2.3L ('83-'97) 94 running Hot

[eagle989898]

i have a 94 2.3 that seems to have a cooling problem i cant seem to figure out

i can drive to work in the mornings (about 15min) and the temperature gauge will read about normal but later in the day when hotter it will run much warmer way above normal but not quite overheating.
i can drive with the heat on and it run normal. but who wants to drive with the heat on in 95 degree weather. also having the ac on does effect the temperature but that to be expected. coolant doesn't seem to be leaking anywhere that i can see. so far i have

flushed the radiator
new radiator cap
new fan clutch
new thermostat
new water pump
new coolant temp sensor

i'm at a loss right now any help would be appreciated

 

[RonD]

Welcome to TRS

Temp gauge should show just below 1/2, after warm up, thats "normal"
Above 1/2 is OK when under a load, i.e. uphill, but 3/4 is overheating

Have you checked the engine after getting home, does it feel HOT?
Do you hear any bubbling after you shut off the engine?

 

[eagle989898]

Welcome to TRS

Temp gauge should show just below 1/2, after warm up, thats "normal"
Above 1/2 is OK when under a load, i.e. uphill, but 3/4 is overheating

Have you checked the engine after getting home, does it feel HOT?
Do you hear any bubbling after you shut off the engine?

the engine does feel hot after getting home checked the radiator hose with a temp clamp and is saying about 200 degrees on the upper radiator hose and about the same at temp sensor
i do hear bubbling after the engine is shut off but only sometimes.

 

[RonD]

I would change the sending unit for the gauge, also check the wire and gauge by grounding the wire

Drawing of the driver's side rear of the engine: https://repairguide.autozone.com/zn...6b43f/80/21/b7/e1//small/0996b43f8021b7e1.jpg

ECT(engine coolant temp) sender is the lower one, it has 1 wire, unplug the wire, use a jumper wire from a ground or battery negative, and connect it to that wire
Get in the cab and turn on the key, temp gauge should go up to HOT
If so wire and gauge are OK
Remove jumper

You will need to drain the coolant, or be real QUICK, lol, in swapping the senders
You want a temp SENDER.............NOT a sensor, they are way different

ECT sensor uses 5volts and is hooked to the computer

ECT sender uses 12volts and is hook to the gauge


Flushing radiator doesn't work very well, just FYI
Because it is running warmer when outside temp is warmer then I would guess radiator has clogged passages, and if running the heater(2nd radiator) helps lower temp then that would point to that as well

If you have a manual trans you can easily pull out the radiator to see how much it weighs, empty radiators are super light
And you can flip it to see if coolant flows out, if so it coolant that was stuck in blocked passages

If you have an automatic its harder because of the cooling lines, but probably should be done

 

[scotts90ranger]

If the radiator is original and the coolant hasn't been changed at normal intervals (I'm guilty on this, I only change the coolant when it has to be drained, and then only sometimes... I'm changing my habits) I would bet on the radiator, there aren't a whole lot of passages to get plugged...

I just bit the bullet on my F350 7.3L Diesel that was running hot towing, turns out the radiator was nearly plugged... it's sitting the the box from the replacement and I think it's still draining after a month...

If you have some patience testing a radiator is doable, first test is the temperature at the upper hose compared to the lower hose, you want about a 30 degree change between the two (upper will be hotter) or more if it's near thermostat temperature like you are seeing. If you have that then the radiator is likely working but maybe not enough. Next step is to make a grid (can be imaginary, but sometimes easier to mark with masking tape) across the radiator, 3x3 should be enough to get an idea and take an infrared temp gun and see the temperature in those 9 spots with the engine running. The temperature will likely be hotter by where the upper hose comes in but should have temperatures close to the upper hose temperature all across that side and decrease toward the lower hose side. If the fins in areas are close to outside temperature in more than one or two of those areas the radiator is plugged...

 

[eagle989898]

I would change the sending unit for the gauge, also check the wire and gauge by grounding the wire

Drawing of the driver's side rear of the engine: https://repairguide.autozone.com/zn...6b43f/80/21/b7/e1//small/0996b43f8021b7e1.jpg

ECT(engine coolant temp) sender is the lower one, it has 1 wire, unplug the wire, use a jumper wire from a ground or battery negative, and connect it to that wire
Get in the cab and turn on the key, temp gauge should go up to HOT
If so wire and gauge are OK
Remove jumper

You will need to drain the coolant, or be real QUICK, lol, in swapping the senders
You want a temp SENDER.............NOT a sensor, they are way different

ECT sensor uses 5volts and is hooked to the computer

ECT sender uses 12volts and is hook to the gauge


Flushing radiator doesn't work very well, just FYI
Because it is running warmer when outside temp is warmer then I would guess radiator has clogged passages, and if running the heater(2nd radiator) helps lower temp then that would point to that as well

If you have a manual trans you can easily pull out the radiator to see how much it weighs, empty radiators are super light
And you can flip it to see if coolant flows out, if so it coolant that was stuck in blocked passages

If you have an automatic its harder because of the cooling lines, but probably should be done

i have a new radiator coming Thursday.
today after i got home from work i went to check my fan and it spins more freely at operating temperature than it does when its cold. It also never seems to engage this shouldn't happen right?

 

[RonD]

Yes that shouldn't happen, so fan clutch may be bad

BUT.............fan clutch "locks" because of radiator heat, not engine heat, so as the center of the radiator heats up it heats up the spring on the front of the fan clutch which cause it to "lock" more and more the warmer it gets

So if radiator is clogged up in the center tubes........................well it just doesn't get hot there, so fan clutch doesn't get hot

Best to pull back shroud AFTER engine is warmed up, and then run your hand over the radiators fins, you will feel "cold spots" as you run your hand around

 

[tomw]

The fan should be doing nothing when driving at highway speeds. The fan clutch was developed to provide good airflow over the radiator when driving at slow speeds, yet not use a lot of energy driving a strong fan at highway speeds. The speed of travel is more than enough to keep a radiator within normal range when there are no problems.
Have you looked into the top of the radiator tank to inspect the ends of the tubes? If they are covered in 'bloom', you likely need a new radiator or the one you have needs to be cleaned or rodded out. I don't know if that is available anymore, so replacement is the likely solution.
tom