1st Gen R53 Cooper S Most liked posts in thread: Temp gauge reads lower after coolant change?

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  1. MCS02

    MCS02 Moderator
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    #8 MCS02, Jul 6, 2015
    on my 02 R53 I just put the heater on full hot and take the bleed screw all the way out. Crank the car and let it ideal. Then I pour coolant in till it is at the top of the tank. It takes a little bit for it to go down, then I add more coolant till its at the top. after a couple of times it starts coming out the lead screw. I let it come out of the bleed screw till no air is coming out. then put the bleed screw back on. If the expansion is to full I use a suction to take the excess out. Clean up any spoiled antifreeze. It only takes a little to kill a animal, and its a slow painful death.
     
  2. MCS02

    MCS02 Moderator
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    #10 MCS02, Jul 6, 2015
    ^^^^^^^^YES ^^^^^^^^^ PLEASE^^^^^^^^

    Only the link is to the one for the cooper. If you have an S get the one for the S. It is worth the money. Look around sometimes it can be found at a descent price.
     
  3. BlimeyCabrio

    BlimeyCabrio Oscar Goldman of MINIs
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    #11 BlimeyCabrio, Jul 7, 2015
    There's a second bleed screw in the metal coolant tube just forward of the thermostat housing. Do NOT take it all the way out, you only need to crack it and air / coolant should come out. Just crack that one long enough to get a trickle of coolant, then close it.
     
  4. rivercityRN

    rivercityRN New Member

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    #19 rivercityRN, Jul 24, 2015
    CEL with code P0128 confirmed it: Coolant Thermostat. Changed thermostat, gasket and housing and all is back to normal. Thanks for the assistance guys:smile5:
     
  5. rivercityRN

    rivercityRN New Member

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    #23 rivercityRN, Jul 26, 2015
    Tried it both ways Firebro and you're right...works best when running.
     
  6. Canusrufis

    Canusrufis RMW Powered R53
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    #2 Canusrufis, Jul 5, 2015
    when was the thermostat last replaced? could be stuck open not allowing the coolant to warm up. How long did you let it run? -- mile or so may not be enough time to enamor up.
     
  7. Canusrufis

    Canusrufis RMW Powered R53
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    #9 Canusrufis, Jul 6, 2015
  8. BlimeyCabrio

    BlimeyCabrio Oscar Goldman of MINIs
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    #14 BlimeyCabrio, Jul 11, 2015
    Sounds like thermostat is stuck open. I don't think it will hurt anything this time of year. In the winter, it will take the car too long to get up to operating temperature, and might keep your heat from being "hot".

    Yes, replace thermostat, or check it for debris that's holding it open.
     
  9. BlimeyCabrio

    BlimeyCabrio Oscar Goldman of MINIs
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    #15 BlimeyCabrio, Jul 11, 2015
    Btw... You can test the thermostat. Should be closed when cool. When placed into boiling water on the stove, it should open once it heats up.
     
  10. ZippyNH

    ZippyNH Well-Known Member

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    #16 ZippyNH, Jul 11, 2015
    Having a car run too cool will result is slightly lower mpg...OK for the short term, longer term issues of not getting the oil hot enough to boil off moisture would be a concern longer term..
    Guessing your thermostat got stuck...maybe some gunk got disturbed in the fluid change, and jammed it...
    Kinda lucky it got stuck in cool....
    Most typically get stuck in the hot position unless they are one of the premium brands made to stick cold(not available on the MINI)....
    I would get it taken care of sooner than later...but driving it locally while you wait for an appointment should be OK.
     
  11. Nathan

    Nathan Founder

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    #17 Nathan, Jul 11, 2015
  12. Firebro17

    Firebro17 Dazed, but not Confused
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    #22 Firebro17, Jul 26, 2015
    Great to see that you changed the thermostat and your problem was corrected. Also, did you run the engine to bleed the air? I've never known bleeding to be all that effective without it running.
     
  13. rivercityRN

    rivercityRN New Member

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    #3 rivercityRN, Jul 5, 2015
    I let it idle for 15 minutes or so and it reached the normal temp...midway on the gauge. After driving it for a few miles, the temp slowly drops to the 1/4 mark and remains there until the next stop or idle period, at which time it goes back to halfway. I put about 30 miles on it today and had no issues aside from the low reading on the temp gauge:confused5:
     
  14. Canusrufis

    Canusrufis RMW Powered R53
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    #4 Canusrufis, Jul 5, 2015
    Yea thats plenty of time for engine temp to reach operating. I'd check thermostat as a failed sensor is less likely (I could be wrong). Or the cooling fan is running constantly causing over cooling.

    If it sis the thermo I'd replace the housing too.
     
  15. rivercityRN

    rivercityRN New Member

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    #5 rivercityRN, Jul 5, 2015
    Not sure if it matters, but the car did overheat according to the temp gauge when the T-connector broke?
     
  16. Canusrufis

    Canusrufis RMW Powered R53
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    #6 Canusrufis, Jul 5, 2015
    Probably low fluid condition. Or coincidental. I can't image replacing a leaking T-connector would keep the engine from heating to operating temp. I know you said you burped the system but could have air pocket at the thermostat keeping open. I'm just guessing here. Also I'd turn the heater highest temp, full blast, windows down then try burping system. I sometimes park on a neighbors steep drive to get the radiator higher than everything else.

    Maybe someone else will chime in.
     
  17. rivercityRN

    rivercityRN New Member

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    #7 rivercityRN, Jul 6, 2015
    Could anyone outline the correct procedure for bleeding or burping the coolant system? Or post a link to site that has the info? There seems to be a discrepancy between my Chilton book and a few YouTube videos as to whether the engine should be running, the expansion tank cap is on and the correct amount of time to spend with each bleed screw open.
     
  18. Canusrufis

    Canusrufis RMW Powered R53
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    #12 Canusrufis, Jul 7, 2015
    It covers r50,53,52:wink:
     
  19. rivercityRN

    rivercityRN New Member

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    #13 rivercityRN, Jul 11, 2015
    I drove the car over to my in-law's home and bled/burped the system for a third time on their steep driveway. The moment I turned either bleed screw I got an immediate spray of coolant. So if there is no air in the system, am I left with a faulty thermostat? Aside from the temp gauge dropping to the 25% mark at operating speed then resuming midway at idle, there are no apparent issues. What are the potential effects of continuing to drive without changing the thermostat?
     
  20. rivercityRN

    rivercityRN New Member

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    #18 rivercityRN, Jul 11, 2015
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