gasser back togther today, it was doing the exact same thing, I changed the thermostat and both upper and lower hoses while I was there with no luck. I disconnected the upper radiator hose and stuck a garden hose in the overflow tank and just let it sit and run, sat in the truck and spun it up to 2500 for about 15 minutes truck ran as cool as could be. I have always kept the antifreeze up to ***** but just on a whim I took the radiator to the shop to be checked and it was bout 75% plugged up. They pressure cleaned it out and flushed it for me for 45 bucks I put it back on burped the engine and it stays pegged on 190 all day long. My radiator looked fine as far as I could see but when I saw what came out I was surprised