Thermostat or temp sensor?

Discussion in 'Mazdaspeed 3 Troubleshooting' started by coquims3, Mar 4, 2017.

Watchers:
5 users.
  1. coquims3

    coquims3 Greenie Member

    Joined:
    Feb 10, 2016
    Posts:
    19
    Trophy Points:
    3
    Location:
    Port Richey Fl
    Ratings:
    +12 / -0
    I don't know how long I've been having this problem but just noticed that when hard acceleration my temp drops all the way to cold, then after like 3 minutes it goes back up to normal but when I drive it regularly and it will be fine. Also no CEL. I searched everywhere and couldn't fine anything related.
     
    coquims3, via a mobile device, Mar 4, 2017
    #1
  2. DaTFranchise_ms3

    DaTFranchise_ms3 Greenie Member

    Joined:
    Sep 17, 2016
    Posts:
    71
    Trophy Points:
    18
    Location:
    Gainesville Fl
    Ratings:
    +39 / -0

    The factory gauge isn't very accurate, I would suggest an obd2 Bluetooth adapter and torque app or an iOS equivalent to see exactly what your temp is doing.
     
    DaTFranchise_ms3, via an iPhone, Mar 4, 2017
    #2
  3. nekret

    nekret Gold Member

    Joined:
    Feb 23, 2016
    Posts:
    578
    Trophy Points:
    43
    Location:
    Vancouver, WA
    Ratings:
    +132 / -0
    Try driving it gently at highway cruising speeds. If it stays cold it's definitely the thermostat stuck open.

    Sent from my SM-G920V using Tapatalk
     
    nekret, via a mobile device, Mar 4, 2017
    #3
  4. coquims3

    coquims3 Greenie Member

    Joined:
    Feb 10, 2016
    Posts:
    19
    Trophy Points:
    3
    Location:
    Port Richey Fl
    Ratings:
    +12 / -0
    When I drive it like that is stays on normal temps. It's when I push the accelerator all they way it start to fall to cold. It's very weird.
     
    coquims3, via a mobile device, Mar 4, 2017
    #4
  5. PadreDave

    PadreDave The happy and free Christian Platinum Member

    Joined:
    Feb 23, 2017
    Posts:
    184
    Trophy Points:
    43
    Location:
    Mesa, Arizona
    Ratings:
    +160 / -2
    You guys have a temp gauge? What generation Speed are you driving. I have a 2010 and would love to have a temp and oil pressure gauge.


    Sent from my iPad using Tapatalk
     
    PadreDave, via a mobile device, Mar 4, 2017
    #5
  6. DaTFranchise_ms3

    DaTFranchise_ms3 Greenie Member

    Joined:
    Sep 17, 2016
    Posts:
    71
    Trophy Points:
    18
    Location:
    Gainesville Fl
    Ratings:
    +39 / -0
    Mine actually runs much cooler on the interstate at 80 85 mph 175-183 vs 190's around town and slower driving 45-60 mph and I know my thermostat is good.
     
    DaTFranchise_ms3, via an iPhone, Mar 4, 2017
    #6
  7. nekret

    nekret Gold Member

    Joined:
    Feb 23, 2016
    Posts:
    578
    Trophy Points:
    43
    Location:
    Vancouver, WA
    Ratings:
    +132 / -0
    Yep that's normal behavior, I think what's going on sounds very much like a funky temperature sensor or wiring issues. Another thought, how's your coolant levels? Air in the cooling system can wreak havoc on temp sensors.

    If a thermostat fails open, it takes forever to heat up and temps will usually fall below 140 degrees on Highway cruising. On the other hand if it fails closed it will overheat constantly.

    Sent from my SM-G920V using Tapatalk
     
    nekret, via a mobile device, Mar 4, 2017
    #7
  8. coquims3

    coquims3 Greenie Member

    Joined:
    Feb 10, 2016
    Posts:
    19
    Trophy Points:
    3
    Location:
    Port Richey Fl
    Ratings:
    +12 / -0
    Coolant Level is ok.
     
    coquims3, via a mobile device, Mar 4, 2017
    #8
  9. DaTFranchise_ms3

    DaTFranchise_ms3 Greenie Member

    Joined:
    Sep 17, 2016
    Posts:
    71
    Trophy Points:
    18
    Location:
    Gainesville Fl
    Ratings:
    +39 / -0
    Yea I think it's a wacky temp sensor myself. I doubt there's anything wrong with his cooling system or thermostat.
     
    DaTFranchise_ms3, via an iPhone, Mar 4, 2017
    #9
  10. nekret

    nekret Gold Member

    Joined:
    Feb 23, 2016
    Posts:
    578
    Trophy Points:
    43
    Location:
    Vancouver, WA
    Ratings:
    +132 / -0
    Agreed, there's really nothing out of the ordinary behavior wise that would indicate an overcooling condition. So all that's left is a wacky sensor and/or wiring.

    Sent from my SM-G920V using Tapatalk
     
    nekret, via a mobile device, Mar 4, 2017
    #10
  11. coquims3

    coquims3 Greenie Member

    Joined:
    Feb 10, 2016
    Posts:
    19
    Trophy Points:
    3
    Location:
    Port Richey Fl
    Ratings:
    +12 / -0
    Well guys, I went and clean the coolant sensor plug with QD electronic cleaner and the problem went away. Thank you for all the help!
     
    coquims3, via a mobile device, Mar 4, 2017
    #11
    • Like Like x 3
  12. Lex2007

    Lex2007 Greenie N00B Member

    Joined:
    Jun 20, 2017
    Posts:
    5
    Trophy Points:
    1
    Location:
    20782
    Ratings:
    +0 / -0
    I'm having this same issue.

    My 2007 with 130k miles on it just did the same thing for the first time. On the highway, cruising for 3 hours and all of a sudden the temp gauge goes down to the 3rd hash mark from the bottom, stays there a couple minutes and then goes back to normal temp. Does this twice in 20 minutes. Then it does this again a the next day after hours of highway driving but this time a get a CEL.

    The water pump and thermostat were changed 35k miles ago. Car heats up from cold normally.
     
  13. StreetSpeed6

    StreetSpeed6 Welder Silver Member

    Joined:
    Mar 1, 2018
    Posts:
    210
    Trophy Points:
    28
    Location:
    Bedford, Indiana
    Ratings:
    +56 / -0
    Was the code for insufficient coolant temp? If it seems to run normal and warms up fine then it is most likely the coolant temp sensor. It’s usually if the car doesn’t want to warm up all the way or shows cool engine temps on the highway that the thermostat is stuck open.
     
    StreetSpeed6, via an iPhone, Dec 29, 2018
    #13
Loading...

Share This Page

Users Viewing Thread (Users: 0, Guests: 0)