Has anyone had trouble removing the three small flanged bolts that hold the thermostat? Mine have never been touched from new (1994). My local garage didn't want to do it for fear of breaking them. I wanted them to install a hotter thermostat (205 deg) but they effectively said the existing one (stock 192) is good enough.

 

The PSD runs better with a 203 stat in it. I replaced mine a couple months ago and had some problems. I broke the the head off of one bolt. I just drilled out the bolt, tapped and dyed another bolt to fit.

About a month after I did that my waterpump went up and I got the original housing back.

The 203 stat can only be found here for our trucks. The ones you buy at the parts house are not the correct ones.

DIESELSITE 203* Thermostat

 

Farm is 100% right on the bolts. I too snapped a bolt on the t-stat flange, but it was due to torqing them too many times. If you re-use the ones that are in there, make sure that you get a good bead of RTS on the neck and seal it right the first time, then you wont have to worry about redoing it.

 

i am assuming his is a 94 dont that mean hes already got a 203? "Until 1996, all 7.3L Powerstrokes that were manufactured used an International water pump and an International short stem 203o thermostat . In 1996, Ford changed to a lower degree 195o"

 

Your right, 94 and 95's came stock with a 205* stat. Its only a upgrade for the 96 and 97's to get a 203* stat from diesel site.

 

I got my thermostat from NAPA. They said it was for a '95. But it sounds like it's no different to what I've already got. The part no. is 371-203 so it might be 203 deg after all. I also went to the local Ford dealer and they said theirs is 192! I'm having trouble staying warm in the winter - even when using grill inserts. The needle on the idiot gauge shows it's operating in the normal range but only just - it barely moves off the pin. I do get heat so the thermo is working. Maybe this is just the nature of the beast. My engine is the earliest PSD. When I bought the truck I paid $500 extra to get the new engine.

 

Yes you have the right stat for your truck. Ford has now changed all their stats to a 192. thats too cold! you want the 203 in there. Bolts might break and they might not. But if they ahve never been off then that means your water pump has never been changed either. How many miles on the truck?

 

Remember those stock gauges are basically idoit lights. Also, check of the condition of your thermostat neck. Sometimes they get pitted/rusty so I might be a good idea to replace it too.

 

If you do decide to change the Thermostat spray some "PB Blaster" on the screws. The housing forms a little lip all around the base of the housing and fill it up and let the screws soak for a couple of days.

Use a 6pt. socket and use steady constant pressure on the screws until they break free. They will sound like a gun shot. It's important to keep the socket, extension and breaker bar STRAIGHT.

Use a big breaker bar. (I use 1/4" stuff adapted to 1/2") it's easier to maintain the position and pressure. Use anti seize when replacing them.

Rog

 

just makin sure in case i have to do it!! thanks

 

another good tip is to take a long punch or even long extension and put it right on top of the bolt than smack it with a hammer. once or twice. that shocks it a bit and breaks things loose a little. Doesn't always work but helps.

 

Thanks everyone for your comments. Mileage on my truck is 215000 km. So it looks like I've already got the 203 thermo. then, and it's working. Probably best to leave it alone.

 

if its never been changed chances are its not working. If you are having trouble getting heat in the cab or engine operating hot enough its not working. probably stuck partly open.
I run 200 degrees no matter how cold it is unless I am idling.

 

Quite right. I suspect it's not operating 100%. I'll change it out after all, using all the advice kindly offered.