Thermostat Housing 2000 Explorer Eddie Bauer 4.0 SOHC - Leak, bolt, & removal issues

[3xowner]

I have searched and read many posts and Youtube videos regarding this housing, common issues of the leak, and removal procedures...

HOWEVER, I can not find a video with the proper steps (even the Ben Grosser link) that truly identifies the set up that I have. I will try to add pictures soon.

I say that first as this housing is the one that does have the screw in sensors (not clip retained) and the bolt guides for the upper housing to the lower housing are not the same, that is there are no guide protrusions from the lower housing upwards that fit in the upper. Mine has both upper and lower having there own guides pressed in.

I attempted to remove the upper housing to inspect the thermostat O-Ring as the leak truly seemed to be coming from around that higher level portion. When I attempted to remove the back bolt from the upper, it seems to simply spin without truly loosening upwards. I wonder if one or both pressed guides for that back bolt have broken their seal and are spinning in the plastic.

I reassembled everything and tightened the upper back up and now still a slow leak from the drivers side. So the leak now seems to have moved from the front and back of the upper / lower join to the left side. It is still a slow leak.

OK, so to give a complete background on this it goes as follows:
at 64k the previous owner appears to have had the dealer replaced the thermostat for general maintenance. He was awesome with maintaining the vehicle and using the dealer, I have all receipts. But now I think by it being done back then, that it set up what I am experiencing now, that is the leak around the upper / lower housings and possibly damage to the back bolt guide.

The leak has been around now for about 4 - 6 years. It really was never that much and I always have topped off the coolant every 1-2 months or 2,000 miles with maybe a quart. But now I read more and more about this topic of the housing I now am wanting to get in there (and now am better set up at home to do the work). 3 years ago, the dealer quoted $750 total - 3 hours of labor... now I see the dealer wants $480 for my housing kit alone (upper and lower).

I got the sense from the forums that this complete housing assembly (upper lower and sensors) had been superseded however the dealer says it has not. If the new version (sensors are clip retained) works, then I do believe that it is cheaper than mine (even at the dealer).

I found a great 1999 down at the salvage yard which was exactly my set up and the parts were in great shape. I practiced the disassembly and the tough parts (which info and videos out there do not demonstrate) is that there is one harness that I had no choice at the junk yard to cut that ran over top of the lower housing and I had to unbolt a fuel line on the passenger side. I still had not removed the intake manifold nor remove the alternator. I got the upper and lower housing out finally and they are in great shape, there is no scarring on them from say a previous leak. I believe that I can use these if needed (just need new gaskets). Nice that it was only $5 and best of all, got to practice. The harnesses on these Explorers, 99 and 00, do seem packed in there and I hope someone has some advice they can give.

In the end here, I guess my raised points are as follows:
1.has this set up (screw in sensors) been superseded?
2.if back bolt guide is damaged, how best to remove? can I get whole housing out in one piece if need be?
3.any info on this set up and the wiring harnesses?
4.any recommendations for aftermarket?
5.any other advice?

thanks in advance !

 

[swshawaii]

Lower thermostat housing design flaw is the welded plastic seams that inevitably split apart and leak. In addition, earlier housings had threaded ECT sensors and gauge senders that almost always fracture when loosened. A less common issue such as yours is usually due to long term leaking and corrosion when bolts in the upper and lower sleeves will seize and spin in the housings. LAST thing I would do is install a salvage yard replacement. Regardless of appearance, due to age and heat cycles, it will not last long unless it was a replaced housing from the donor. IMO your best option is upgrading to the RH148 housing with upgraded sensors. If you're tempted to use the cheap aftermarket Dorman or Four Seasons parts, do some searching, many horror stories regarding fitment issues causing leaks. GL

http://www.explorerforum.com/forums/showthread.php?t=239493

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

 

[swshawaii]

Sorry, meant Motorcraft RH144 lower t-stat housing if you have TWO sensors. Check RockAuto and Amazon pricing.

 

[drdoom]

Four Seasons no dam good.

 

[XLTrunner]

Four Seasons no dam good.

Ditto on the Four Seasons. I believe I read they are a Division of Dorman...another make I'd stay away from. Avoid the temptation to buy the cheaper replacements. You'll regret it...as I did when my Four Seasons lasted all of 4 wks before it started to leak. You've gotta go with the Motorcraft upgrade. Lower housing, seal and both sensors came to about $85 (delivered) from RockAuto a year ago. Sensor clips are $3-$5/pr. I wouldn't install that used one you pulled off the '99, either...unless, you love the idea of re-doing this job yet again.

I truly don't know how you removed the complete t-stat housing without removing the upper intake. Especially, considering it's near impossible to manuever the lower portion of the t-stat up and out without breaking off a couple of the plastic tabs (which are now brittle from age) on the bottom and having them fall into the intake.

As for the harness that runs over the top of the t-stat housing, it's best to remove the belt tensioner, alternator and alternator mtg brkt so you can access the clips that hold it to the block behind all that stuff. It then gives you enough slack to move the harness as you remove/install the housing.

 

[3xowner]

Thanks, yea I hear you on this. Why is it the dealer is saying no upgrade / supersede part then?

I am familiar where the back seem splits... I don't suspect that with mine yet. However, I may need to condemn mine soon on the upper back bolt spinning.

BTW, before I touched it, I lost pressure during a pressure test and seen the leak near the front. Now after my first attempt, pressure seems to be holding fairly well....

I hate to be this way, but I am going to run it and watch how things go. See if it still leaks, what the rate is, where it runs to, etc. Try to practice the removal again at a junk yard as the harnesses were unbelievably difficult... bring a few more tools, swivels and small wrenches.

Is there an official statement from Ford on upgrading the housing though? Seems that this upgrade really is the case, but want to see Ford's official stance.

 

[3xowner]

Also, curious if there is a outline of years and housing designs used, especially on the Explorer 4.0 SOHC .... obviously this job is roughly 20% different than a Ranger and appears much more difficult.

 

[3xowner]

more info on the leak, seen coolant usage and near front of engine in Fall of 2012 at 122k. Found coolant leak at housing in summer of 2013 at 129k. Currently at 147k.

So everything's been reasonable and manageable for 25k over the last 3.5 years. Maybe have used 10 gallons mixed so far... or roughly 40-50 bucks worth. This is why now since its holding pressure better that I want to see how things go. In the end my goal is to maintain this machine for maybe another 1-2 years and 10-17k.

Hoping then next summer to snag my friends loaded 2014 Explorer XLT when lease is up... nice that he over estimated his mileage and the buyout is really a decent deal

 

[3xowner]

I got the lower housing out of the junked 99 explorer intact.... without removing intake manifold nor removing the alternator, bracket, nor belt.

Because this was a junked vehicle, I tried everything not to cut the harness that goes across and to the bottom of alternator (?) but I just was not able to get at clips for it so I cut that small harness. I also had to unbolt a fuel line from the passenger side behind the lower housing's outlet neck.

As I would not want to cut the harness on my own nor get so deep into removal of alternator, bracket, belt, intake, etc.... that is why I am really researching this. I want it fixed right, but truly only if it makes sense for what not doing it yet maintaining it vs the cost and effort of me doing it.

 

[drdoom]

I pulled the harness from the CKP sensor, cleaned it and put some new loom and tape on. Did the repair then reconnected the harness Much easier.

 

[3xowner]

Well, it's been 350 miles since I tightened the bolts on the upper thermostat housing (2 in front torqued and rear close as possible) ....

So far so good.... Not leaking coolant and level has remained consistent. Pressure test seemed good.... Held for 2 minutes and then only slightly lowered afterwards.

Around the upper / lower join, it still is just barely wet, but nonetheless it's not leaking anymore.

I wanted to outline this as this remove and replace is a pain and costly for parts. When people hear of this leak, the assume the whole housing needs replaced. I recommend to take some time and truly see what is the real case. I am chalking this whole thing up to a thermostat replacement done at 65k and only later needing retorqued.

It was good to get the front two bolts out and clean them up. I washed down the areas with water to attempt to get the coolant scarring off.

Of course I am going to keep monitoring this as now the pressure should be at 16 psi and hope the next weakest area to spring a leak. After 1 k miles more, I probably will post again.

Now I feel better to spend my money instead on tires

 

[3xowner]

Update on this

The leak returned after 2 months and around 700 miles. I had picked up an expedition during that time and spent time on that.

Now getting back to this housing job. I must say, I had not found any exact examples or videos on the same set up I have. Many wires (crank sensor wire is the worst), tubes and hoses further restrict access to an easier removal / installation. Overall I don't think that intake needs removed but the removal of the alternator and its bracket makes things much more easier and provides more room for installation.

I will outline more on the job soon.

 

[LoquetusofBorg]

My 98 never had that problem, lucky I guess. I put the metal housing in mine, ebay about 179 bucks. I put that in and never had a problem with the wires getting in the way. I forget, your back bolt that screws into the block on the thermostat housing, isn't that a helix setup in the block? If it is just get a helix kit and re-do it? You may have to oversize the hole just a little but you can get a bigger helix to fit in there with the same diameter bolt to screw in it?

 

[3xowner]

It was the back bolt on the upper housing going into lower. Seems that one (of the three wells in lower housing for upper bolts) does not have what I will call a drip hole under the female sleeve. My sleeves are all flush, unlike many in videos at YouTube. The sleeve separated from the lower housing and allowed the upper housing to leak along that area.

I would think that perhaps the original owner replacing the thermostat set this issue up years down the line.

On mine, the crank position sensor wire lays right across the lower housing, right in between both coolant sensors. It is best to remove alternator and bracket, then pop off the wire's two retaining push clips that are mounted on a thin bracket right behind the alternator bracket. This will give enough slack in the wire it work it around the lower housing with sensors still in it. Also, having the alt & it's bracket out of the way, gives great space to install it easier and safer (protecting those 3 fins in lower housing).

 

[LoquetusofBorg]

You are right about the lower housing as I broke one of those little dam tabs off while removing the original plastic lower housing. Good luck!
Robert