Thermostat question on 2003 ford ranger
Thread Starter
|
Member
Joined: Jan 2018
Posts: 3
Likes: 0
From: MO
Thermostat question on 2003 ford ranger
I have a 2003 ford ranger 2.3 and to change the thermostat u have to buy a $140 housing is there any way to Jerry rig that and take out the housing I have in there and put a new thermostat on there or do I have to buy the whole thing ?
Welcome to the forum
You may have the last year of the electric thermostat, I thought 2002 was but..........if it has wires then you have an electric one.
You can get/use 2004 thermostat and housing, not electric, and much cheaper
But you need to leave the electric thermostat connected to its wiring, assuming you didn't get a code saying it was bad.
If you got a code about thermostat then check the fuse, if its OK then you will have to bite the bullet and replace it
If you don't have the code, you can just leave it plugged in and wire tie it out of the way.
The computer monitors if the electric thermostat is hooked up, if it isn't it sets a code and turns on the CEL(check engine light) not a big deal unless you have to pass inspections, but if there ever is a "real problem" you wouldn't know because CEL is already on all the time.
Ford couldn't get the correct thermostats made for the Rangers 2.3l Duratec engine, so they had to use the available heated/electric thermostats until non-electric could be designed and built.
so 2001-2003 2.3l had them, 2004 and up did not, it won't hurt anything to use the non-electric thermostats on the 2001-2003 models
You may have the last year of the electric thermostat, I thought 2002 was but..........if it has wires then you have an electric one.
You can get/use 2004 thermostat and housing, not electric, and much cheaper
But you need to leave the electric thermostat connected to its wiring, assuming you didn't get a code saying it was bad.
If you got a code about thermostat then check the fuse, if its OK then you will have to bite the bullet and replace it
If you don't have the code, you can just leave it plugged in and wire tie it out of the way.
The computer monitors if the electric thermostat is hooked up, if it isn't it sets a code and turns on the CEL(check engine light) not a big deal unless you have to pass inspections, but if there ever is a "real problem" you wouldn't know because CEL is already on all the time.
Ford couldn't get the correct thermostats made for the Rangers 2.3l Duratec engine, so they had to use the available heated/electric thermostats until non-electric could be designed and built.
so 2001-2003 2.3l had them, 2004 and up did not, it won't hurt anything to use the non-electric thermostats on the 2001-2003 models
Last edited by RonD; Jan 5, 2018 at 01:21 PM.
Thread Starter
|
Member
Joined: Jan 2018
Posts: 3
Likes: 0
From: MO
Welcome to the forum
You may have the last year of the electric thermostat, I thought 2002 was but..........if it has wires then you have an electric one.
You can get/use 2004 thermostat and housing, not electric, and much cheaper
But you need to leave the electric thermostat connected to its wiring, assuming you didn't get a code saying it was bad.
If you got a code about thermostat then check the fuse, if its OK then you will have to bite the bullet and replace it
If you don't have the code, you can just leave it plugged in and wire tie it out of the way.
The computer monitors if the electric thermostat is hooked up, if it isn't it sets a code and turns on the CEL(check engine light) not a big deal unless you have to pass inspections, but if there ever is a "real problem" you wouldn't know because CEL is already on all the time.
Ford couldn't get the correct thermostats made for the Rangers 2.3l Duratec engine, so they had to use the available heated/electric thermostats until non-electric could be designed and built.
so 2001-2003 2.3l had them, 2004 and up did not, it won't hurt anything to use the non-electric thermostats on the 2001-2003 models
You may have the last year of the electric thermostat, I thought 2002 was but..........if it has wires then you have an electric one.
You can get/use 2004 thermostat and housing, not electric, and much cheaper
But you need to leave the electric thermostat connected to its wiring, assuming you didn't get a code saying it was bad.
If you got a code about thermostat then check the fuse, if its OK then you will have to bite the bullet and replace it
If you don't have the code, you can just leave it plugged in and wire tie it out of the way.
The computer monitors if the electric thermostat is hooked up, if it isn't it sets a code and turns on the CEL(check engine light) not a big deal unless you have to pass inspections, but if there ever is a "real problem" you wouldn't know because CEL is already on all the time.
Ford couldn't get the correct thermostats made for the Rangers 2.3l Duratec engine, so they had to use the available heated/electric thermostats until non-electric could be designed and built.
so 2001-2003 2.3l had them, 2004 and up did not, it won't hurt anything to use the non-electric thermostats on the 2001-2003 models
So I just buy the 2004 housing and install it then wire tie the old on to something and leave the whole housing out just bye it’s self with the plug in attachted ? And is there any way to take my housing off and replace literally just the thermostat in there instead of the whole housing
Last edited by Jordanyoung; Jan 6, 2018 at 08:25 AM.
Can't say about the disassembly, never tried it
But you would have to buy the electric model to get the correct opening temp when heated, so.........might as well just put whole unit in
The 2004 models would open at a different temp, lower temp since they are not heated
Upper hose thermostats open at 195degF approx.
Lower hose thermostats, unheated, would be 175degF approx.
Reason being is that a rad provides 15-20degF cooling as hot coolant flows in from the top and down to the bottom.
When coolant in lower part of engine is at 175 degF thermostat opens and coolant starts to flow thru upper hose to rad
I should have asked why you are doing any thermostat work?
Under heating, too much flow?
Overheating, not enough flow?
But you would have to buy the electric model to get the correct opening temp when heated, so.........might as well just put whole unit in
The 2004 models would open at a different temp, lower temp since they are not heated
Upper hose thermostats open at 195degF approx.
Lower hose thermostats, unheated, would be 175degF approx.
Reason being is that a rad provides 15-20degF cooling as hot coolant flows in from the top and down to the bottom.
When coolant in lower part of engine is at 175 degF thermostat opens and coolant starts to flow thru upper hose to rad
I should have asked why you are doing any thermostat work?
Under heating, too much flow?
Overheating, not enough flow?
Thread Starter
|
Member
Joined: Jan 2018
Posts: 3
Likes: 0
From: MO
Can't say about the disassembly, never tried it
But you would have to buy the electric model to get the correct opening temp when heated, so.........might as well just put whole unit in
The 2004 models would open at a different temp, lower temp since they are not heated
Upper hose thermostats open at 195degF approx.
Lower hose thermostats, unheated, would be 175degF approx.
Reason being is that a rad provides 15-20degF cooling as hot coolant flows in from the top and down to the bottom.
When coolant in lower part of engine is at 175 degF thermostat opens and coolant starts to flow thru upper hose to rad
I should have asked why you are doing any thermostat work?
Under heating, too much flow?
Overheating, not enough flow?
But you would have to buy the electric model to get the correct opening temp when heated, so.........might as well just put whole unit in
The 2004 models would open at a different temp, lower temp since they are not heated
Upper hose thermostats open at 195degF approx.
Lower hose thermostats, unheated, would be 175degF approx.
Reason being is that a rad provides 15-20degF cooling as hot coolant flows in from the top and down to the bottom.
When coolant in lower part of engine is at 175 degF thermostat opens and coolant starts to flow thru upper hose to rad
I should have asked why you are doing any thermostat work?
Under heating, too much flow?
Overheating, not enough flow?
Ok long story but I’ll try to keep it short I had a coolant leak for a while it wasn’t much but enough where I had to fill IOC my coolant tank once a week or so and it was like that for a while then I took it to a shop and they replaced my coolant tank cuz it had a crack in the top of it then they pressurized the system and found out my water pump was leaking so then they changed that so now I have no leak but a day before I took it to the shop my guaze quit working completely and has came back on yet and before I took it in if I filled up the coolant tank I would get heat eventually and now since there is no leak I get heat just fine but the guy at the shop said it might be the temperature sending unit gone bad that’s y my gauge isn’t working so I bought one of those and I haven’t changed it yet I’m gunna try to do it tonight it’s pretty easy I just have to find the time but idk if it was my gauge being off for a week or so but I got a code last week for just one day on the way to work and then cleared it and it hasn’t come back since it was something about the thermostat but u want to try the sending unit bonfire I spend the money on the thermostat I asked the question just because if I have to change the thermostat I wanted to know lol sorry for not keeping it short and to clarify it’s my coolant reservoir that got changed and then the water pump and now no leak and heat but still no gauge which was fine for a long time when I had the initial leak but a day before it got fixed it’s been out
This thread has pictures, at the end, of ECT sensor location: https://www.ranger-forums.com/dohc-2...t-sensor-8063/
Hard to get to
The 2.3l Duratec engine(2001-2012 Rangers) was designed to mount sideways in a Cars engine bay, so mounted in a Ranger some of the parts are hard to get to
2.3l has two temp sensors
CHT(cylinder head temp) sensor
ECT(engine coolant temp) sensor
ECT sensor is used for the dash gauge but also reports temp to PCM(computer)
CHT sensor just goes to PCM
You can test any vehicles thermostat by feeling upper radiator hose
Thermostats purpose is to restrict flow thru the radiator until it is needed
Radiator is there to get rid of "extra heat"
Engine needs to run with coolant at about 190degF, gets best MPG at that temp
So thermostat shouldn't open until upper engine coolant is at 190degF.
Depending on outside temp, heating coolant to 190degF should take 5 to 8 minutes idling, faster if driving, but mixed bag there if outside temp is low, air flow cools engine pretty fast, lol.
So start cold engine and feel upper rad hose, at radiator end, should be cold of course
Wait a few minutes and feel it again, should still be cold, no flow thru radiator
If it is warming up with the engine then thermostat is open and should be closed.
You can also feel heater hoses they should be warming up with the engine
Thermostat that is stuck open will cause lower MPG, dirtier oil, cooler heater, and a temp gauge that doesn't get up past 1/4, it should get up close to 1/2 normally
Hard to get to
The 2.3l Duratec engine(2001-2012 Rangers) was designed to mount sideways in a Cars engine bay, so mounted in a Ranger some of the parts are hard to get to
2.3l has two temp sensors
CHT(cylinder head temp) sensor
ECT(engine coolant temp) sensor
ECT sensor is used for the dash gauge but also reports temp to PCM(computer)
CHT sensor just goes to PCM
You can test any vehicles thermostat by feeling upper radiator hose
Thermostats purpose is to restrict flow thru the radiator until it is needed
Radiator is there to get rid of "extra heat"
Engine needs to run with coolant at about 190degF, gets best MPG at that temp
So thermostat shouldn't open until upper engine coolant is at 190degF.
Depending on outside temp, heating coolant to 190degF should take 5 to 8 minutes idling, faster if driving, but mixed bag there if outside temp is low, air flow cools engine pretty fast, lol.
So start cold engine and feel upper rad hose, at radiator end, should be cold of course
Wait a few minutes and feel it again, should still be cold, no flow thru radiator
If it is warming up with the engine then thermostat is open and should be closed.
You can also feel heater hoses they should be warming up with the engine
Thermostat that is stuck open will cause lower MPG, dirtier oil, cooler heater, and a temp gauge that doesn't get up past 1/4, it should get up close to 1/2 normally
Thread
Thread Starter
Forum
Replies
Last Post
pubtime
DOHC - 2.3L Duratec / Mazda L Engines
13
Feb 23, 2026 01:34 PM
mitchellkend
General Ford Ranger Discussion
2
Nov 11, 2012 07:04 PM
bonez
General Ford Ranger Discussion
13
Apr 9, 2012 08:19 PM
zabeard
4.0L OHV & SOHC V6 Tech
19
Jun 29, 2007 04:47 PM
