1997 4.0 t stat housing

[Bobby Simone]

I have started to get a leak from the housing and I have read that this is common due to lack of quality on a plastic part. I can't pay the cost of an Oem part but have heard there are fittment issues with aftermarket t stat housings. Anybody here know of a good aftermarket housing that will work. Thanks for your help.

 

[drdoom]

Dorman.

 

[XLTrunner]

Been there, done that...twice in the last 8 wks. Save yourself a lot of time and money and resist buying the Four Seasons & Dorman t-stats. Go with the Motorcraft conversion and be done with it.

I first installed a Four Seasons (which I believe is a Division of Dorman) and it lasted all of about 2 wks before it, too, started leaking. Unfortunately, this was before I had read all about the problems others had with these two brands. Replaced it with the upgrade Motorcraft housing and all is well after several wks and approx. 800 miles...even as the weather has gotten cold. So, pull up the Rockauto website and purchase these parts:

Pt.# RH144 - Lower T-Stat Housing @ $35.79
Pt.# RG614 - Lower T-Stat Housing Seal @ $3.46
Pt.# DY1269 - Sensor @ $21.79
Pt.# SW6146 - Sensor @ $21.79
Reuse existing Upper T-Stat Housing

You'll need the (2) metal clips that hold the sensors in place. Several sources for those:

Ford Pt.# W706800-5303
Dorman Pt.# 800-019
NAPA Pt.# NOE7305034

Don't forget to install a new thermostat o-ring...and may as well replace the thermostat at the same time. Oh...and, might consider replacing the short bypass hose that connects to the water pump while you're in there, too.

 

[swshawaii]

+1. Do not over tighten lower and upper bolts, spec is only 89 inch pounds. (7-8 ft/lbs.)

Yet to find a Dorman part with comparable build quality to OEM or that fits properly. JMO

4.0 SOHC plastic thermostat housing (Upgrade)
https://www.explorerforum.com/forums/showthread.php?t=239493

 

[Bobby Simone]

Been there, done that...twice in the last 8 wks. Save yourself a lot of time and money and resist buying the Four Seasons & Dorman t-stats. Go with the Motorcraft conversion and be done with it.

I first installed a Four Seasons (which I believe is a Division of Dorman) and it lasted all of about 2 wks before it, too, started leaking. Unfortunately, this was before I had read all about the problems others had with these two brands. Replaced it with the upgrade Motorcraft housing and all is well after several wks and approx. 800 miles...even as the weather has gotten cold. So, pull up the Rockauto website and purchase these parts:

Pt.# RH144 - Lower T-Stat Housing @ $35.79
Pt.# RG614 - Lower T-Stat Housing Seal @ $3.46
Pt.# DY1269 - Sensor @ $21.79
Pt.# SW6146 - Sensor @ $21.79
Reuse existing Upper T-Stat Housing

You'll need the (2) metal clips that hold the sensors in place. Several sources for those:

Ford Pt.# W706800-5303
Dorman Pt.# 800-019
NAPA Pt.# NOE7305034

Don't forget to install a new thermostat o-ring...and may as well replace the thermostat at the same time. Oh...and, might consider replacing the short bypass hose that connects to the water pump while you're in there, too.

Thanks for the reply. Which t stat should I go with from rock auto, as it seems there are quite a few that will work? I assume the new t stat will come with O ring correct. This is my first t stat replacement so please excuse my lack of knowledge.

 

[XLTrunner]

I went with a Motorad #248192 second time around...only because the first one I bought at O'Reilly Auto was some brand name I had never heard of before (only brand they had). Was leery of that one from the start and figured the second time around doing this job was hopefully going to be my last and I wanted to go with a quality thermostat. Nothing wrong with Stant, either. Don't believe the Motorad came with the o-ring, though.

Since this is your first attempt at changing out the t-stat housing, do know that you'll be removing the Upper Manifold on your SOHC engine. That will require you purchase new gaskets for that...as well as the green o-ring that goes on the end of the EGR pipe that sticks inside the Upper Intake Manifold. I don't have part numbers for those...but, Rockauto has them. You do NOT need to remove the throttle body...so, no gaskets needed there. Same with IAC (idle air control) valve that sits on top of your Upper Manifold.

One last thing to be aware of...if your crank sensor wiring harness is draped rather snugly across the top of the lower half of the t-stat housing, you'll need to gain some slack in it in order to lift the t-stat housing upwards enough that you don't break off any of the three tabs on the bottom of the t-stat housing. You can either further remove the Lower Intake Manifold...or, remove the serpentine belt, alternator, belt tensioner and cast aluminum mtg bracket that bolts to the front of the engine that the alternator bolts to. You see...that wiring harness runs behind that mtg bracket and is secured in two places with push clips. Those can be released and will give you plenty of slack.

 

[Bobby Simone]

Did the conversion and everything seemed good. After driving it around there were no signs of leaks. Then I noticed that every two days or so after not driving it, I noticed some coolant on the upper part of the housing and coolant on top of each of the three bolts on the upper housing. Not under the bolt head. I used the correct torque.The leak is coming from the upper housing or above. Def not where the upper and lower housing meet. I readjusted the upper radiator hose where it meets the upper housing and noticed it could of Been a little more snug. My question is if that hose was seeping a little bit, is it even possible for the coolant to end up where it did on the housing or do I have a bigger problem. It hasn't leaked in two days and will check again tomorrow but I tried to follow the leak and it just seems weird coolant could end up on top of the bolts.