Hello everyone

The Aero fan clutch went bad and I replaced it for a "heavy duty" job and now it is run all the time.
I need to know if it is cause that the needle in the temp gauge not raise to the midle like previously
I replaced the sending unit and the ground works well.

Any idea on this will be useful for my.

Thanks in advance.

 

The fan running all the time should not cause over-cooling at the rad if the thermostat is functioning properly. If the thermostat is stuck open, though, it may over-cool. How recently has the cooling system been flushed & the thermostat replaced?

If your fan clutch had been malfunctioning fo a while, you may just be used to see it running hot. I have a 95 3.0L Aerostar. Under typical driving conditions, the temp gauge needle fluctuates around the "N" in NORMAL. On a hot summer day with a load, the temp gauge may hit the "R", but that's rare.

The other thing to keep in mind is that the fan really contributes to air flow through the rad at idle and stop'n'go traffic speeds. If you're moving at 30mph or more, the air forced through the grille is adequate to properly cool the rad.

I would be concerned about what effect the constantly running fan is having on your gas mileage. It takes energy to turn it and you pump that energy into the fuel tank on a regular basis. And of course any power used to turn the fan is power you're not getting at the rear wheels.

Cheers,
Eric

 

Thanks Eric for reply.

I flush the cooling system and replaced the thermostat two years ago.
May be the thermostat is stuck open.
How I know if it is open?

About the gas mileage, the cost has been increased too much.

 

its stuck open if both heater hoses stay cool, or just warm. they should get hot, or at least one of them. i replaced another thermastat this year. thats makes the third one in the van....rick

91 aerostar xl, ext
4.0 litre 193 thousand miles and going..............

 

Thanks buddies

Both heater hoses stay hot but the hoses in the rear heater core are cold even with the engine warm and the control **** in "vent" position.
I am going to replace fan clutch by the original one to see that it happens.
Any suggestion about heater Core on the to rear?. The vacuum lines are workin well and all connected.

Thanks in advance

 

Ok, I replaced fan clutch by original of factory this morning and engine is now quiet and the back wheels have more force when I accelerate, also does not exist a vibration that I feel in the floor and I am surprised by the low gas mileage. The needle of temp gauge raises until the "N" of NORMAL but it does not advance to the "R" like before. I am going to follow the recommendation of Eric and rick and I will change the thermostat and will flush the rad and hoses. Now my question is, How remove the thermostat? I wait for some instruction and its valuable aid like always.

 

I am having the same problem with a 95 3.0L 2WD. Just replaced the TStat, getting some heat, but the temp gauge barely sitting on the low side or the normal range line.

I was reading an earlier thread that says it was normal for the fan to run constantly, and the clutch was just varying the speed. Is this true?

I'll check the heater hose temps tonight when I get home to see if they are cool as well.

 

If you're going to flush the cooling system, I suggest you do that before you tackle the thermostat.

Follow the upper rad hose to the engine. The thermostat is located in the housing bolted to the intake manifold. Drain the coolant down to at least this level (drain valve on the rad or siphon it - preferably not by mouth). Disconnect the hose from the thermostat housing and then unbolt the housing, Be careful not to break the bolts. They can corrode into place & be extremely tight. A couple of sharp hits with a hammer may help free the bolts.

Once the housing is off, scrape the old gasket completely off both surfaces & try not to drop the scrapings into the engine.

Install the new thermostat with the spring end into the engine (guys! correct me if I'm mistaken - it's been a while!). Align the new gasket & bolt the housing back on. I would recommend putting some anti-seize on the bolt threads.

Refill the coolant - with these vans, you may have to keep topping it up for a few days if you get an air bubble trapped in the heater core. There are many threads here that discuss air bubbles in the heater core - do a search.

Good luck with your van.

Cheers,
Eric

 

Ok Eric, thanks a lot.
I'm going to do this tomorrow in the morning.
Ok Eric thank you very much.
Additionally I want to know how many liters of antifreeze/water (50/50) I must prepare for this 4.0 Lt. engine?
I will have to remove the two hoses (quick disconnection) that cross by opposite of the thermostat housing?

Thanks again.

 

Eric has it all laid out very well. I just want to add one thing. Heat up a pot of water and make sure the new thermostat opens up when it's supposed to. You don't want to put in a new thermostat and found out that it didn't work. It has happened to me before!!!!!!!!!!

Good luck

 

Thanks copper it is a very good idea.
I removed the thermostat and was surprised because she left in parts. Where they will be the other pieces of the thermostat? I do not know it.
Perhaps when I flush the system I find them.

 

I replaced my thermostat for a new one makes by Stant 192*(FOMOCO did not have one available)

I flush the sistem. I found an obstruction in the hose that comes from the water pump and leaves in form of "T". In this one section there was a composure that badly was done and had colapses the hose that takes water towards to rear heater Core, is why it did not work correctly. The parts of the thermostat that were lost never I found them. I suppose that they took off a year ago that I changed the water pump. Now temp gauge works correctly and the needle raises without problems until half of the NORMAL word ", when the temperature increases after 10 or 15 minutes the needle raises until the" M "and immediately it returns to the" R ". I believe that we fixed the problem of the temperature. Thanks to all you to help me greatly to solve it.

 

After all this work, I was making a reflection. All the problems that my system of cooling underwent were caused to place fan clutch of heavy duty in my system and not to follow the recommendation to change the thermostat once to the year. Now already I learned the lesson.

 

And thank God it's a cheap leasson too .