LX Thermostat Changeout Video *

[PowerWagon896]

2 PART VIDEO LINKS FOLLOWS TEXT

If you are not comfortable with changing to a thermostat (tstat) that has a lower operating temperature range than OEM, read no further.

tstat change-out
Changing the tstat can have significant advantages and will eliminate power lose due to heat soak if combined with an effective fan mod. Fan mods such as the “25-cent fan mod” or Jim Turner’s “Got Fan Mod?” will work. Changing the LX tstat is sooooooo easy, but I think some of you would feel more comfortable if you had a pictorial demonstration of this low dollar high benefit “mod”. It is best to do it when the engine is cold.

It can be done with a warm (NOT HOT) engine as long as you can touch the tstat housing without discomfort. If the engine is warm, relieve the pressure on the cooling system by slowly loosening the filler cap. When ALL pressure has been released, re-tighten the cap before proceeding.











You will need:

• 13mm socket
• medium length extension
• ratchet
• medium sized flat blade screw driver
• 1 gallon zip-lock bag
• The appropriate thermostat

Here is a link to Meister's excellent post on alternative tstats
Alternate thermostats for the LX Hemis - Lx Forums | Dodge Charger Challenger Magnum | SRT8 | Chrysler 300 Forum






OK you have all the tools, here goes.

• First, open the hood. You will see the tstat housing to the right (car right, your left as you face the front of the car) and below the intake.
• DO NOT REMOVE THE FILLER CAP UNTIL YOU ARE DONE AND READY TO REPLACE FLUID!
• Open the zip-lock bag and place it under the tstat housing, it will lay there if you place it right. Slowly loosen the tstat housing bolts. When the coolant starts to seep out, grab the zip-lock and place it under the housing while jiggling the housing. You should be able to catch most of the coolant and avoid making a mess. Finish removing the housing and place the housing, still attached to the hose, aside.
• While holding the zip-lock bag under the now exposed tstat, pry out the tstat with the screw driver. Again try to catch the coolant that will leak out.
• If you have removed the filler cap, hurry up and replace it as you will now lose all of the coolant above the tstat opening!
• Remove the gasket from the OEM tstat.

Here is where it can get tricky! If you have the 160* Milodon tstat you can proceed as it is an exact fit to OEM. If you have one of several 170*-180* replacements you will have to try the fit and perhaps file or grind some off of the O.D. to fit.











OK so you now have the tstat "fit" that you need.

• Place the gasket onto the new tstat and gently press the tstat into the recess, do not force it. If necessary remove more material from the O.D. to achieve a slight interference fit. Make sure that the tstat is facing the correct way. (it should be marked) Also, if the new tstat has a jiggle pin/bleed hole, position it to the top.
• Replace the tstat housing
• NOW you can open the filler cap and replace the coolant you saved in the zip-lock bag.
• Replace the filler cap, start up the Hemi and check for leaks.

You're done, have a beer.

Without a "fan mod" the coolant temperatures will still approach 190*-200*. With the fan mod I was running 165* staging, 175* at the end of the run. This was with the 160* Milodon tstat. This tstat is just a bit low for everyday driving and CAN throw codes during cool weather.

My coolant temps were running about 190* average on the way home after removing the 25-cent fan mod and replacing the fan relays. The ambient temperatures were about 83* that day. The 160* tstat can be installed @ home and driven to and from the track. It would be best to use some type of fan mod on the way to the track, but wait until the coolant reaches 180*before engaging the fan mod to avoid CELs.

Click on links below for the videos

(PART 1)
(PART 2)

[fnkychkn]

great video but your BIG popeye arms blocked the view of the ziplock's position catching the coolant.

[Token]

Good job, nice vid. I especially like the excellent editing, when the front bolt dropped to below and then was magically installed on the back, ready for tightening. BTW..... I did the exact same thing

[PowerWagon896]

great video but your BIG popeye arms blocked the view of the ziplock's position catching the coolant.

I did the best I could positioning the tri-pod. I had it leaning against the front facia with an 8" concrete block under 1 leg.

[PowerWagon896]

Good job, nice vid. I especially like the excellent editing, when the front bolt dropped to below and then was magically installed on the back, ready for tightening. BTW..... I did the exact same thing

Shhhhhhhhhhhhhh.

[hemiwagn]

There should be a contest to decipher what your tatoo says. Also, I liked the cat meowing at about the 6:12 mark.

Seriously though, great write-up! Takes all the mystery out of doing this mod. Thanks for taking the time to make it easy for the rest of us.

[Meister]

Excellent instructional video , PowerWagon896. Thanks much for taking the time to put it together.

It clearly shows just how simple it is to change the tstat in an LX Hemi.

I've edited post #1 of the Alternate Thermostats thread to include a link to this superb video. As I stated in my update post:

"This is a "must see" for anyone before your next tstat swap, even if you've done it before.".

Mega kudos.

[Token]

Yup, really nice Powerwagon, such a simple 5 minute job a chimp could do it.

[PowerWagon896]

Yup, really nice Powerwagon, such a simple 5 minute job a chimp could do it.

EASY NOW!

[mikesmagrt]

Great Diy Post And Video !!

Thanks

[Ozzie]

Thanks for taking the time to put this together. You've made this task WAY less daunting for me to consider!

[Fondy]

hey great job on the video. i always wounderd how that was done and now i know.

thankyou

[wquiles]

Thanks so much for taking the time to make the video

Will

[Lost815]

Yup, really nice Powerwagon, such a simple 5 minute job a chimp could do it.

shoudn't be a caveman can do it.

[desmo_dude]

The local Autozones (called 3 of them) all said that their computers show the Prestone 170 Tstat (pn 983170) has been recalled. They are no longer available. Any idea why? I wonder if it has to do with the fail-open feature. Or maybe it's a regional thing (seeing how it would increase emissions).

On a side note, I'm still on the fence as to whether I want to do this mod, due to many warning of premature wear of the motor and eventual loss of compression at these cooler temps... maybe I missed it, but what sort of before/after mileage have LX'ers been reporting with the mod?