What temp do fans turn on?

[Houston Ben]

I got my truck in for exhaust and got to really drive it for the first time. I only drove it for approx 6 miles and when I checked the temp with code reader it said it was at 212 degrees but the fans were not on. I am hoping the tuner didn't turn thoes off.

[Houston Ben]

I'm asking because I have seen 190 degrees and 220 degrees and want to know which is correct.

[Indian113]

I have mine set at 220 then my fans kick on and off at 190. That's the way my tuner did it . I've never had a problem in heavy traffic at 90+ degrees outside. It doesn't take long for my fans to cool off my radiator.

[RaceAGMC]

Mine come on at 184 and off at 177. I have a 160* T-stat if that makes any difference. I see around 200 on hot days sitting still.

[BR3W CITY]

Originally Posted by RaceAGMC

Mine come on at 184 and off at 177. I have a 160* T-stat if that makes any difference. I see around 200 on hot days sitting still.

160* is really too cold to run in these engines 95% of the time. The 180* stat is about the lowest you usually go, with MANY high hp cars keeping the stock t-stat. These engines are designed to run in the 195-212* heat range for "optimal" output. The increase in technology and efficiency, and the decrease in tolerances means cars are burning hotter, making more power and using as much of the fuel as possible, minimizing unburned fuel.

Running the ls engines too cold will decrease power, and be detrimental to performance and longevity, barring a handful of circumstances in which it would be useful. In many cases, your making the engine spend more time trying to warm up and preventing it from completely doing so.

If you are switching to an ultra low stat to help with cooling problems, you need to look at upgrading your radiator and fans, or checking for some mechanical problem causing heat buildup. Things like water wetter, changing tranny coolers, and adding capacity can all help with cooling problems. Ultra low temp thermostats are a bandaid, only making you feel like the problem is solved, but actually masking the symptoms.

[dec010974]

I agree with brew city. Most of the gm trucks such as the tahoes , suburbans Silverados operate in stock fashion, around 220 degrees Fahrenheit. LQ4s, LM7s, LQ9s use the thermal efficiency theory better than the sbc ever did. If it was mine , 205 degrees Fahrenheit would be my number. If the fans aren't operating as programmed, chec with ur tuner and check the relay wiring.

[Houston Ben]

Cool, thanks for the replies guys!

[Houston Ben]

I know, old post but just thought I would update, on stock setup my small fan turns on at 231 and turns off at 193 Fahrenheit.

[littlevictories]

freaked me out for sure when my shti didnt come on till 200

[solidaxel]

My 5.3 comes on at 208* and off at 194.5* with a 190* Thermostat.
The only times it will come on is with the A/C on or sitting ideling for a period of time, runs on the freeway at 199* with the A/C on and 197* off, HD 3 core rad new, electric fan(1), I hope everything stays there in a few months when it stays over 100* every day!!

[crazy longhorn]

205 on/ 195 off....Painless controls on a dual 14" elect fan setup (carbureted). The stat is 187, IIRC... My 02 runs 205-210 in summer weather, I plan to run the same way with the 5.3 in my 69, but don't have enough time on the swap to say how it goes...Longhorn