Truck running cold....2.3L

[Nater]

When I bought the truck, the temp gauge never moved, or moved just the slightest bit (Never over the first mark on the cold side)
Ok, thought it might be a temp sensor problem, but before I went and spent money on a new sensor, I started to check some things. Radiator has been flushed along with the heater core. Now, I am basing my experience from my Mustang. The Mustangs upper radiator hose gets hot to the touch, and the truck gets luke warm/room temp. Never really thought about it till the weather started getting colder. Now that I am using the heater and the darn thing is blowing out room temp air, whereas the stang is blowing out melt your skin HOT air.....Leads me to believe that there is something up...Just cannot pin point it...Any ideas?
Things that I have done.....
Rad flush along with back flushing the heater core.
checked the thermostat using the boiling water method

 

[RangerFabWorks]

put a new 195 degree t-stat in it and call it a day. it might be stuck open. plus, its a 10 part. just cheap insurance and you could rule that out.

how does the truck run cold, whats the idle speed at? does it run rough? how bout when its "warmed up" then whats the idle speed at? and how does it run?

 

[Nater]

The T-stat opens and closes correctly. Checked this by using boiling water....
Truck runs great. No idea what it is idling at because I have no Tach. But if I had to guess, I would say anywhere between 800-900 rpms both cold and warm.

 

[dangerranger83]

When I had my 2.3 in my truck it never got warm enough to blow warm air. I fixed this problem by putting cardboard in front of the radiator. We do the same thing with my dads truck and it has a 2.8 liter.

 

[PFC Laird]

When I had my 2.3 in my truck it never got warm enough to blow warm air. I fixed this problem by putting cardboard in front of the radiator. We do the same thing with my dads truck and it has a 2.8 liter.

this worked well for mine also

 

[creepinjeepster]

From back flushing the core, you may now have a vapor lock that needs pushed out. Also would check and see if (when warmed up) any of your hoses are collapsing. 3rd thing to check would be your vent doors. Make sure they are moving all the way to the heat side and not leaving the cool side open. If this is happening, it will feel luke warm air because you're sucking in cold air from outside at the same time.

 

[Nater]

My dad used to do the cardboard trick too....Might try that....
How do I check the vents?

 

[modelageek]

This same thing happened to me in the truck I have. My engine would not warm up properly, I put a new t-stat in i got from napa. the problem was still there. I went and got a motorcraft f8cz-8575-aa t-stat and oring gasket ( I bet your truck calls for the same t-stat but i would check) I installed it correctly, there is a few stickys showing how to , some times you need to twist the t-stat in the housing. when i installed the new motorcraft I noticed that the old one from napa did not seat properly in the housing thus letting coolant pass by it. I also noticed that I had to make sure my coolant was completely full and i had to burp the air out of the system by squeezing the upper rad hose. if i did not do this the gauge would fluctuate when i revved the engine. I believe the sensor was not completely submerged in coolant and thus was getting a rush of coolant over it when i revved the engine. the truck has run fine and the heat works good, the temp on the gauge is normal. If your gauges are working properly and the truck is not warming up I would bet that the t-stat is your problem. ......please remember to post a conclusion once it is solved....

 

[modelageek]

Oh and I did the cardboard thing all last winter and it did help but my truck would take forever to warm up. I vowed to figure it out so this year i would have heat. I am know toasty warm...........

 

[modelageek]

IMHO. I woul use the Motorcraft recomended tstat. I think it is 190 or 192. The computer is programmed for the degree tstat. Also on my ebgine coolant is always reunning thru the heater core. The bypass is before the tstat
Just my opinion

 

[Sprag-O]

The 2.3's are prone to be fairly cold running engines. I had the same problem with mine when I got it back in '03, solution was to just put a piece of cardboard in the grille and run it. If I let it idle, it was a good 10-15 minutes before the T-stat wanted to open.

I then went and made it much worse by dropping in a 160F t-stat... but thats just me :-D

 

[scotts90ranger]

it's not just that, it's also that the temp gages read way wrong on 3/4 of them... my temp gage only goes up to the C mark, standing straight up is overheating area... I've learned to live with it after 9 years

 

[Nater]

I am off work on Friday, so I will take a look at it then and let you guys know....Had our first frost this morning. Gotta love scraping ice off the windows at 4 in the morning.....

 

[Larry02451]

I had the same problem. I replaced the heater core, heater hoses ( they had some gunk in the hoses and where they connected so I'm sure the heater core was partly stopped up) and the temp sending unit. Now my heater works real good. Also my temp gauge go up in the normal range a little bit.

 

[modelageek]

This issue was just solved on anther forum. If your upper rad is not getting hot. The tstat is either, stuck open, installed incorrectly or the wrong one. Install a new MOTORCRAFT TSTAT correctly. Get your upper rad hose so it gets hot. If still no heat we will go to the next step. You will never get good heat if your engine does not warm up properly. Oh and make sure you post a conclusion or we will come to your house and do very bad things to your truck. LOL