I have a 1986 T/A. I changed the 195 stat to a 180 stat. I also purchased, but have not installed a hypertech cool fan switch that kicks the elec fan on at 200 instead of 220. My question is.....I talked to a mechanic who told me not to use the fan switch because it causes problems with the closed loop? or something like that and it will increase fuel consumption and cause problem with computer reading o2 sensor or something like that. Is he crazy? I've heard that these are cheap simple fixes to lower the normal operating temp. of our third gens (which was implemented by gm to lower emissions, not considering the wear on our engines and poorer performance) Can somebody please help!! Thanks!!!

 

i think this is in the wrong section but im running the hypertech too n it was the best thing i could have done.

 

At the end of the summer I swapped my single fan for the dual fan setup along with a 180* t-stat and a 200* temp switch. I am VERY happy with the results. Don't worry about closed loop problems. You will still hit closed loop at those temps.

The Hypertech temp switch is way overpriced. You can get one from here for about $15. Part #609-106:
http://www.madvet.com/shop?frame=3.138.944

Yeah this is in the wrong section, but I'm sure a mod would be happy to move it.

 

IIRC you start to have problems with closed loop with the 160 T-stat.... You should be fine.

 

i think i only paid $69 for mine a few years ago

 

I think I read somewhere that many of the closed / open loop temp parameters are at 176, so above that should be ok and not mess up anything...

 

Will that $15 sensor work with an L69?

 

Mine goes into closed loop at 150 degrees or so. Only thing you might notice is a slightly higher idle when it's right on the thermostat temp.

 

Well if it's the single fan setup it will work fine. I'm not 100% sure on the dual fans, but I believe it will only effect the secondary fan or something like that. IIRC the primary fan is controlled by the computer.