The Corvette Kid

I have a 2009 LS3 engine in my 61 Vette with the factory computer. If I change to a 180 degree thermostat do I need to have the computer reprogrammed to turn the cooling fan on at a lower temp. or doesn't it matter. Thanks, Bob

JasonS5555

Hey Bob,

The fan turn on temps don't HAVE to be changed. The effect is this. When you're driving at speed, the airflow will keep the temp at ~180. When moving slowly, the fan turn on temp will determine what water temp you see before the fans turn on and cool.

Jason

S'vette

I went from the stock 187 or whatever it was to the 160 and when it was the stock stat I saw 195/+ temps. Now I see 180ish but really no lower. Stopped of course it goes up. The thing I had read before was that the oil temp needs to get to like 212 degrees to burn out moisture and what not. Right now with winter months here of 50 - 60 degrees it wont get that hot unless I romp on it a bit. Which I actually do alot. I have of course other mods and a tune to reprogram the fans but going to the 180 for the LS3 was the right thing to do. What was the stat in there before? I think a few years back they went to the 187 stats from the 190 or so for the LS3, so you definately needed to go atleast 187/180 stat. I think your stock fan settings will be fine with the lower stat.

EuroRod

The oil only needs to be warmer than the ambient air temp to eveporate moisture. Ever see steam coming off a pond? Same principle. Of course, the warmer the oil temp, the faster the moisture will evaporate.

S'vette

Well then thats good as the oil once warmed is always above ambient. I had read the 212 degree thing somewhere. Either way I get above both levels when I romp on it.

The Corvette Kid

Thanks guys, Great information. I bought the LS3 engine brand new from Chevrolet and the instruction sheet says the ECM turns the cooling fan on at 210 degrees, so I wasn't sure how that would work with the 180 thermostat, but I don't what thermostat comes in a stock LS3 and I was thinking a 160 would be too low. Thanks again,Bob

JasonS5555

Hey Bob,

The other question of interest is how big is your radiator and fan setup? Are they stock fans?

Jason

S'vette

I beleive the LS3 comes with a 187 stat. And to add to what Jason asked, how much front air is hitting your radiator and all compared to a C6? If not as much air is hitting it then the 180 stat should be a good one to use. Either way 187 or 180 or even 160 you should be fine. The 160 wont have you running at 160, I see 180+ in 50 degree weather right now with my 160.