LS3 Corvette - 160 degree thermostat

[raygun]

Hello, everyone!

I have a 2011 Corvette (base LS3 6MT) with a 160-degree thermostat. I'm trying to find the mechanical thermostat setting in the VCM editor, but I can't find it. Using the parameter navigator to search for thermostat (or even just "therm") doesn't show any results. I have found forum posts indicating that this setting should be in System -> Fans, but it's not listed there either.

Help?

[SiriusC1024]

Re-scale fan desired %.

Disable P0128.

[blindsquirrel]

Also P0116, just because it's a pain in the ass.

[2xLS1]

It's there. System>Fans>Desired % Vs ECT. You can't enable the fans any below 192* anyway with the stock OS. And no need to disable any codes with a 160 t-stat. It will still get plenty warm to not trigger any codes. I've run them for years on all kinds of different GM platforms and never had them set any codes. Even on the Gen 3s where you can enable the fans earlier fully warmed up ECTs will run around 180 if the radiator is big enough.

[07GTS]

updating to the 2 bar OS will give u lower fan temps if u have that option

[raygun]

And no need to disable any codes with a 160 t-stat. It will still get plenty warm to not trigger any codes. .

While I hesitate to disagree, I have a P0128. DFW, kind of chilly but not super-cold. Temp gauge is reading zero, oil temps are normal. Disabling that code brought the gauge back to life. I installed this thermostat and a DeWitt's radiator and Spaal fans about a year ago. This is the first time this issue has presented, but it definitely generated a DTC.

[blindsquirrel]

P0128 & P0116 aren't only about the absolute temp, they look for a specific rate of change (and also something about an 'engine OFF timer', and comparison to IAT, and change of ECT & IAT after engine start, and... some kind of logic to determine if there is a block heater in use??). Change just about anything about the cooling system and it can make either one of those codes freak out. Without any way to adjust the parameters of what they are expecting to see, no thanks, I'll just disable them.

[raygun]

So, in short:

I'll put a stock 195? thermostat back in.

I'd love to see GM - or any other manufacturer - release the source for their ECM firmware for models they no longer support. Since that will clearly never happen, I'll try and keep the smoke firmly entrenched within the magic box.

Thanks to everyone for the insight.

[2xLS1]

While I hesitate to disagree, I have a P0128. DFW, kind of chilly but not super-cold. Temp gauge is reading zero, oil temps are normal. Disabling that code brought the gauge back to life. I installed this thermostat and a DeWitt's radiator and Spaal fans about a year ago. This is the first time this issue has presented, but it definitely generated a DTC.

Have you tested the 160 in a pot of water bringing it up to boil with a thermometer to see when it starts to open? Because you know parts never fail do they. You know there is a way to test parts before assuming it's something else. A properly working 160 t-stat won't keep the temp gauge on zero. I tune for an engine rebuilding shop that installs them in every Gen 3 and 4 they rebuild so in hundreds of uses I've never had a properly working one set a code or had to turn those codes off. And that includes a few of my own vehicles. Just stating my experience with them in a climate pretty similar to DFW

[blindsquirrel]

P0116 & P0128 do all kinds of weird shit like that, even will give substituted values in the scan tool. Voltage will be an actual sensor reading but the *C/*F will be some non-real default number.

[sparroheart]

don't get your hopes too high bringing down a high compression engine temp down with a congested cooling system
the best you can do is 197F in an average 80F weather temp with no A/C
in my experience low temp tstat will help only bringing the temp down as much as your system can aka bigger fan and an efficient rad

[Alvin]

Most cars will not have a issue with that code with a 160 thermostat. It's usually swaps or older trucks with huge radiators that have a issue.

Also not a huge deal to not be able to turn the fans on any earlier than 192. Just 30mph is way more air than your fans can ever deliver. There will still be benefits.

[raygun]

in my experience low temp tstat will help only bringing the temp down as much as your system can aka bigger fan and an efficient rad

I have the big DeWitt's radiator with Spal fans. Cooling has been an ongoing struggle on this car. It typically sits around 205?F . On track, it gets north of 230? pretty quickly, and I've seen coolant temps up to 250?F. In warm Texas summer weather, I wind up having to take a cool-down lap every 10 or so laps.

My car is a base, which probably isn't helping - it doesn't have any of the extra cooling that come with the Z51 / Grand Sport or Z06. I have a Z51 oil cooler in a box that I need to install. Hopefully that will help things. Otherwise, I'm about to the point of getting rid of this car and picking up a GS.

Thanks for the insight!

[raygun]

Also not a huge deal to not be able to turn the fans on any earlier than 192. Just 30mph is way more air than your fans can ever deliver. There will still be benefits.

Do you happen to have a recommendation for the fan PWM curve when running a lower temp thermostat? Mine is shifted ~10? down from the OEM setting. It takes longer to get up to temp but, as expected, it doesn't really help under load.

[Alvin]

You can ramp it on as soon as possible.. Just leave the first cell low or 0 or else the fan will run all the time.

[2xLS1]

You can ramp it on as soon as possible.. Just leave the first cell low or 0 or else the fan will run all the time.

I've heard this but have never seen it occur. There are many stock calibrations that have 40% in the first cell.

[blindsquirrel]

Sure, for relay fans and if State for 0->1 is >40, but not for PWM fans where the State vs Desired table is ignored. I guess it depends on the controller's minimum % for the off to minimum speed transition... the only one I know first-hand is the brushless fans where anything less than 15% is off, 90% or more is full speed.

[Alvin]

I've heard this but have never seen it occur. There are many stock calibrations that have 40% in the first cell.

likely cause the discrete qualifier is over 40.

Still not a great idea. What ever is in the 192 cell seems to effect <192

[village_idiot]

Why not just run a 180, and the car will run temps around 200... Then you won't have to screw with all of the ECM workarounds

[Paulster2]

I have the big DeWitt's radiator with Spal fans. Cooling has been an ongoing struggle on this car. It typically sits around 205?F . On track, it gets north of 230? pretty quickly, and I've seen coolant temps up to 250?F. In warm Texas summer weather, I wind up having to take a cool-down lap every 10 or so laps.

My car is a base, which probably isn't helping - it doesn't have any of the extra cooling that come with the Z51 / Grand Sport or Z06. I have a Z51 oil cooler in a box that I need to install. Hopefully that will help things. Otherwise, I'm about to the point of getting rid of this car and picking up a GS.

Thanks for the insight!

If you have all of the "good parts" in your car and are still having issues with heat, maybe it's something simple you're missing. Do you have the radiator air dam attached below the radiator? Without it, you'll not get the air flow through the radiator because there's nothing directing the air. The air dam provides a high pressure zone ahead and low pressure zone behind the radiator, which forces air through it. Or, if you have a splitter up front to direct air away from under the car, you have to create a different way for air to get through the radiator. If you don't, temps will run high and/or overheat. ... Just a thought.