Since my radiator has developed a leak, I removed it this evening and will be taking it to my local radiator shop for a hopefully reasonable cost repair. Although my exisiting thermostat has been working fine on my 223 I-6, I was wondering since I have the coolant drained and hoses removed if I should go ahead and swap it out for a new one? I try to live by "if it ain't broke, don't fix it" but would still like feedback. Thanks. Steve

 

If it has been in there awhile, I would change it. Just be sure to buy a high quality thermostat. Lots of junk parts out there now.

 

I have had the truck for 5 years so at least it's been in there that long. I already have a thermostat that I got from Autozone that I carry as a spare.

 

I'd leave sleeping dogs lie if it is working properly. All the hoses in good shape?

 

Me too
all the new stuff is made from poor quality

 

It's really not hard to change and thermostats weren't built (even back in "The Day") to last. Get a good quality thermostat and change it. I remember in the 60's and 70's changing thermostats for summer and winter.

 

Yes, the hoses look real good. Thanks for the inputs.

 

If it aint broke don't fix it

 

Update: Well it looks like I should have changed it out. Installed the radiator, added fresh coolant, water and with the radiator cap off, fired her up and watched to see if I needed to add water after the T-Stat opens; it didn't happen for my mech gauge kept climbing and I shut her down when it reached 200. If the stat was working, it always has opened at 180 and the temp drops back down to 160. I'm still going to test the stat I removed plus the new one I'll be installing. Odd how it decided to apparently fail that is unless I did something wrong but don't know what I could have done wrong.

 

Should be a fairly common part #? Not unobtanium anyway. It's true a lot of new parts available are absolute trash today, but ebay and NOS parts houses can provide good ole' U.S.A. made stuff 1900-1980 for not too much money delivered right to your door.

 

Installed upside down? That's about all you could do to make it fail. NAPA "Premium" thermostats are still pretty good quality, and open wider than some. p/n THM 532080 looks right for your engine.

 

Hello Ross. The stat that failed was the one that came with the truck. I already had a Stant 160 stat that I got from Napa that I carried as a spare. When I placed them in the pan for ops check, the Stant opened around 165 and the faulty stat finally decided to open after the water was boiling hard. It used to open around 180. Technically it still works but it seems to take a whole more heat in the water for it to open and I'd rather not keep using that one.

 

Maybe the system wasn't purged?

 

Yep, toss it in the trash. 160 may be OK in the summer, but 180 is usually a better all around stat.

 

One more question; for reinstallation on the 223 I6, my shop manual does not specify which order if the gasket is installed first on the block followed by the stat prior to bolting up the housing elbow. Does it matter? It does specify this for V8s. Also, what type od adhesive can be used for the gasket? Silocone or RTV ok? Thanks.