# Car temperature guage fluctuating **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** sensors, overheating, coolant, engines, eclipse, mitsubishi\ **Created:** [May 7, 2009, 2:33am UTC](https://community.cartalk.com/t/car-temperature-guage-fluctuating/30150 "2009-05-07T02:33:48Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![lucasm822](https://avatars.discourse-cdn.com/v4/letter/l/b5e925/32.png) [@lucasm822](https://community.cartalk.com/u/lucasm822)\ **Post date:** [May 7, 2009, 2:33am UTC](https://community.cartalk.com/t/car-temperature-guage-fluctuating/30150/1 "2009-05-07T02:33:48Z")
after successfully replacing my clutch and reassembling my 2003 eclipse RS, i now have a problem. When driving, the temperature gauge fluctuates between halfway and the quarters of the way up. its all good-ish. unfortunately, when i turn the heater on, it runs hot for a little while, and then gets very cold. tonight i almost went into the red on the temp gauge when i turned it off after it got cold on me. what should i be looking for? HELP!!! ---
**Author:** ![Cougar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cougar/32/21348_2.png) [@Cougar](https://community.cartalk.com/u/Cougar)\ **Post date:** [May 7, 2009, 2:40am UTC](https://community.cartalk.com/t/car-temperature-guage-fluctuating/30150/2 "2009-05-07T02:40:41Z")
Check the coolant level and make sure it is full. There may be a air bubble causing the heater problem but there may be head gasket problem and exhaust gases are getting into the coolant and causing the trouble. Have a block check done to see if that is happening. ---
**Author:** ![lucasm822](https://avatars.discourse-cdn.com/v4/letter/l/b5e925/32.png) [@lucasm822](https://community.cartalk.com/u/lucasm822)\ **Post date:** [May 7, 2009, 2:42am UTC](https://community.cartalk.com/t/car-temperature-guage-fluctuating/30150/3 "2009-05-07T02:42:30Z")
how can i check for an air bubble? i drained and removed the radiator hoses to gain better access to my transmission, could that have cause the air bubble? also what would cause a head gasket problem during a clutch replacement? ---
**Author:** ![cigroller](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@cigroller](https://community.cartalk.com/u/cigroller)\ **Post date:** [May 7, 2009, 2:47am UTC](https://community.cartalk.com/t/car-temperature-guage-fluctuating/30150/4 "2009-05-07T02:47:31Z")
You probably just have air still trapped in the cooling system. If you don’t have any air bleeders, I’d just - carefully - run the car from cold to hot with the radiator cap off for a few warm up cycles while tapping & squeezing on the upper radiator hose. ---
**Author:** ![EllyEllis](https://avatars.discourse-cdn.com/v4/letter/e/f14d63/32.png) [@EllyEllis](https://community.cartalk.com/u/EllyEllis)\ **Post date:** [May 7, 2009, 4:27am UTC](https://community.cartalk.com/t/car-temperature-guage-fluctuating/30150/5 "2009-05-07T04:27:50Z")
I think the above post is correct. ---
**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:** [May 7, 2009, 10:19am UTC](https://community.cartalk.com/t/car-temperature-guage-fluctuating/30150/6 "2009-05-07T10:19:54Z")
i drained and removed the radiator hoses to gain better access to my transmission, could that have cause the air bubble? Certainly. I would expect it. ---
**Author:** ![lucasm822](https://avatars.discourse-cdn.com/v4/letter/l/b5e925/32.png) [@lucasm822](https://community.cartalk.com/u/lucasm822)\ **Post date:** [May 7, 2009, 11:22am UTC](https://community.cartalk.com/t/car-temperature-guage-fluctuating/30150/7 "2009-05-07T11:22:45Z")
will check after school today. winding things down for the school year, so i should have time. I’ll let ya’ll know the results. ---
**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:** [May 7, 2009, 11:50am UTC](https://community.cartalk.com/t/car-temperature-guage-fluctuating/30150/8 "2009-05-07T11:50:12Z")
To get the air out of my 2000 Blazer’s cooling system I put it up on ramps to get the radiator as high as possible. I remove the radiator cap and start the engine with the heater running, as the engine warms up the trapped air should work its way out. I watch the radiator level and add coolant as needed. Ed B. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [May 7, 2009, 3:30pm UTC](https://community.cartalk.com/t/car-temperature-guage-fluctuating/30150/9 "2009-05-07T15:30:01Z")
The quickest way to remove trapped air in a cooling system is, get the engine up to operating temperature. With the engine idling, slightly loosen the clamp for the upper radiator hose. Take a flat bladed screwdriver and slip it between the radiator hose and the hose neck of the radiator. Allow the engine to idle until all the air is purged from the cooling system. Retighten the hose clamp. Tester