I changed my T-stat last week with a new Superstat, and I did the drill technique. It only lowered my operating temp by one notch on the guage. It sits at the hash mark right under 200. Plus, when I stop the car, the fans run for a few minutes after the car is shut off. The PCM is calibrated for a 180* t-stat. I would think that being less than 40 degrees outside and drilling the stat, the car should run in the 170-180 range, and not the 190-200 range. I siphoned the antifreeze out when I changed the stat, and put every drop of it back in after I was done, so it can't be low, unless the LIM is leaking, which it doesn't. ...I'm confused here.

I dont think it should lower your operating temp that much, but it prevent a lot more overheating and take more time to get up in temp.

Someone correct me if im wrong. :?

180 thermo means it should run at 180...

My thoughts exactly. Plus being drilled, I figured a few degrees cooler, plus taking longer to warm up. It shouldn't run just a few degrees cooler than the stock 195. I'm thinking I got a crappy t-stat that'll need changed again.

with a 180 thermostat, you will only run at 180 degrees while moving, when your computer still turns the fans on at 195, so when your not moving its still heating up to 195.. you need an upgraded computer to get the true 180 affect

My PCM is set for a 180 stat, but the guage stays at the mark right under 200, even while moving...and when I shut the car off, the fans are running, just like they did before I changed the t-stat. I had the PCM in for a week or two before I changed the stat.

the guage can not be trusted for acuracy either, it is only there for reference, i wouldnt trust anything but a REAL accurate guage or a scantool to get a reliable reading from

Hey mikey, you may not want to here this, but I thought you should know. My 00 LeSabre runs at 183* - 187* all of the time. It may get up to 197* on a hot day in heavy slow traffic but cools down to 183* as soon as it gets clean air. The fans only come on at 216* after a very long idle with the car standing still on a 110* scorching summer day. This is all with the stock 195* t-stat.

On my 02, It stays about two notches below the 200 mark most of the time. Itll heat up when i have to do a highway entrance since some of our ramps in michigan are super short. Fans are usually on when i shut the car off.

To help clear this up.

A thermostat of 180 degrees means that the thermostat does not fully open allowing unrestricted flow of the coolant until 180 degrees. This way the thermostat is designed to maintain 180 degrees.

To complicate this is the fact that our fans do not run until the specified temperatures programmed into the pcm. (In this case for Mikey it is 180).

The thermostat is partially closed until 180 degrees or more is obtained, meanwhile the car generates quite a bit of heat while being restricted by the thermostat. And his fans are programmed to come on at 180 degrees.

Then there is gauge accuarcy to be considered. The mentioned inaccuracy of gauges and using a scan tool for a postive number is the best way to be positive..

I am currently running a 180 degree thermostat and am also running about 190, however I have confirmed my gauge to be +5 degrees with a scan tool. As well with the 3.4, I've also noticed plenty of extra heat when accelerating and am looking into it myself. Make sure you remove the engine cover. It helps a lot.