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How to: Change thermostat 1991 - 1994 Ford Explorer w/pcs

mr cribb

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The following pictures are on a 1992 Explorer, build date of 12/91.... your belt tensioner may or may not be in the exact same location from a following comment I received below.

I looked for a how to on here and really didn't find anything comprehensive, so here is my how to write up. I did find bits and pieces, but when I searched I noticed a lot of confusion still lingering about. The only part I found was the info on how to tell if the thermostat was stuck shut.

How it came to be that I needed a thermostat: on 10-31-11 my temp gauge was almost pegged on the 'NORMAL' it was on the L of it. My truck doesn't run that hot ever. It was always on the R. Well my truck would only cool down by the cold air rushing through the radiator, and as soon as I was stopped it would spike back up again. THIS IS A STUCK THERMOSTAT. Here is what you need:

Thermostat (pictured is a 180* factory is 195*, I opted for the lower temp because it isn't overly cold in the winters here)
CIMG0481.jpg


and an O-ring gasket:
CIMG0480.jpg


DO NOT USE ANY GASKET MAKER.... it will cause issues later on (this is the big thing I found while searching) EDIT: Gasket maker instructions are noted in a comment below if you decide to use it.

Now after you remove the intake tube you should see this:
CIMG0482.jpg


You DON'T HAVE TO remove the belt tensioner assembly but I found it to be easier for me to access the 3rd water neck bolt. (If you choose this route it is a 17mm socket to remove the bolts, to get the bottom bolt you will have to move the tensioner to the side with a breaker bar and 16mm socket) Here is what it looks like removed:
CIMG0478.jpg


The 3 water neck bolts are 10mm. Have something to catch the antifreeze when it pours out. There is a pin on the thermostat, and I read somewhere to have this pin in the 12 o'clock position so I did this. Be careful during assembly to not over tighten the bolts as they could become stripped. I didn't use any blue thread locker on the bolts during my assembly but you could.

After the installation of my 180* thermostat, my temperature gauge reads on the O of 'NORMAL' then cools to the N. The heat is just as hot as it was with the 195* to me, but then again I kept my temp turned down in the truck with the old thermostat.
 


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willindsay

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Edit your post and put
so that the pics show up in the post so it's easier for people to follow.
 




SwaintaN

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good write up, but yeah x2 on the post the images as imaging post. some people will tell you that you can use the gaskets maker on the edges that its better for it. they used to make a cork board gaskets for it, since the age of the ex is OLD theyve stopped making a lot of the gaskets, especially now there is 655 (o rileys says so lol) different kinds of gasket maker
 




mr cribb

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Edit your post and put
so that the pics show up in the post so it's easier for people to follow.

good write up, but yeah x2 on the post the images as imaging post. some people will tell you that you can use the gaskets maker on the edges that its better for it. they used to make a cork board gaskets for it, since the age of the ex is OLD theyve stopped making a lot of the gaskets, especially now there is 655 (o rileys says so lol) different kinds of gasket maker

Thanks guys, I've been on here almost a year and really didn't know how to post pics.

As for gasket maker I did buy some, but didn't use it after reading the links I did find saying not to use it, due to it could cause clogging or gumming of the radiator later on and since my radiator is new as of 02-2011, I didn't want to screw that up :).
 




SwaintaN

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just to throw out some options out there so people know when reading your thread. if your worried about heat issues you can use the 160* tstat, that is what i run, it runs at NORMAL N, no issues and have been running it a few different winters and summers now with the ohio clients.


gasket maker, when using it, its a very thing line you smoothed out with your finger, that helps avoiding the clumping and getting where its no suppose to be.

good write up.
 




mr cribb

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just to throw out some options out there so people know when reading your thread. if your worried about heat issues you can use the 160* tstat, that is what i run, it runs at NORMAL N, no issues and have been running it a few different winters and summers now with the ohio clients.


gasket maker, when using it, its a very thing line you smoothed out with your finger, that helps avoiding the clumping and getting where its no suppose to be.

good write up.

Thanks, just trying to help others if they have any questions on how to do this particular job. I have received so much help from here, that I wanted to return the favor.

Hmm didn't know about the 160* stat, I went to AAP so all my options were was 195* and 180*. I probably could've checked Oreilly's and AZ but I prefer the friendliness of the local AAP here.

Also good to know on the gasket maker instructions. I did put an EDIT above to let folks know to see the following comments on the gasket maker.
 




SwaintaN

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just a tid bit, the 160 has to be asked for, its considered a "performance" part not OEM replacement.

submit it to the How To Threads
 




willindsay

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Not sure Iwould go down to a 160 T-stat the engine is designed to make peak power and fuel effeciency at a certain temp and I have read on here that 160 is just too cold.

I personally went with a 180 T-stat but I think next go round I'm gonna go with the stock 195 to see if I gain anymore MPG.
 








Xeek

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i bought a stant myself and threw it away when i saw there was no weep hole. then bought the stock motorcraft one for $15.

and i didnt really have issues with any of the bolts.
bottom bolt: was a deep 10mm 1/4 drive, 1" extension and a 1/4" ratchet.
the left bolt: 10mm deep, 1/4" wobble, 4" extension, ratchet

all i did was take the belt off, but i dont think i had to
right bolt: easy with anything
 




Jason94sport

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If you get the upgraded superstant it doesn't have a weep hole. It's designed to not have one. I have that in 180 degree. I stripped the bolt as well. I did not take the tensioner off. I should have. I spend 2 days trying to get that 1 bolt in. Also there's different tensioner locations on some models. My 94 was at the bottom left of the engine. The 93 has it at the top. The 94 was much easier to change the tstat.
Also use a razor blade & carefully dig the groove out on the housing. I had a bunch of gunked up gasket material in there & someone did put sealant on it too. Had to scrape it off the face of the flange to get it all smooth. May as well hit it with some black or gray paint while it's out too. Mine was all flaking off.
 




mr cribb

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If you get the upgraded superstant it doesn't have a weep hole. It's designed to not have one. I have that in 180 degree. I stripped the bolt as well. I did not take the tensioner off. I should have. I spend 2 days trying to get that 1 bolt in. Also there's different tensioner locations on some models. My 94 was at the bottom left of the engine. The 93 has it at the top. The 94 was much easier to change the tstat.
Also use a razor blade & carefully dig the groove out on the housing. I had a bunch of gunked up gasket material in there & someone did put sealant on it too. Had to scrape it off the face of the flange to get it all smooth. May as well hit it with some black or gray paint while it's out too. Mine was all flaking off.

Updated first post with your info Jason. Thanks for that tid bit of info.

I agree with the painting part... I'm holding out until I HAVE to rebuild my engine, and if Turdle is still spraying at that time, I'll hit him up then.
 




mr cribb

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I started not to take off the tensioner, but the 3/8 drive wasn't going to fit, and I had the wiring harness in the way as well.

As Xeek said you can get it w/ 1/4 in drive stuff. I just didn't have any handy at the time.

Hey Xeek... your post was #1900 for you...
 




Roadrunner777

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There was another thread worth talking about here. The OP had a loud tick relating to t'stat opening after replacement. It appears it was thermal expansion of the housing and was lessened/resolved by slightly loosening the bolts, like 1/8 turn. If I were to do this job again, I might put a thin layer of anti-seize on the bolts and on the face of the housing.

If I were a preventative type person, I might do the thermostat, belt, tensioners, and fan in the same job.
 




Jason94sport

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Updated first post with your info Jason. Thanks for that tid bit of info.

I agree with the painting part... I'm holding out until I HAVE to rebuild my engine, and if Turdle is still spraying at that time, I'll hit him up then.

The tstat is in the same location on all 1st gens. The tensioner is not. It's easier to get to the tstat when the tensioner is located in the bottom left side of the engine.
 




mr cribb

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The tstat is in the same location on all 1st gens. The tensioner is not. It's easier to get to the tstat when the tensioner is located in the bottom left side of the engine.

OK thanks, I corrected my update.
 




mr cribb

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There was another thread worth talking about here. The OP had a loud tick relating to t'stat opening after replacement. It appears it was thermal expansion of the housing and was lessened/resolved by slightly loosening the bolts, like 1/8 turn. If I were to do this job again, I might put a thin layer of anti-seize on the bolts and on the face of the housing.

If I were a preventative type person, I might do the thermostat, belt, tensioners, and fan in the same job.

I recall reading that one. And yes anti-seize is prob a good idea, unless you use the bigger rachet :D, I didn't use any anti-seize on my job.

Wise idea on the preventative part, but I would probably do what you suggested if I was changing the water pump, since you have to take all that off to do that particular job.
 




akbossman

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Thanks Every body

Just did a change on my 91 Navajo with 256,000 miles. I removed the tensioner because I started to strip the left side hole because the bolt wasn't going in straight. Now still no heat so I'm thinking H2o pump. Long story now its winter Doh! :navajo: :rolleyes:
 




mr cribb

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Just did a change on my 91 Navajo with 256,000 miles. I removed the tensioner because I started to strip the left side hole because the bolt wasn't going in straight. Now still no heat so I'm thinking H2o pump. Long story now its winter Doh! :navajo: :rolleyes:

Is the water pump leaking? You'd notice that. Look for leaking from either the weep hole or around the gasket area.

I would change the heater core. In the lower 48 it's a $23 part, might be a tad bit more up there where you're at. It's 4 bolts 2 hose clamps, and prob 15-20 min of work. I think it's the EASIEST part to change.
 


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cklinejr

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I just did this on my 94' didn't have to remove any pulleys or anything (radiator was already out)

I was able to get at em with my 3/8" drive stuff, not sure where 1/4" would be needed. I used a u joint on the pass side bolt behind the idler, worked perfect.

Thanks for the pics, it helped with the mental prep.

Whats everyone's thought on the 180* stat? I did a search and couldn't find Anything definitive to go 180 over the stock 195 (so I went with 195)

-Charles
 




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