kgkern01

My car is running about 15 degrees warmer than usual, and the radiator cap doesnt get very hot when the engine is. Could this be the thermostat on its way out?

350 HRSS

That is a toughy for me, b/c I don't know that much about temp. stuff. But I can tell you that I had that problem once, and all I needed was a rad. cap. The thermo would go bad all at once I would think. I am not sure if it goes gradually or not.

Good luck.

BUBBA

Good answer!

kgkern01

Possibly bad radiator cap? I had recently put one of those chrome one's on from Autozone, I'll try going back to the stocker and see how it works. I just bought a 160* thermo today also, so I hope both of these remedy the problem. Where do 160* t-stats usually run temp wise on the dash?

shoebox

Make sure you have an 18 psi cap. Also Autozone is notorious for handing out the wrong 160º thermostat.

kgkern01

I drove up to LS1 Motorsports (aka Quartermile Performance, only about 20 min away) and got the Hypertech stat. The radiator cap was supposed to be for 15-18 psi systems, but I'll switch the stocker back in with the 160* stat in about another hour or so once the engine cools more. (2-3 hours should be enough cool-down right?)

kgkern01

Put in 160* t-stat and then put stock radiator cap back on, bled system, and OMG! It won't go over 165-170* max, I would say more towards 165*.
Is it normal for it to run smoother afterwards? Maybe its just me, but it felt like it pulled a little harder as well. Could the prev t-stat running hot have robbed me of some power? Anyone else notice a difference after installing a 160* t-stat?

94zLT1

your 160 will get you a temp around 185-190(first notch)....180 on cool driving days(little under 1rst notch) but it will still rise fast if not faster in traffic so make sure to back it up with SLP manual fanswitches like me. I love my setup and when it starts rising i just flip the switch in my dash and BOOM instaneous cooling! my Lt1 will never see a temp above 190 again/ oh ya myswell do a TB bypass whole your at it....i used to have major heating problems and i would run 215+ with the stocky...now i love my setup...god is it a difference in power...i remember someone saying that there car ran like a v6 when it got hot...damn shame that is. Hope this helps

Seal

mine hasnt passed 180 once since i got the PCM to turn the fans quicker, with the 160...

but without the fan reprogram, once it went above the 1st line, it never came back down...

a lower fan setting is a must imo, otherwise its pointless

kgkern01

Well, it is only 49* here, and didn't really sit too long, but the temp needle hovered just over the 160* mark the whole way to and home from bar I just met a few friends at tonight. Never made it to the 185* first mark.
I already have manual fans and TB bypass, and before this swap, it ran about 195-200 with the fans on/x-way, didn't matter, now MUCH cooler.
What causes the little power boost? Less KR? More timing adv?

94zLT1

i hear a lot of people like you saying that you run around right over 160..my car doesnt even feel right untill about 175-180(little under 1rst notch) i was wondering isnt that too cold and maybe your LT1 is trying to warm up constatntly at that temp. when i start it in the morning i ease in all the way untill 180-185 b/c i feel like im gonna blow a gasket if i run that cold. colder engines are more suseptable to wear n tear and the most horsepower a LT1 can make is at operating temp and theres no way that 160-170 is operating temp for any car..just trying to figure out how people can run that cold or maybe the sensor for gauge which is in the block is off? IMO the first notch or a little below is the best running temp (180-190). what does everyone else think?

shoebox

IMO, if you run at 160º, that's too cold. Mine runs 175º- 180º with the 160º stat. I put the 180º stat in during the winter, because the engine will stay closer to the thermostat temp when it is colder out.

kgkern01

What causes the slight power boost, was timing being pulled before?? Less KR?

kgkern01

Well, today driving around in traffic the temp was around 175-185 with fans on, so I guess it was just the cold air on the x-way that kept the temp low. As far as how the car feels stronger, I just checked the temp, humidity, and air pressure = 72*, 34%, 29.96 Hg for a relative 119.5% HP or .837 dyno correction factor, and -3453 density altitude. This must be where the small little increase in power is coming from
Thanks for the help!