Leak on top of t-stat housing

[HISSIN50]

Hello,

Vehicle: 2002 Mountaineer 4.0L

I'm hoping for a quick bit of expertise. I noticed a bit of coolant puddled atop the t-stat housing. The sensor in the top of the housing (ECT, I assume) is loose in its fitment. Is that normal? What's the preferred method to seal it up? If there's an O-ring you guys replace in there, what's the best source (or type of material)?

Any tidbits you wanna pass along are welcome.
Thanks a bunch!

 

[gdgiordano]

On my 4L SOHC I had to replace the WHOLE unit.

 

[swshawaii]

Ditto. Very likely another plastic lower thermostat housing splitting at the seams. New aftermarket aluminum replacement below.

http://www.explorerforum.com/forums/showthread.php?t=362922

 

[HISSIN50]

Thank you for the replies!
I didn't snap a shot of it while it was wet, but I outlined/highlighted where it was wet before (using the dampness/stain left from the residual coolant to make the outline). When I noticed the wetness, the clip for the ECT didn't appear to be seated all the way, if it matters. With the clip seated as it is now in the picture, the ECT still wiggles. Is that normal?

Do you still think it's the lower housing? If so, please explain the coolant migration logic (just so I understand).

For ordering purposes, this is a one-sensor housing, no?

Thank you guys!

 

[swshawaii]

ECT sensor should be snug without side movement with the clip installed. It can be rotated. Very likely a split lower housing.
If you feel lucky try replacing the $1 sensor o-ring linked below. Replacement single sensor housing is a Motorcraft RH148.

http://www.napaonline.com/Catalog/C...ptive-Fitting-O-Ring/_/R-TEM407105_0451843410

http://www.explorerforum.com/forums/showthread.php?t=259795
http://www.explorerforum.com/forums/showthread.php?t=355018
http://www.explorerforum.com/forums/showthread.php?t=359557

 

[HISSIN50]

Ok, sounds good. Is the consensus to go to the metal lower? I was thinking that I'd try plastic for now and order the metal version(s) when he has both the upper and lower available for sale. Or should I just got metal lower right now?

Do you guys normally replace the top when you do the bottom (so both are fresh)?

Thanks again.

 

[swshawaii]

Your call on the $149 metal housing. The OEM replacement lower housings seem to be improved with very few reports of failures. Upper housings are usually reused. Basic repair only requires the lower housing, DY1004 ECT sensor, and upper and lower rubber seals. Do not over tighten, factory torque spec is about 7-8 ft/lbs. (89 inch lbs.) for the three M8 lower housing bolts.

 

[HISSIN50]

Awesome. Thank you so much!

One more question. Is that the ECT in the t-stat housing or just the gauge sender?

 

[swshawaii]

That's an ECT (Engine Coolant Temperature) sensor. Earlier SOHC's have the gauge sender.

 

[HISSIN50]

Awesome, thank you!
I know I'm pushing it, but............................. I'm seeing a couple of options for a Motorcraft ECT. I don't suppose you know the correct part number for the single port housing??

 

[swshawaii]

Motorcraft RH148 mentioned in post #5 . IMO, RockAuto has the most accurate fitment guides.

Glad to help in any way, keep us posted with your progress.

http://www.rockauto.com/catalog/x,carcode,1414493,pgname,Cooling+System

 

[HISSIN50]

Motorcraft RH148 mentioned in post #5 . IMO, RockAuto has the most accurate fitment guides.

Glad to help in any way, keep us posted with your progress.

http://www.rockauto.com/catalog/x,carcode,1414493,pgname,Cooling+System

Was that for the Engine-coolant-sensor itself? I'm seeing a couple of 2 wire sensors listed and that's where I'm getting confused.

 

[swshawaii]

You're right, vague descriptions. I believe the DY1269 superceded the DY1004 ECT sensor.
I know for a fact the DY1004 is a perfect fit in the RH148, I used them. DON'T lose the clip.

http://www.rockauto.com/catalog/x,carcode,1414493,parttype,4748

 

[HISSIN50]

You're the man! Order placed. Thank you so much. If I'm ever back in Hawaii, beer is on me!