Thermostat Housing

[Keola P]

Hi guys, hope all is well. While installing new front tires yesterday, I noticed a bit of evaporated coolant on the alternator. Went home and checked the cooling system to find evidence of leakage between the upper and lower thermostat housing. Did a bit of research here and found it to be a pretty common problem with our first generation ST's. Just left the ford dealership here with all the new parts (hopefully) and will install them when I get home from work later this evening. Any tips or advice before I dive in? Any help would be greatly appreciated. Mahalo in advance..

 

[swshawaii]

Hi Keola! Not a difficult repair, just confined. If you're using the old sensor(s) they will not seal in the new replacement housing and leak. IIRC, o-ring size is 2.5mm thick x 9 mm I.D.

OEM constant tension hose clamps can be a PITA, especially the short water pump bypass hose. Use channel locks or bent nose pliers. Check link below, glad to help in any way.

 

[Keola P]

Hi Steve! Thanks for the info. Would you happen to know if the 05' trac v6 has one or two sensors? I assumed one based on what I read and purchased one sensor o ring. What have you been up to lately? Hope life is treating you well and thanks again!

 

[swshawaii]

My '05 housing had two sensors with only one wire connector. I used the RH148 single sensor housing because I didn't want to buy another $25 sensor to plug the extra hole.

 

[Keola P]

Hi Steve! Thanks for the info. Would you happen to know if the 05' trac v6 has one or two sensors? I assumed one based on what I read and purchased one sensor o ring. What have you been up to lately? Hope life is treating you well and thanks again!

 

[Keola P]

What a major PITA this project is!!! Spent around 4 hrs. working on getting the new thermostat housing in. Space constraints is what mainly slowed me down I think, not to mention needing to run back out to fetch a few tools that I needed to complete the task.



After replacing the sensor and installing the new o ring, I placed the sensor back into the sensor opening in the lower housing and clipped it in (much easier said than done). I noticed that it was extremely loose and I had a hunch it was gonna give me trouble. After everything was reinstalled and replaced, I went to give it a start and returned under the hood to make sure nothing was leaking. Lo and behold, anti freeze was oozing out quite rapidly from the area of the sensor. Tired and beat down, I threw in the towel for the night. Wife is gonna have to take me to work tomorrow.



Did I miss anything when I reinstalled the sensor? Is a new one needed? I have a feeling I may be putting on the o ring incorrectly, but I did not notice any on either of the 2 sensors I pulled out so I have no way of referencing where the o ring needs to sit.



Out of everything I've done with my trac as of now, this has been the most painstaking :banghead: So not looking forward to completing the task tomorrow after work.

 

[swshawaii]

Did you use the 2.5mm x 9mm sensor o-ring size? I couldn't find one and had to buy a Motorcraft DY1004 ECT sensor.



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I hope you're installing the sensor clip correctly. Works only this way and must be pushed all the way into each slot.

 

[Keola P]

I used the one provided by the dealer. A total of 3 were included, one for the thermostat, one for the underside of the lower housing, and a small orange colored one which I assumed was for the sensor. Will try to do more research throughout the day while at work. Again, mahalo for your help, Steve.

 

[swshawaii]

Keola- If the ECT sensor is leaking, do NOT attempt to seal with RTV sealant or teflon tape. I tried, and both methods failed within one week. (Silicone residue seen in pics)

 

[Keola P]

Hi Steve, sorry to bother. I really appreciate the info you been passing along to me. I think my problem may be directly related to the improper installation of the o ring. Is the old o ring on the ECT sensor black and ?flat? looking? Does that need to come off and the new one reinstalled in its place? I just slipped the new o ring over the tip of the sensor, rolled it up until it hit the top flange/lip, and reinstalled. As I mentioned, I placed the retainer clip back on and it seemed extremely loose. Been trying to research the issue and it seems that I?m not alone with this one. Again, sorry to bother you, but you seem to have developed a wealth of invaluable knowledge on our sport tracs. Hope your Sunday is going better than mine. Was just informed that I needed to work a double shift today, so I won't get to finishing what I started until tomorrow...hopefully :cry:

 

[swshawaii]

I think my problem may be directly related to the improper installation of the o ring. Is the old o ring on the ECT sensor black and ?flat? looking? Does that need to come off and the new one reinstalled in its place? I just slipped the new o ring over the tip of the sensor, rolled it up until it hit the top flange/lip, and reinstalled.

BINGO! Old flattened o-ring MUST be removed and replaced in the same location. Once the clip is installed, sensor should fit snug with no rocking movement in the hole.

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[Keola P]

I hope that's the issue, Steve. Gonna tackle it tomorrow after work. Its only been a day since I last drove my trac and I already miss driving it. I'll keep you posted.

 

[swshawaii]

Although cramped, sensor can be pulled out and re-installed without removing any other parts. Disconnect the sensor wire connector first. Should be a quick fix. :supercool:

 

[Scott Tanner]

you need a new o-ring on your old sensor.... BTDT..

 

[Keola P]

Just got home and attempted to work on this leaky sensor issue with no luck. Reinstalled the o ring, properly this time, by removing the old one and replacing it with the new. To my dismay, there's still a lot of play with the sensor in it's mounting hole.



I opted to use the housing with the one sensor mounting hole instead of the two hole housing since the other sensor is non functional (besides being a plug). Could it be that the mounting holes on the lower housings with the single mounting hole be bigger than the housing with both sensor holes? I tried placing the sensor with the old o ring back into the old housing and it fits snugger than they do in the new housing with the new o ring. This is driving me freakin' nuts.

 

[swshawaii]

Keola- Baffling. I and many others have used the RH148 single hole housing but replaced the sensor because of poor fit. The sensor should "snap" into the housing, much like a spark plug boot feels when installed on a plug. Your best option is buying a new DY1004 or DY1269 ECT sensor. Avoid aftermarket, and use the OEM sensor to assure proper fit.

 

[Keola P]

Steve, thanks for all your help. I think the issue has finally been resolved. Well, for the most part. The main issue was indeed the o ring. When I was attempting to place the retainer clip back onto the sensor, guess what happened? Yup, I dropped it. Luckily, I had the clip from the other sensor I could use since I got the single mounting hole thermostat housing. Attempted to slip it on a second time and guess what happened?. Yes, sprung out into the engine, AGAIN!! No where to be found. I was so, so frustrated.



Went to the dealer today to check if they had the clip in stock, they said it needed to be ordered and cost around 11 bucks per clip!! Checked all other parts stores (napa, o'reily, car quest) and no one had it. Bought a universal clip and needed to make a few adjustments to make it fit correctly. Trac runs fine for now... temp remains cool, no leaks. Still gonna have to track down a retainer clip though. Gonna see if I can rip one off at an auto recycler. If worse comes to worse, I'll get one from the dealer. The clip in there right now is just a temporary fix.



Mahalo for all your help again. Will try to post pics when the job is completely finished!!



Aloha!!!

 

[swshawaii]

Keola- Email me your mailing address, I have an extra one. This trick is mentioned in the Bengrosser repair link. Tie a string, floss, or mono

fishing line to it before installing. A needle nose vice grip is the perfect tool for installation. I'll just stick the clip in an envelope if you want it. :supercool:

 

[Keola P]

Should have done the monofilament trick. Makes perfect sense. Email sent..