Thermostat, T-stat housing, bolts

[hunterjamison]

So last week I gunned the engine to turn left onto a busy highway and was pleased at the G's. Next thing I know theres little puddles of green where I park. Opened the hood & saw pools of coolant on the manifold. While checking for leaks, took a flashlight and found what I thought was a rat's nest on top of manifold. This was just the remains of a bag put in place to absorb engine heat protecting the intake. Using a mirror and light I found the seeping leak on the rear of the lower thermostat housing. Ran it very carefully and short distance for a week, replaced it for $53 motorcraft from Oreillys plus $11 coolant. Was going to buy a t-stat at the same time since I had it all out but didn't want to pay $18 extra! When I pulled out the original t-stat it was in 2 pieces. Put it back together the same way inside the new lower housing. Bolted down & reconnected hoses, temp sensor. Added 1 GAL coolant to reservoir and started engine. BIG LEAK from ECT sensor! The port on the new housing is larger than the OE. Called FORD, sevice tech said, "Yup, see that one alot. We just put in a bigger O-ring." Luckily my neighbor was heading 12 blocks to ACE hardware and I didn't have to ride my bike in the rain, 41 deg F. Took the sensor w/ me to compare o ring sizes and purchased two for 25¢ each. Had to push it down hard, was afraid of breaking the plastic top, but was able to insert the metal retainer into the housing and the larger size O-ring kept a tight seal. Took a test drive and everything was uneventful. Got right up to temp as usual and the heater got going just as it always does, like a furnace! Still, I was worried my thermostat might be acting stupid if it is separated, so I bought a new one for $16 at Oreilly's. Murray Plus. Next day drained a gallon of coolant and while draining, torqued lower housing bolts to 89 ft-lbs. Think I #@ed up here, because one of them broke off. No need to put in a new stat now! Gotta take it all apart again anyway. Got my unreputable Easy Out kit ready and took it apart (again). Got lucky-the bolt was 1/8" above manifold! Vise Grips got it. Replaced with a cheesy different headed bolt, no OE bolt available, but got it tight enough, w/ enough washers. While apart I installed the new thermostat and gasket. Everything is operating exactly the same, temp right below half way on the gauge, the best part is NO LEAKS!
My questions are:
-Ft-lbs or In-lbs!!??
-Where do I get a replacement for the 75mm 6X1.0 8mm flange bolt I busted?
-Why did my tstat work properly when in 2 separate pieces?
-How do I repair the old housing? There has to be a way to seal the little pinholes in the glued seam on these. Has anyone seen a more durable replacement? Not plastic?

 

[tlutz211]

I'm assuming that you have the sohc 4.0? I have a 97 so my sending units are threaded so I never ran into the o ring problem, but I researched for weeks and there is no after market other than the plastic... This beeping said, I bout my unit from autozone cuz they had a lifetime warranty on it and I feel like its gonna fail eventually... Bad design on Ford for this one... Perhaps we should fab up an aluminum/magnesium alloy unit and get rich off of their screw up. What do u say? Lol

 

[Exproblems]

[QUOTE=hunterjamison;2948384Was going to buy a t-stat at the same time since I had it all out but didn't want to pay $18 extra! When I pulled out the original t-stat it was in 2 pieces. Put it back together the same way inside the new lower housing.>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Finding the old t-stat broken in 2 pieces didn't alarm you? The 4.0L Ex T-stats are a one piece deal that uses a single rubber o-ring seal, thats it! Why get cheap for a lousy $18 for a new t-stat after having removed the upper and lower housings? Do it all in one shot while you are in there.

>>>>>>>>>> Still, I was worried my thermostat might be acting stupid if it is separated, so I bought a new one for $16 at Oreilly's. Murray Plus.>>>>>>>>>

Lot of extra work and worry for nothing, should have replaced it earlier, especially when you found the old one broken into 2 pieces.

>>>>>>>>>>Next day drained a gallon of coolant and while draining, torqued lower housing bolts to 89 ft-lbs. Think I #@ed up here, because one of them broke off. >>>>>>>>>>>>>>>>>

You got it right, you f'd up here! The t-stat bolts get tightened down to 89 inch lbs, not 89 ft lbs! No wonder one of them snapped off like off like an old man with a new set of dentures biting into a frozen "Slim Jim" snack.

>>>>>>>>>>>>>>>>> Replaced with a cheesy different headed bolt, no OE bolt available,>>>>>>>>>>>>>>>

Just get one from a junk yard.

>>>>>>>>>>but got it tight enough,>>>>>>>>>>>>

Hopefully not 89 ft lbs again.

>>>>>>>>>>>My questions are:
-Ft-lbs or In-lbs!!??
>>>>>>>>>>>>>>>>>

Already answered for you, it's inch lbs! The t-stat housing is made of plastic.

>>>>>>>>>>>-Where do I get a replacement for the 75mm 6X1.0 8mm flange bolt I busted?>>>>>>>>>>>>>>>>>>>>>>>>

Junk yard!

>>>>>>>>>>>>>-Why did my tstat work properly when in 2 separate pieces?>>>>>>>>>>>>

Good question and you got lucky, but I'm more concerned with why you would re-install a known, broken, inexpensive t-stat the first time you had everything apart?

>>>>>>>>>>>>>>>-How do I repair the old housing? There has to be a way to seal the little pinholes in the glued seam on these. Has anyone seen a more durable replacement? Not plastic?>>>>>>>>>>>>>>>>>>

You should be able to buy the upper or lower t-stat housing from a Ford dealership parts dept or get a used one from a junk yard. I'm not happy that Ford used plastic engine parts either, but you have to know the right torque setting for the bolts that hold these parts down before you crank on them. You would have been better off asking what the right torque setting was before you started working on it, not after.

 

[hunterjamison]

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<Lot of extra work and worry for nothing, should have replaced it earlier, especially when you found the old one broken into 2 pieces.


You got it right, you f'd up here! The t-stat bolts get tightened down to 89 inch lbs, not 89 ft lbs! No wonder one of them snapped off like off like an old man with a new set of dentures biting into a frozen "Slim Jim" snack.

>>>>>>>>>>>>>>>>> Replaced with a cheesy different headed bolt, no OE bolt available,>>>>>>>>>>>>>>>

Just get one from a junk yard.

>>>>>>>>>>but got it tight enough,>>>>>>>>>>>>

Hopefully not 89 ft lbs again.

>>>>>>>>>>>-Where do I get a replacement for the 75mm 6X1.0 8mm flange bolt I busted?>>>>>>>>>>>>>>>>>>>>>>>>

Junk yard!

>>>>>>>>>>>>>>>-How do I repair the old housing? There has to be a way to seal the little pinholes in the glued seam on these. Has anyone seen a more durable replacement? Not plastic?>>>>>>>>>>>>>>>>>>

You should be able to buy the upper or lower t-stat housing from a Ford dealership parts dept or get a used one from a junk yard. I'm not happy that Ford used plastic engine parts either, but you have to know the right torque setting for the bolts that hold these parts down before you crank on them. You would have been better off asking what the right torque setting was before you started working on it, not after.>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Thank you for the quality replies, I thought I was smart 6 years ago. My fix worked a long time. Now seeping a little bit. Going to replace and install the way it should have been done last time. (might as well change the thermostat again.) Still having a hard time finding a replacement for that broken 75mm 6X1.0 8mm flange bolt. Also wondering if anybody has heard of a pad ont top of the intake manifold to disperse heat in these models. Thanks.

 

[Drewmcg]

The bolts for both the upper and lower thermostat housing are available from any Ford dealer. There is, indeed, a metal aftermarket housing available at a premium on ebay. Lots of references to it on this forum; here it is:
https://www.ebay.com/itm/01-11-Explorer-Mountaineer-B4000-4-0L-Aluminum-Metal-Thermostat-Housing-Kit/182767928621?fits=Make%3AFord&hash=item2a8dd1452d:g:m1sAAOSwKE9Z1SKR&vxp=mtr . Even includes new bolts!

 

[miker104]

Junkyard is the best option for the long bolts. IIRC the dealer wanted some ridiculous price.

 

[Joshua11]

I got my bolts at Lowes