When I did my head gasket, I had my wife go get a thermostat for me at Auto Zone. I should have specified what kind, but didn't. She got the cheapest one, probably the Auto Zone brand. I'm guessing the 195 degree. Anyways, on the highway, or just moving down the road, it does fine. Needle points right at 195. But if I'm stopped, it will get up to 230. Haven't seen it get higher than that. The fan usually kicks on and cools it down, or at least keeps it from going higher. Is this normal? If I put in a good 180 degree thermostat, that's not going to keep it from climbing while at a stop is it? Anyways, is it normal for my temp to climb that high at a stop on a 70 degree day? Matt

Yep it's normal. You can run a 180 stat if you want but she will still heat up if you are not moving fast enough for the airdam to keep flow across the rad. These cars will go up to 230 or so even at 20 degrees outside temp. That is because it is not a belt driven fan. If the fan(s) are working OK you are fine. There is a lot of info here about lower stats and fan switches and I have experimented with all the different setups, but they all come with drawbacks. The stock setup from an engineering point of view is, I believe, the best.

195 on the highway seems alittle high. Usually mine will run about 170 on the highway and can get up to 220 in traffic in the summer.

If you simply lower your stat without getting the fans on earlier then it will still get hot when sitting in traffic. Hell, my car with a griffin rad and spal fans gets up to about 210 idling in traffic with the air on full. The temp drops to about 170 after cruising for a few minutes though.

195 on the highway wouldn't be high if I have a 195 degree thermostat right? Matt

I have a 195 also and yes that is still high, cruising at around 60 or 70 mph you should drop down to the 170 range. Chech your air dam, it could be damaged.

Now if my car ran cooler than what the thermastate was rated at I would think that the unit has defective. I was always lead to believe that the unit was supposed to maintian the water temp at 195 and if it got cooler then 195 it closed so that the coolant would get hot, then the unit would open when it reached 195 there fore keeping the engine temp at 195 all the time.

Yeah, the thermostat is designed to maintain a minimum temperature. Cooling fans help to maintain the operating temperature.

So what you guys are saying is once warmed up, it is impossible to run cooler than what the thermostat is rated at right? My 92 rs is completely stock and in the middle of the summer in 90 degree weather it will read just above the 160 mark on the freeway. In traffic it will rise to about 220 or so, but on the freeway it will cool to around 170. Just because the thermostat is rated at 195 doesnt mean it will not go below that. Sitting still the thermostat will open at 195 and the fans dont come on until around 225, so usually it will run between there, but on the freeway the wind cools the engine down considerably. IMHO I feel that 195 is too hot for the freeway.

I've NEVER heard anything like that. On every single car I've ever owned, and I've owned a lot, I wound upreplacing the thermostat's on them all, and maintained te cooling system. My engines ALWAYS ran at the temperature that the thermostat was rated at. I'd say that if you have a 195 degree thermostat and you're only running at 160 or 170 on the highway, your thermostat is sticking. Sure, you can have air blowing on your engine, but that's not going to keep it cool all by itself on the highway. If your thermostat were locked shut, you'd overheat on the highway in a hurry even when it's 20 degrees outside. If your thermostat is rated at 195, it should close at 195 and your engine should stay at that temp. I know if my engine were running 30 degrees cooler than the thermostat rating, I'd replace that sucker! Matt

thats what i have thought for a few years now

with three stock 350 tpi thirdgens, every single one ran close to 220 with the 195 stat, in traffic after a few minutes the temp would climp up untill the drivers side fan came on and the temp would hold the temp untill i would start to move again..

now with my current car i put it a 180 stat just to see what would go on. during highway runs the guage read in the middle of the beginning and 220...

when in taffic for over a few minutes it will start to move towards 220 but then i start to move again and it cools right back down..

so right now it seems i will stay cool without even using fans unless i get into a traffic jam, thats what the manual swithc is for on my passengers fan, or i could just wait untill my drivers fan comes on by itself.. either way my lowered my noram operating temp down a few degrees..

What????!!!! OMG, that cant be possible, you have a 180 stat and you run 160 on the highway, dude something is wrong with your thermostat, lol jk. By the way, with the 195 stat what did it run on the highway?

i put a manual switch in as well because i think my fan temp sweitch is broken becaus eit turns the fans on at 240! so whenever i'm idling i'll switch my fan on so that i never go higher that 220!

humm i put in a 180 stat the best kind that advance auto had...

we all know that the stock temp guages are not 100% correct, but if i had to take a guess i think it runs close to 185....



with my stock cooling system the car would run according to the guage 220 or just a tad below on the highway...

that seemed to be the stock temp on all three of the 350 tpi thirdgens i have had...

I put a mechinical guage in. Much more accurate. On the hwy it reads from 195-210. In town it drops to 195. I have a clutch fan. No switchs to worry about.

That's different!! Usually these cars run a little cooler on the highway. Oh well, more power to ya...

Well, I had cooling system problems last summer and found out the following. I have a 1984 Z28 with a warmed over 355 on NO2. When driving on the highway (75mph) at night last summer (85*F) I looked at my temp gauge and was suprised to see 220* I have a 160* stat with (4) .200" holes drilled in the stat body and my eng. always ran at whatever the outside temp is. If its 85* out the gauge will read 185 to 190* at highway speeds. The first thing I did was take off the rad cover and remove all the bugs ect, ect, that was covering 1/3 of the top of the rad. Went for a road test and the eng ran just a little bit cooler. Hard to tell on the stock gauge. Anyhow my next move was to check the air deflector and it was still there (original) but when I pushed on it, it took verry little effort to push it to the rear. I thought to myself "whats it like at 80mph". Went out and bought a new one (which is much stiffer) for $18.00 with the discount. Installed that honey and went for a road test. Eng cooled down to 200*. Still no cigar OK, next move was to check V belts and they were adjusted proprly. Next move, check the stat. Removed the stat and hung it with a wire in a pan of water and turned on the burner. Watching the temp gauge (wifes) it just keeps going and going up to 220* and nothing. It wouldn't open. The only thing that saved my eng were the (4) .200" holes I had drilled into the stat body. Whew !! I bought a new 160*stat (the most expensive I could find $10.25) drilled the holes and checked it out in that same pan of water. It worked but I did find out that a 160* stat starts to open at 150* and is fully open at 160*. Went for a road test and everthing is back to normal
Well anyhow, I hope this story might help someone out.

Auggie

That's kewl!!!!!! No literally!!!!

Those little holes saved the day. Maybe I should drill a few myself.

I'm doing my thermostat tomorrow i bought a auto zone fail safe if it fails it fails open.

Same here. Except i have a mechanical fan that runs all the time.

Have you realized your posting on a thread from 7 years ago

Yes.

Well since he brought this back form the dead I do have a question along these lines. I tried to buy a 140 thermostat from O'Reilly's the other day and they told me that they don't sell them for thirdgens. I could of swore I bought a 160 about 7-10 years ago. Can nayone confirm if there is one and where I could get it from?

Do you want a 140 or a 160 ? you stated both.

opps...160...my mistake

Who ever told you that is a retard. Funny i have one in my car and i can open up a summit book and there right there on page 203. I dont have a computer controlled a car but i hear the lower thermostat screws with the computer and you need a new chip or something along those lines.

My "84" is computer controled (CCC carb) and have not had any problems.

Auggie

Okay Summit sells them. I don't remember changing a chip in my car. I will check them out.