Thermostat Question?
Thread Starter
Intermediate
Joined: Oct 2011
Posts: 41
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Thermostat Question?
This subject has been done before but could use some advice. I have 2004, Z06. This my first vette. I live in Southwest Florida. I do not track my car, just a recreational driver. The temp. gauge is always around 210-220. I have the LS6 engine, it dosen't seem to run warm or anything ( I have owed it for only 2 mos.) I have been told that I should consider replacing the thermostat with a 160 or 180 degree. Then, I was told today that it harm the engine in some way. Any advice?
Rick
Rick
Melting Slicks
Joined: Jun 2010
Posts: 2,809
Likes: 3
From: Yorktown Virginia
I would not replace it with anything other than factory, even if you did it will still end up running the same temperature. If you want it to run a little cooler then try cleaning out the radiator fins by spraying water through the back side.
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
The stock thermostat is not 190*. It's something like a 185. So, a 180 won't change things much but a 160 will get the coolant circulating sooner. Then, it's a matter of gettting the air flowing in the rad. Clean it as suggested and set the cooling fans to turn-on at lower temps. Also, change back to a stock size pulley if you happened to have installed an underdrive unit.
Safety Car
Joined: Jul 2005
Posts: 3,572
Likes: 9
From: Jackson Tn
St. Jude Donor '06-'07-'08-'09
I have used and tested all three, 160,180 and the OEM.
I didn't like the 160 in the winter because even with the fans set to get the temp up as soon as you are going down the road the temp would drop to 178*. The fans stop running when you get to @ 35mph. That might sound good but actually it's not. It's not goot for oiling or fueling.
I took each thermostat and tested each on the stove with hot water and a guage to see when it opens and closes.
I don't remember the exact details but it was something like this.
160 first opens @175* then closes at 160*
180 first opens at 195* then closes at 187*
OEM first opens at 205* then closes at 192*
See the first time the open it is to heat the enging up then as the engine runs it closes some but never all the way. They don't "slap" either open or closed. You can see this for yourself with a pan of hot water.
I installed the 180 and my engine runs between 190* and 192*. I'm waiting to see how it works in the hot summer and sofar I think the engine runs better running around 190*. In the summertime the 160 would run in the high 180's. You need software to change the fans settings along with changing out the thermostat.
Hope this helps explain it better.
I didn't like the 160 in the winter because even with the fans set to get the temp up as soon as you are going down the road the temp would drop to 178*. The fans stop running when you get to @ 35mph. That might sound good but actually it's not. It's not goot for oiling or fueling.
I took each thermostat and tested each on the stove with hot water and a guage to see when it opens and closes.
I don't remember the exact details but it was something like this.
160 first opens @175* then closes at 160*
180 first opens at 195* then closes at 187*
OEM first opens at 205* then closes at 192*
See the first time the open it is to heat the enging up then as the engine runs it closes some but never all the way. They don't "slap" either open or closed. You can see this for yourself with a pan of hot water.
I installed the 180 and my engine runs between 190* and 192*. I'm waiting to see how it works in the hot summer and sofar I think the engine runs better running around 190*. In the summertime the 160 would run in the high 180's. You need software to change the fans settings along with changing out the thermostat.
Hope this helps explain it better.
Team Owner
Joined: Jul 2006
Posts: 22,162
Likes: 4,171
From: Kannapolis NC
I have used and tested all three, 160,180 and the OEM.
I didn't like the 160 in the winter because even with the fans set to get the temp up as soon as you are going down the road the temp would drop to 178*. The fans stop running when you get to @ 35mph. That might sound good but actually it's not. It's not goot for oiling or fueling.
I took each thermostat and tested each on the stove with hot water and a guage to see when it opens and closes.
I don't remember the exact details but it was something like this.
160 first opens @175* then closes at 160*
180 first opens at 195* then closes at 187*
OEM first opens at 205* then closes at 192*
See the first time the open it is to heat the enging up then as the engine runs it closes some but never all the way. They don't "slap" either open or closed. You can see this for yourself with a pan of hot water.
I installed the 180 and my engine runs between 190* and 192*. I'm waiting to see how it works in the hot summer and sofar I think the engine runs better running around 190*. In the summertime the 160 would run in the high 180's. You need software to change the fans settings along with changing out the thermostat.
Hope this helps explain it better.
I didn't like the 160 in the winter because even with the fans set to get the temp up as soon as you are going down the road the temp would drop to 178*. The fans stop running when you get to @ 35mph. That might sound good but actually it's not. It's not goot for oiling or fueling.
I took each thermostat and tested each on the stove with hot water and a guage to see when it opens and closes.
I don't remember the exact details but it was something like this.
160 first opens @175* then closes at 160*
180 first opens at 195* then closes at 187*
OEM first opens at 205* then closes at 192*
See the first time the open it is to heat the enging up then as the engine runs it closes some but never all the way. They don't "slap" either open or closed. You can see this for yourself with a pan of hot water.
I installed the 180 and my engine runs between 190* and 192*. I'm waiting to see how it works in the hot summer and sofar I think the engine runs better running around 190*. In the summertime the 160 would run in the high 180's. You need software to change the fans settings along with changing out the thermostat.
Hope this helps explain it better.
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Melting Slicks
Joined: Dec 2003
Posts: 2,857
Likes: 2
From: pawleys island sc
once ANY thermostat FULLY OPENS the operating temp of ANY engine is INDEPENDENT of the thermostat temp rateing PROVIDE that said rateing is LOWER than the engines normal operating temp WITHOUT a thermstat installed.The thermostat temp rateing ONLY determine the temp at which the thermostat is supposed to FULLY OPEN - after that the operating temp is determined by the internal characteristics of the engine's cooling system.
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
No, the thermostat rated temp is the temp it STARTS to open or the highest temp when it's still fully closed. It's not the temperature the thermostat is fully open.
Drifting
Joined: Apr 2009
Posts: 1,898
Likes: 9
From: Morrisville PA
The only thing that will make your car run cooler is if you tune the fans to come on sooner. If you add a 160 thermo, your car's peak temperature while driving will still be the same, it will just take slightly longer to get there.
The thermostat "upgrade" is a waste of $.
230-235 is a bit high regardless. I would see if you have any leaves or objects blocking your radiator from air flow.
The thermostat "upgrade" is a waste of $.
230-235 is a bit high regardless. I would see if you have any leaves or objects blocking your radiator from air flow.
Burning Brakes
Joined: Feb 2011
Posts: 776
Likes: 1
From: spring tx
None taken.i had same concerns and asked forum and gm and shops.they said same thing.200-210 normal driving and hot days in traffic can hit 230s and was told its normal and safe..had a tune recent and fans reset so we will see what it does this summer..
Team Owner
Joined: Jul 2006
Posts: 22,162
Likes: 4,171
From: Kannapolis NC
I'd be concerned if it got to 230 with the fans running. I'd inspect very carefully between the radiator and a/c condensor for dirt or debris. There are times it will get that hot, but mine never has in traffic on hot days. 215 I wouldn't even think about, but 230 is getting close to thinking about.
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
Geeze, keep freaking out about nothing and then listen to the ones who don't know what they're posting....
The stock fan settings are as follows;
Fan #1 on at 226* and off at 219*
Fan #2 on at 235* and off at 226*
Fan #1 comes on with the AC if the coolant temp is above 185* and the speed is below 35mph.
http://forums.corvetteforum.com/1579202267-post3.html
Fan #1 or low fan is both fans in series so they run at a much reduced speed. Fan #2 or high fan is both fans at full voltage so they move as much air as they can.
If it's really hot and you're in slow enough traffic, the coolant will reach 235* before the high fan speed kicks in to help cool it down. So, why is this so hard for some people to figure out? In stock form, the coolant can run to at least 235* on a hot day. That's the way it is and how it was designed, no matter how much hand wringing and forum postings about it you read.
The stock fan settings are as follows;
Fan #1 on at 226* and off at 219*
Fan #2 on at 235* and off at 226*
Fan #1 comes on with the AC if the coolant temp is above 185* and the speed is below 35mph.
http://forums.corvetteforum.com/1579202267-post3.html
Fan #1 or low fan is both fans in series so they run at a much reduced speed. Fan #2 or high fan is both fans at full voltage so they move as much air as they can.
If it's really hot and you're in slow enough traffic, the coolant will reach 235* before the high fan speed kicks in to help cool it down. So, why is this so hard for some people to figure out? In stock form, the coolant can run to at least 235* on a hot day. That's the way it is and how it was designed, no matter how much hand wringing and forum postings about it you read.
Racer
Joined: Mar 2008
Posts: 321
Likes: 0
From: Grandview Texas
Wow! Awesome explanation man. Ive been nervous b/c I SWEAR my old C5 didnt get to 230ish as my new Z has been doing. But the temp cut on/off and A/C relation are spot on with what I found. So Im with ya. Thanks!
Team Owner
Joined: Jul 2006
Posts: 22,162
Likes: 4,171
From: Kannapolis NC
But the FACT is, most don't. I've had 4 C5's and I've never seen a temp over 220. All stock, no tune, stock thermo. Rarely have I seen over 210. If the radiator is cooling properly, the temp will stay lower, the fans aren't running at highway speed anyway, so the cut on and off temps don't help at speed. Even if as you say, nothing is wrong, and it may be true, I'd still check the airflow through the radiator before I gave up. I wouldn't take the car to a repair shop if I saw 230, but I'd be looking around a little.
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
If you say so. But, just because your driving habits don't cause your cars to run hot doesn't mean the fan temps are not that way. The high fan is for hot driving conditions and if GM used 235* for the on temp then the engine must be fine operating at 235*
I usually highway drive with town driving in light traffic so I rarely see much over 200 but when I was sitting in a traffic jamb one night the temps still climbed to 235 before the high fan came on. I've since changed my fan temp settings when I did some tuning.
I usually highway drive with town driving in light traffic so I rarely see much over 200 but when I was sitting in a traffic jamb one night the temps still climbed to 235 before the high fan came on. I've since changed my fan temp settings when I did some tuning.