Temp sensor---seal question

[John Zuber]

2004 ST with the one (single) sensor in the thermostat housing. Have some minor coolant seepage between the low and upper housing, and same with the temp sensor area. Went ahead and purchased a new housing kit, thermostat, small lower hose, and o-ring for thermostat. Honestly, after reviewing the project section and seeing how it all works I probably only need a new o-ring for the thermostat and new seal for the temp sensor. Regardless, I don't have a new sensor o-ring and calling Ford parts I can only get the o-ring by purchasing a new temp sensor for $40. Will a generic o-ring work, or is this seal more that a simple o-ring design? Has anyone just replace the upper seals (thermostat o-ring and sensor o-ring) and had it successfully seal? Is the lower seal also an o-ring that can be replaced, or is a new lower housing a requirement?

 

[swshawaii]

John, majority of the time the lower housing is splitting seams and requires replacement. Did you buy OEM parts? If so, I've read the RH-148 ECT sensor hole is slightly larger than the original. I did this repair several years ago, and recall trying several different o-ring sizes without success and always had seeping coolant. Replacing with the Motorcraft DY1004 (DY1269) ECT sensor did the trick. Maybe rent a refundable coolant pressure test kit first?

 

[John Zuber]

I purchased this housing...still in the mail. See link.



Bought the OEM / Ford Thermostat and thermostat o-ring.

Are you saying I should expect a housing with a sensor hole that won't fit my existing/original sensor? What is RH-148 ECT? Who and what part are you referring to? And the DY-1269 sensor is larger diameter than what I currently have? Thanks..

 

[swshawaii]

RH148 is the single hole OEM Motorcraft lower housing. Not familiar with the aftermarket CarQuest replacement, but your pic appears the same as the Four Seasons part linked below. When you remove the ECT sensor, you will find the o-ring compressed with a flattened edge. I'd wait until part arrives and test fit the sensor. Good luck.

 

[Todd Z]

Yes, you can match one up, BUT I believe Felpro makes the gasket, The aluminum one comes with the new o-ring separate so yes.



Todd Z

 

[John Zuber]

Ok, got all my parts from Advance Auto...and I'm taking them back. The Motorcraft thermostat is in a beat-up box, and the numbers on the thermostat don't match the package. The housing kit includes a thermostat (which I'm sure is generic), and the title clearly implies that a thermostat is included, but yet in the "questions and answers" it says it doesn't include the thermostat. I wouldn't trust the thermostat, but the housing looks good. Nonetheless, it's all going back. I called my Ford dealer and the thermostat o-ring and the bottom housing seal ring are both available for only a few dollars. Assuming I can match up a new o-ring for the temp sensor I should be able to re-use my old housing, which still looks new on my vehicle. I'm only getting slight seepage from the thermostat o-ring and the sensor o-ring area. I'll keep the new housing-to-water pump hose, and rebuild with new seals and a new thermostat and I should be good.

 

[Todd Z]

Fingers crossed, Good luck.



Todd Z