170 Thermostat C5 YA or NAY
07-22-2014, 01:21 PM
#22
Melting Slicks
I totally get where you are coming from n8dogg - I'm usually on the conservative side when doing my mods, particularly computer tuning. I've wondered more than once if a 170 stat would be better for my truck. It tends to run around 180 during the winter. Fans are of course quite active in the summer - I'm currently turning them on at 193.
Probably more so than the engine's life I'm concerned on the C5 that I bought a couple of months ago its automatic transmission's life. 200 degrees in the tranny is more than I'd like to see, but I see it pretty often. I need to check for debris around the radiator but if I can lower the tranny's temps buy running a cooler thermostat together with turning the fans on sooner that for me is an easier solution that installing a tranny cooler. I know an aux tranny cooler is the better solution but I'm inclined to try the easier solution first to see how it works and then go to the more involved if I think more cooling is needed. I installed an aux cooler in my truck about a year ago before crusing the Blue Ridge Parkway with it and it's 3200 stall converter.
Before doing anything though I need to let it idle up to temp in the garage and with the hand checking the radiator hose method try to figure out what it has in it now. This thing sounds for sure cammed, has long tube headers, Weiand/Lingenfelter intake manifold and what sounds like possibly a Corsa Indy exhaust among other mods. When I bought it computer was custom tuned (not very well) including turning on the fans at 183.
Probably more so than the engine's life I'm concerned on the C5 that I bought a couple of months ago its automatic transmission's life. 200 degrees in the tranny is more than I'd like to see, but I see it pretty often. I need to check for debris around the radiator but if I can lower the tranny's temps buy running a cooler thermostat together with turning the fans on sooner that for me is an easier solution that installing a tranny cooler. I know an aux tranny cooler is the better solution but I'm inclined to try the easier solution first to see how it works and then go to the more involved if I think more cooling is needed. I installed an aux cooler in my truck about a year ago before crusing the Blue Ridge Parkway with it and it's 3200 stall converter.
Before doing anything though I need to let it idle up to temp in the garage and with the hand checking the radiator hose method try to figure out what it has in it now. This thing sounds for sure cammed, has long tube headers, Weiand/Lingenfelter intake manifold and what sounds like possibly a Corsa Indy exhaust among other mods. When I bought it computer was custom tuned (not very well) including turning on the fans at 183.
My Z06 had a 180* stat and ran down the road at 190*. I had the fans programed to start at 195* with high speed at 200*.
What fluid are you running in the transmission? Fluids ability to stand up to temperature will play a roll in transmission life. I'd recommend going to a full synthetic ATF that can withstand higher temperatures.
10-03-2014, 03:06 PM
#23
If the tuner half knew what he was doing then I think it's safe to assume you have a 160* or 170* thermostat. Thermostats will not open at their exact rated temperature, I'd expect a 5* to 10* fluctuation. So if they tuned the fans to come on at 183* for sure you should have a lower rated t-stat installed.
My Z06 had a 180* stat and ran down the road at 190*. I had the fans programed to start at 195* with high speed at 200*.
What fluid are you running in the transmission? Fluids ability to stand up to temperature will play a roll in transmission life. I'd recommend going to a full synthetic ATF that can withstand higher temperatures.
My Z06 had a 180* stat and ran down the road at 190*. I had the fans programed to start at 195* with high speed at 200*.
What fluid are you running in the transmission? Fluids ability to stand up to temperature will play a roll in transmission life. I'd recommend going to a full synthetic ATF that can withstand higher temperatures.
After a little more time with the car I'm pretty sure the cause of my elevated tranny temps are due to a slipping torque converter lockup clutch. (I know it's slipping due to my HPTuners data logs.) I replaced a valve in the valve body which is supposed to apply full pressure to the converter clutch versus the pulse width modulation valve that GM originally put in these. That has not fixed the problem which pretty much leaves me to a leaking solenoid or I'm betting, partly because it will be the more expensive and time consuming fix, a burned up clutch in the converter.
As for your question on what fluid I'm running, after making the valve body change I put Valvoline Dexron VI in the tranny. I'll probably be putting the car up on jackstands and checking that solenoid here in a month or so when the nice vert cruising weather is past us until spring. If the torque converter ends up getting changed, the tranny will have nearly 100% fresh fluid. Not sure that I'll go full synthetic - this thing shouldn't be running nearly as hot as my truck's and full synthetic in it runs about $150...