96 Ranger 2.3 - Engine running cold.

LandonRobinson · Jun 22, 2018

96 Ranger 2.3...

I just bought this truck a few weeks ago and one of the first things that I noticed was that the temp gauge was never making it into the middle of the normal zone, it climbs up out of being cold into the normal zone and then just sits right above the bottom mark, after maybe a long steep hill it will go up about an 1/8th of an inch.

If I put the climate controls on HEAT the cab does warm up and I can feel heat coming out of the vents but it seems like it should be hotter.

The upper radiator hose is really hot but still at the point where I can put my hand on it and not get burned, the truck also seems to be burning through more gasoline than it should be.

The radiator has a 16 pound radiator cap.

Today as soon as I got home I left the engine running and plugged my OBD-II scan tool into the truck and it says the engine temp is only at 188 degrees (F), while this is at the upper end of "cold-ish/warm" it seems like this is too low for normal operation and to get the engine computer to make the engine run as efficient as possible.

This is -probably- just a bad stuck open thermostat, but before I start tearing anything apart I was just wondering what temperature the engine should be at once it is fully warmed up?

RonD · Jun 22, 2018

Thermostat is working but may be the wrong one.
Should be a 195-198degF model.

But 188degF looks OK, thermostats start to open within 2deg +/- of rated temp, but are not FULLY open until coolant is 10-15degF above rated temp.

2.3l Lima engines don't generate alot of extra heat, people up north often cover radiator with cardboard in the winter months just to keep air flow thru engine bay down enough to get heater working

The temp SENDER should be on drivers side of engine toward the back, this means it will read a bit lower than actual temperature at the front upper hose.
Sender will have a single Red/white stripe wire connected, threads of sender are the ground

Heater..........after full warm up put Heat to HOT but fan on LOW
Open hood and feel the heater hoses at the fire wall
One will be slightly hotter, thats the IN hose
The other should be almost as hot if heater core has good flow

If it seems too cool, then turn fan to HIGH and test again, if it got alot cooler then core is plugged up.
MARK the IN and OUT hoses
Let engine cool off

You want to Back flush the heater core, maybe get a few more years out of it, maybe.
Remove heater hoses from firewall keep track of IN and OUT for flushing
You are going to put garden hose on the OUT connection to core, and flush it as well as possible.
THEN ........reverse the heater hoses on the firewall, so while driving it is also back flushing.
This reversing the hoses at the firewall should be done every time you change the coolant, on ANY vehicle, so every 2 years(green coolant) or 5 years(red coolant) depending the the coolant you use

adsm08 · Jun 22, 2018

This is a common issue with the 2.3L. As RonD said, they are cold blooded.

I am actually looking into making a 205* thermostat for the wife's Mustang so that she has heat in the winter. I also got a water neck from an OBD2 Ranger 2.3 that moves the computer's temp sensor out of the heater hose and into the water neck.

RonD · Jun 22, 2018

"They" do make 205degF or 208degF t-stats for the Lima engines, if memory serves, parts store may have to order it in

JJNOLA · Jul 12, 2018

adsm08 said:
This is a common issue with the 2.3L. As RonD said, they are cold blooded.

I am actually looking into making a 205* thermostat for the wife's Mustang so that she has heat in the winter. I also got a water neck from an OBD2 Ranger 2.3 that moves the computer's temp sensor out of the heater hose and into the water neck.

I just put that thermostat housing on my 94 too! Spiffy

Sent from my SM-G935P using Tapatalk

LandonRobinson · Sep 3, 2018

Well... I finally swapped out the thermostat with a brand new 195 degree one and plugged my scan tool in again to get the engine temp reading...

Just sitting at idle for 30 minutes it only made it up to about 172 degrees, but I revved the engine up to 3,000 rpms (where it spends most of its time) and within about 3 minutes it climbed all the way up to 197 degrees which is where the thermostat opened and the temp started coming back down.

After running for several minutes is finally settled on running between 192 and 195 degrees, the upper radiator hose is hot enough now that you cannot touch it without getting burned, so I'm considering that part of this as fixed.

But... I'm still having two other problems...

1. With the engine dead cold as soon as I start it the fan clutch activates the fan and it starts blowing cold air on the engine, as far as I am aware the clutch isn't supposed to activate until warm air starts blowing out of the radiator, its been a long time since I've had a vehicle with a fan clutch though...

So I'm assuming the fan clutch is bad and needs to be replaced am I correct with this?

2. The temp gauge on the dash is still sitting about 1/8" above the mark above the letter C at the bottom where it has been all along, so I have two questions for this...

- Where should it be normally sitting?

and

- What should the resistance be for the temp sensors on the engine?

cstarbard · Sep 3, 2018

I have a 96 2.3 as well. After a full coolant flush (done with prestone flush fluid and like 12 gallons of distilled water after that), my temp gauge never makes it past 1/8 up the gauge, but I do have great heat, it will drive you out of the cab. Even in cold weather.

I replaced the thermostat with a stock replacement while doing the flush, otherwise I just replaced the ect? which was on the thermostat housing tube. Merely because it got broken removing the thermostat housing tube. A while before that I replaced the blower motor resistor, which was toast, and the connector to it, which had welded itself to the resistor, that's all I have done to heating system besides flush coolant super thoroughly

My truck used to spark knock pretty bad before the coolant flush, and it read 1/4 up the temp gauge, if not a hair higher; it doesn't knock much if ever post coolant flush, and my coolant drains out looking like new, 1/8 up the gauge IMO is where a 96 2.3 probably should read at operating temp with the cooling system being well maintained and assuming the gauge reads right

How do you know the fan clutch is locking up? Listening to it? With engine off, how easy is the fan to turn? On mine it is very easy to turn with engine off. I'm under the impression that the fan clutch is designed to basically freewheel until its necessary for it to lockup but others would know better

Of course, once you're driving, the ram air effect (air flowing through your grille as you drive) does a lot more for you than a cooling fan, as I understand, but again others would know better.

I don't know anything compared to RonD and asdm08 so please take this with a grain of salt but I wonder if your heater core may be the issue? Clogged or something?

LandonRobinson · Sep 4, 2018

cstarbard said:
I have a 96 2.3 as well. After a full coolant flush (done with prestone flush fluid and like 12 gallons of distilled water after that), my temp gauge never makes it past 1/8 up the gauge, but I do have great heat, it will drive you out of the cab. Even in cold weather.

I replaced the thermostat with a stock replacement while doing the flush, otherwise I just replaced the ect? which was on the thermostat housing tube. Merely because it got broken removing the thermostat housing tube. A while before that I replaced the blower motor resistor, which was toast, and the connector to it, which had welded itself to the resistor, that's all I have done to heating system besides flush coolant super thoroughly

My truck used to spark knock pretty bad before the coolant flush, and it read 1/4 up the temp gauge, if not a hair higher; it doesn't knock much if ever post coolant flush, and my coolant drains out looking like new, 1/8 up the gauge IMO is where a 96 2.3 probably should read at operating temp with the cooling system being well maintained and assuming the gauge reads right

How do you know the fan clutch is locking up? Listening to it? With engine off, how easy is the fan to turn? On mine it is very easy to turn with engine off. I'm under the impression that the fan clutch is designed to basically freewheel until its necessary for it to lockup but others would know better

Of course, once you're driving, the ram air effect (air flowing through your grille as you drive) does a lot more for you than a cooling fan, as I understand, but again others would know better.

I don't know anything compared to RonD and asdm08 so please take this with a grain of salt but I wonder if your heater core may be the issue? Clogged or something?

Thanks for the reply.

Oh yeah with the extremely hot water that is coming out of the thermostat housing now keeping warm in the truck is going to be the least of my worries, well if 1/8" up is apparently the normal place for it than I'm just not going to worry about it anymore, my last car that I had for 7 years, and the car before it they both had the heat gauge needle right in the middle of the normal zone which is where all this confusion started from in the first place.

My main goal was to just get the engine up to the temperature that it should be so that I will stop getting crappy gas mileage, so mission accomplished in that regard.

That is my understanding of the fan clutch as well its just supposed to freewheel when things are cold and then lock when it gets hot and make the fan spin, so the answer to your question is that with the engine cold is it really easy to spin.

If I have time tomorrow morning I'll see what it does after I get to work which is a 25 mile drive which includes going up a steep pass through the mountains and then some moderate hills.

Even if the heater core was clogged 100% of the water would just go out the big hose to the top of the radiator and get cooled off anyway and I would get no heat in the cab at all...

But even before I replaced the thermostat I was getting heat in the cab that was warm enough to keep me warm on a 54 degree morning with nothing on but jeans and a T-shirt.

The previous owner took really good care of this truck, the antifreeze had no rust at all when I drained it, the brakes were brand new, and even the rear brake springs still had their paint colors on them, the tires were brand new, and the timing belt had been replaced 20k miles ago.

tomw · Sep 4, 2018

In most cases, a fan clutch will fail to move air. The fluid inside is metered by a spring-operated valve on the face of the clutch. As the spring gets hot, it rotates the valve stem and allows fluid flow.
You test them, such as it is, by trying to spin a cold fan. It should turn about 1/2 turn(ballpark... ) and come to a stop.
When cold, the fan will still turn, and pull air through the radiator. As the temperature goes up, on a good clutch, you should hear the fan 'flare up' as the clutch engages and REALLY starts to pull some air.
Most times they are worn out after a few years, and don't engage as well, nor pull as much air as desired for good A/C operation. It is a slow decrease in function, so it not noticed by most people.
Try spinning the fan when the engine is stopped and cold. If you can spin more than 1/2-3/4 of a turn, it's likely worn out.
tom

LandonRobinson · Sep 7, 2018

tomw said:
In most cases, a fan clutch will fail to move air. The fluid inside is metered by a spring-operated valve on the face of the clutch. As the spring gets hot, it rotates the valve stem and allows fluid flow.
You test them, such as it is, by trying to spin a cold fan. It should turn about 1/2 turn(ballpark... ) and come to a stop.
When cold, the fan will still turn, and pull air through the radiator. As the temperature goes up, on a good clutch, you should hear the fan 'flare up' as the clutch engages and REALLY starts to pull some air.
Most times they are worn out after a few years, and don't engage as well, nor pull as much air as desired for good A/C operation. It is a slow decrease in function, so it not noticed by most people.
Try spinning the fan when the engine is stopped and cold. If you can spin more than 1/2-3/4 of a turn, it's likely worn out.
tom

I finally tested it, it is easier to turn when it is cold than when it is hot and no it didn't spin very far, which is how I expected it to turn so I'm not going to worry about it anymore.

So please consider this issue *resolved*.

96 Ranger 2.3 - Engine running cold.

LandonRobinson

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