Don't spend the $50+ dollars on a hypertech. Just modify your stock one. It is very easy and works just as well. I have had mone running for several months with no problems.

Here goes:
Remove the t-stat from your truck (two 10mm bolts). Using pliers, press down and twist off the upper part of the t-stat. (Fig A) This will free up the assembly. The springs are pretty strong. (Fig B) The goal here is to make the t-stat open sooner (at a lower temp) so you need to add something to the small hole in the main housing that will force the t-stat to open sooner. I used a typical BB to do this. The "rod" (Fig C) that fits into the housing goes in about 1/4" So whatever you insert in there needs to be smaller than that. A BB worked fine and I didn't take the time to look any further for other items lying around. Reassemble the t-stat. Note: Be prepared for alot of coolant to flow out of the water pump when you remove the thermostat.

<img src="http://www.jade-co.com/tstat.jpg" alt=" - " />

 

Couldn't we just replace the springs with some less powerful ones that would allow the wax in the tube to expand sooner?

 

Thanks for the mod Big Tex, how much did the BB lower the engine temp? ON my 5.3 is runs about 205-208 degrees or so on the temp gauge. I read somewhere that even with the 160 stat the engine is still around 180 degrees.

 

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