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How To 180 Degree Thermostat (Write Up w/ Pics)

107K views 172 replies 54 participants last post by  Bubsue 
#1 · (Edited)
Parts you will need:
part #4128 (alternate part #15128) 180 degree thermostat from autozone $14.99
1 gallon of coolant coolant $10.99
=$25.98 plus tax.
I had a 20% percent discount and ended up spending $20.78 plus tax!
:smileup:

Depending on how many miles are on your truck, you may need to get a new gasket for the thermostat, the only problem is they do not sell just the gasket at any parts house i have check so u might have to buy the factory gasket and rob the gasket off of it. (part #41603 if you need it)

Comparison of the Old and New

Same Motorad as the Jet, Just Much Cheaper:


Tools you will need:
1 ratchet (i used a flexible)
1 6" wobble extension
13mm socket
Gloves if wanted



Procedure:
1. Let the engine be cool! Do NOT rush and burn yourself!
2. Loosen the clips that hold the upper radiator hose to the fan housing and loosely pry up, this will give you more room to work with once it's loose:


3.Locate the thermostat:

4. Remove the two 13mm bolts:

5. Move the upper radiator house to the side (keep clear of the belt and anything else as not to get coolant on it)

6. Pull out the old 203 degree Thermostat:

7. Remove the gasket off the old thermostat and place on the 180 degree thermostat:


Comparison of the Old And New Again:

8. Place new thermostat in housing, Note: it is a little tedious to get the gasket to completely go down but just go slow and work it around in small increments.

9. Place the 2 13mm bolts back in, fill up with coolant and your job is done.


Took me 15 min. to change out the thermostat and I didn't time it after that to warm it up and make sure everything was good. Very easy mod!

A big thanks to this mod goes to OLDHOTROD who provided the part numbers needed to do this write up!:smileup:

 
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#2 ·
Well done. The 180 stat is a nice little mod.
 
#4 ·
Nice work but why did you decide to do it? Years ago it was fairly common; some people changed them back and forth seasonally but I thought it was a bad idea now with computerized engine management.
 
#5 ·
Nice work but why did you decide to do it? Years ago it was fairly common; some people changed them back and forth seasonally but I thought it was a bad idea now with computerized engine management.
The reason it's problematic with electronic computer management is when the engine is warming up the computer senses the coolant temperature and adds fuel until it reaches operating temperature(sort of like a choke, except instead of limiting air, it adds fuel...same thing). Operating temperature is somewhere between 160-180 deg F for most vehicles. Running the 180 tstat USUALLY does not cause any issues. If you use one in very cold climates you'd probably be more prone to issues. And the issues would basically just be poorer mpg. It's a good mod, keeps the engine cooler (lasts longer and provides a small increase in power).
 
#7 ·
Everything he said, I live in Alabama and it does not get very cold. I have done a lot of research on this and couldn't stomach paying 60 for a thermostat so when I was given a part number I bit the bullet and did this write up while in the process.
 
#12 ·
so i was planing on doing this, but as stated in previous post, it said it could effect my mpg if i lived in a cold climate? I live in Montana and it is pretty cold here from Nov-Feb. anywhere from -20 to 40 during those months
 
#13 ·
It doesn't get Montana cold here but I have never had any ill effects from running the 180 stat in cold weather.
 
#15 ·
so i was planing on doing this, but as stated in previous post, it said it could effect my mpg if i lived in a cold climate? I live in Montana and it is pretty cold here from Nov-Feb. anywhere from -20 to 40 during those months
Most people don't experience issues. Only way to know is to try it and if your mpg decreases switch back to the stock tstat. Another option (sort of an in between) is to drill one or two 1/8" holes in the stock thermostat, to allow sort of a small leak through the thermostat, even when closed, and it will reduce the temp slightly. Also helps to prevent sticking tstat problems if they ever occur.
 
#16 ·
Most people don't experience issues. Only way to know is to try it and if your mpg decreases switch back to the stock tstat. Another option (sort of an in between) is to drill one or two 1/8" holes in the stock thermostat, to allow sort of a small leak through the thermostat, even when closed, and it will reduce the temp slightly. Also helps to prevent sticking tstat problems if they ever occur.
yeah i guess i can try it. It'll be hard to tell cuz the amount of time I let my truck warmup lol, thank god for heated seats.

Ill prolly be doing this mod some time this week. Is it a good idea to change out all the antifreeze at this point too?
 
#17 ·
If your antifreeze looks really nasty(clumpy/gritty) then it'd be wise to run a hose through it and flush it out. You can buy the prestone "T" piece that you clamp onto the heater hose line, then you hook a hose to it, and leave the bottom radiator hose disconnected and thermostat out, and run the engine and have the heater on, this will flush it out really well. If the coolant doesn't look bad just refill what was lost. I ALWAYS use the "mix with any color" stuff in any vehicle.
 
#20 ·
^ I didn't mean to scare people off. Many people in cold climates do this mod, successfully. People in canada do it succesfully. All I was getting at was if I do this in Orlando, FL, where it basically never gets below 30's, I definitely wouldn't have an issue. If you are in a cold climate, there's no guaranteeing, although you should be fine. Just have to monitor mpg and if you notice a decrease over several tanks, you would probably want to switch back to the stock tstat.
 
#21 ·
^couldn't agree more. I have only ran 1 tank though my truck so i cant comment on it yet. I will be going on a 5 hour trip and will be able to get some highway numbers as far as gas mileage goes next weekend
 
#25 ·
I havent adjusted my fan yet. Im not taking my mech. Fan off either. I dont think its nec. Unless it is removed, thats just my 2 cents though. Correct me if im wrong some1
If you installed a 180 tstat and are adjusting your efan settings to come on at a lower temp, it would be wise (not necessary) to remove the mechanical fan. You'd probably pick up some mpg without the mechanical fan. If you then experience issues with running hot (which you shouldn't ) then you could put it back on.
 
#27 ·
yeah it's not necessary. In stock form the electric fan only is used with the AC compressor on, or when the engine is starting to overheat (222 deg F is when it kicks on). This is as far as I know anyway...I swear I've heard my fan on around like 206 deg with AC off, but I don't know what my trans temp was.....I'm wondering if it also kicks on at a certain trans temp...
 
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