# Thermostat change **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** engines, lights\ **Created:** [April 28, 2009, 3:25pm UTC](https://community.cartalk.com/t/thermostat-change/29742 "2009-04-28T15:25:38Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Berges](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Berges](https://community.cartalk.com/u/Berges)\ **Post date:** [April 28, 2009, 3:25pm UTC](https://community.cartalk.com/t/thermostat-change/29742/1 "2009-04-28T15:25:38Z")
I installed a new waterpump and thermostat in my 1982 Vette. I went from 190 degrees thermostat to a 160. Is that causing my check engine light to now be on? It has never come on. Also, my rpms are slightly higher than before the repair. Need help. Thanks. Car has 36,000 original miles. ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [April 28, 2009, 3:32pm UTC](https://community.cartalk.com/t/thermostat-change/29742/2 "2009-04-28T15:32:37Z")
I didn’t think a 1982 had a CEL. Is it a charge light or something else? I wouldn’t run a street car on less than 180 degrees. ---
**Author:** ![hellokit](https://avatars.discourse-cdn.com/v4/letter/h/6a8cbe/32.png) [@hellokit](https://community.cartalk.com/u/hellokit)\ **Post date:** [April 28, 2009, 3:32pm UTC](https://community.cartalk.com/t/thermostat-change/29742/3 "2009-04-28T15:32:50Z")
I didn’t know that 160F degree thermostats were even available. GO back to a 190F degree thermostat. For the overheat problem, you need to do other things. Take it to a shop which can do a pressure and leak check, and a cooling system flush. These things may be all it needs to run cooler. ---
**Author:** ![edb1961](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/edb1961/32/122_2.png) [@edb1961](https://community.cartalk.com/u/edb1961)\ **Post date:** [April 28, 2009, 3:35pm UTC](https://community.cartalk.com/t/thermostat-change/29742/4 "2009-04-28T15:35:52Z")
I believe the 82 Vette has a dual TBI setup (Crossfire Injection, AKA Ceasefire Injection). I’m guessing with a 160 degree thermostat the engine is not warming up to the proper operating temperature and staying in open loop mode. Has the mpg decreased? I suggest replacing the thermostat with a 190 degree unit. Just curious, why did you go with a 160 degree thermostat? Ed B. ---
**Author:** ![rocketman](https://avatars.discourse-cdn.com/v4/letter/r/eada6e/32.png) [@rocketman](https://community.cartalk.com/u/rocketman)\ **Post date:** [April 28, 2009, 3:46pm UTC](https://community.cartalk.com/t/thermostat-change/29742/5 "2009-04-28T15:46:30Z")
Why did you go to the 160? Rocketman ---
**Author:** ![mcparadise](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mcparadise/32/32_2.png) [@mcparadise](https://community.cartalk.com/u/mcparadise)\ **Post date:** [April 28, 2009, 4:04pm UTC](https://community.cartalk.com/t/thermostat-change/29742/6 "2009-04-28T16:04:21Z")
The new thermostat has the computer thinking (correctly) that the engine is not fully warmed up. Install the correct thermostat and watch your problems go away. Why did you use a 160 degree thermostat? ---
**Author:** ![Joseph\_E\_Meehan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/joseph_e_meehan/32/21_2.png) [@Joseph\_E\_Meehan](https://community.cartalk.com/u/Joseph_E_Meehan)\ **Post date:** [April 28, 2009, 5:32pm UTC](https://community.cartalk.com/t/thermostat-change/29742/7 "2009-04-28T17:32:05Z")
Why did you go to a 160? stat? It likely will reduce mileage, may decrease power and may cause more engine wear. ---
**Author:** ![Berges](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Berges](https://community.cartalk.com/u/Berges)\ **Post date:** [April 28, 2009, 5:38pm UTC](https://community.cartalk.com/t/thermostat-change/29742/8 "2009-04-28T17:38:03Z")
Thanks for your help. The mechanic, who installed my new waterpump, told me that this 160 degree thermotsat would work fine. I should have insisted on a 190 degree. I watched him install the 160, so now I now know how to replace it. BOB ---
**Author:** ![Berges](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Berges](https://community.cartalk.com/u/Berges)\ **Post date:** [April 28, 2009, 5:39pm UTC](https://community.cartalk.com/t/thermostat-change/29742/9 "2009-04-28T17:39:57Z")
Thank you. I will replace with the original 190 degree. I did notice that it seemed sluggish. The old thermostat is 27 years old. Bob ---
**Author:** ![mcparadise](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mcparadise/32/32_2.png) [@mcparadise](https://community.cartalk.com/u/mcparadise)\ **Post date:** [April 28, 2009, 5:41pm UTC](https://community.cartalk.com/t/thermostat-change/29742/10 "2009-04-28T17:41:14Z")
Don’t use the old thermostat. Go to a parts store and buy a new 190 degree thermostat. ---
**Author:** ![Berges](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Berges](https://community.cartalk.com/u/Berges)\ **Post date:** [May 1, 2009, 11:26am UTC](https://community.cartalk.com/t/thermostat-change/29742/11 "2009-05-01T11:26:13Z")
Bought a new 195? thermostat. This is the same degree as my original thermostat. Check light still comes on and idle is elevated at 1000 rpms. It fluctuates and in Drive will stay at 900 rpms. Still to high. Engine runs smoothly. I disconnected the battery for 5 minutes to see if that would reset the computer that controls the idle and light. Noticed that the spring on the old original 195? was easy to compress with my finger. The new 195? was impossible to budge. Why the difference in tension? ---
**Author:** ![hellokit](https://avatars.discourse-cdn.com/v4/letter/h/6a8cbe/32.png) [@hellokit](https://community.cartalk.com/u/hellokit)\ **Post date:** [May 1, 2009, 12:49pm UTC](https://community.cartalk.com/t/thermostat-change/29742/12 "2009-05-01T12:49:01Z")
A wax pellet melts at the thermostat opening temperature. This lets the 195F degree warm spring open the thermostat valve, allowing coolant to pass through. Your old thermostat no longer has the wax pellet. It has been dissolved in the coolant. [www.wikipedia.com](http://www.wikipedia.com) has this type of information. ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [May 1, 2009, 1:58pm UTC](https://community.cartalk.com/t/thermostat-change/29742/13 "2009-05-01T13:58:13Z")
Check the wiring to the sensors (temp etc.) located in the vicinity of the thermostat housing. ---
**Author:** ![Whitey](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/whitey/32/24680_2.png) [@Whitey](https://community.cartalk.com/u/Whitey)\ **Post date:** [May 1, 2009, 3:06pm UTC](https://community.cartalk.com/t/thermostat-change/29742/14 "2009-05-01T15:06:59Z")
Why did you change thermostats? Which one meets the specifications for your vehicle? Chances are, your Vette can’t reach the proper operating temperature, which will lead to things like reduced fuel economy. Find out what the spec is and install a thermostat that meets that spec.