I bought a GM 170* thermostat, and want to swap it out with the 195*, to help keep things running cooler. My concern however is, if I run the car on a cold day, will the engine warm up sufficiently with the lower temp 170* thermostat?

Thanks

 

Everything that I've read shows that 170 is the best. Not too cool, not too hot.

I've always run a 180, and I've never had any cooling issues.

 

How were u able to get a 170* thermostat? Iv read that they keep your car in the ideal operating temp for TPI cars, and no human being working at any parts store iv talked to knows that 170* stats exist haha. If its from GM i havnt been able to find anything through searches, would u hapen to have a part number? thanks

 

I run the GM 170 thermostat in mine and everything works just fine. I also installed the new fan switch that will turn the fans on sooner to work with the cooler thermostat, no problems.
The GM part # is 10220957 Larry.

 

I put a 180* stat in today along with a cooler fan switch. I'll report results later this evening.

 

Oh yeah. The 180 stat makes a big difference on my car. I'm not all that happy with the new fan switch though. Still working on that one.

 

Just curious, but what's wrong with it?

 

I'm curious too, what is wrong with it? Which one did you get and what temp range?
I bought Hypertech's switch, I like it, comes with a factory style plug end so you don't have to hack the factory wire harness, I bought the (on at 200 and off at 185) switch, seems to work real well with the 170 thermostat, when I am moving down the road the fans don't even run at all, seems to be doing what it is supposed to in my case. Larry.

 

I inititally purchased a Covette temp switch that ened up not fitting my block (now I have to do an RMA with madvet.com). When I got the old one out to replace it however I saw some damage and decided I needed to replace it anyway... even with just the stock replacement. I ended up finding one that was rated for 20 degrees cooler than the stock one (don't recall the part number, sorry) and went with that one.

So long story short, the engine's normal operating temperature is much cooler now than before with the new stat but the fan is not kicking on at a lower temperature than before. As far as I can tell, it is starting at the same temperature as before. I need to look at this more too. Its only been driven 8 miles since the change.

 

Cadillac, did you order part number 609-106? That's really odd, because I had noticed people recommending it in past threads (including me, even) and saying it would work.

But just last week I ordered that exact fan switch, got it early this week, and it bolted right in like the stock one. It's working just fine for me .

If you don't mind me asking, exactly how would it not fit? Would it go in but not thread, would it not even go in the threaded hole, etc.? I'm just curious because I've recommended this fan switch to other people on other boards.

 

YES! That is the part number from Mid-America Motorworks switch I got. The wiring harness did not match. Other wise, it actually did fit the block. Sorry for not being clear about that. I supposed I could have changed the wiring harness but I didn't want that hassle.

I think this is the switch I should have ordered:

Rodney Dickman Switch

Not sure how it is different. Looks the same as the one I ordered for twice the cost.

 

Yep, that looks just like the Hypertech switch I put in. The Hypertech was also more money but it has the correct plug end for the wire harness so I did not have to hack on the harness. Larry.

 

The connector for the fan switch should have worked. Does the connector for your stock fan switch look like this:



Did you buy the "fan switch conversion harness" from Madvet.com, too, or just the fan switch? Sorry to bother you again, but I just want to make sure I fully understand.

 

I just bought the switch... not the harness. That is what the harness looked like but the end of the one I got from madvet didn't fit it. The two couplings just looked different.

 

Ok, I gotcha now . I didn't buy the harness, either, I was just curious. Thanks for answering my questions, I just wanted to make sure about why it didn't fit for you.

 

I have a 170* in my RS (lo3) and it weather below 40* it won't go into closed loop so I put the stock one back in during the winter.

 

I've had a 170 thermo in 0 degree weather and the car warms up just fine. However, I would suggest for keeping the car cool to get a fan switch that you can control. Like in the article on thirdgen.org. T into the (I belive green, dont quote me on that)and hook it up to one side of the switch and ground the other switch's connector. That way you can let the car warm up to whaterver you want in the winter, and than turn on the fan. OR you can run it all the time in the summer. It works great. Belive me, your car will warm up, they are designed for that. If you want a good thermostat and still have it work right get a MR.Gasket
4364-- 180 thermo.

4363 is the 160 thermo which I bought for summer.

The good thing about these guys is that they are high flow and stay open all the way unlike the stock ones which get affected by the preassure and thats why there are a lot of problems for many people on here.

 

I guess I should have been more specific. It will go into closed loop but after driving for a few miles it will cool off so much it goes back out of CL.

 

You have my interest now. I run a 170 thermostat in my 350 Iroc and never had that problem in cold weather. Mine stays in closed loop, at any rate, what is the actual temp where the computer switches from open to closed loop? I thought it was somewhere in the 150 degree range. Correct? I will have to hook the scan tool back up and keep an eye on it for a while. Larry.

 

I have the 170* in my RS with 305. And compaired to my Z28 with a 350, the RS takes a lot longer to warm up than the 350. i don't know why. maby it is becasue of the lower compression. but even after I let it idle and get up to temp It will still cool way down on a long trip. And if I don't let it warm up first, sometimes it will never go into closed loop wile on the highway.

 

150, if you get the chip I belive it lowers a bit, but am not sure.
My car gets to about 180 and drops down to 170 and kinda oscilated there unless you go driving like crazy to where it will climb, on a warm day 100degrees , to about 200. Trust me, when you pop that baby in you'll love that 220 is not even in the mix
If my car ever hits 220, i feel like I redlined it.

 

yeah forgot to menchion (sp) I have the hypertech chip also.

 

I still run the stock chip in mine which is why I was curious when it went to closed loop. When the scan tool is hooked up it either says open loop or closed loop, I never really paid any attention as to what temperature it switched over. Once it is in closed loop I have never experienced it going back to open loop in cold weather even with the 170 thermostat. I figured it was somewhere around the 150 mark, I was unaware that an aftermarket chip would change that setting. With my own chip programming I assume I can also change that setting myself? Thanks for the headsup on such a small detail I would have overlooked. Larry.