1st Gen R53 Cooper S Most liked posts in thread: Overheating only on-track and all out

  1. BThayer23

    BThayer23 Well-Known Member

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    #5 BThayer23, Mar 26, 2013
    1. Compression test
    2. Leakdown test
    3. Change the oil and look at it
    4. Oil analysis

    I ran an oil analysis after a few track weekends and a blown supercharger last summer. I got really nervous when there was coolant in the oil, but it turned out to be nothing. You can get a compression tester for $30; you're qualified to use it if you can change the spark plugs.
     
  2. Gizmo

    Gizmo New Member

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    #6 Gizmo, Mar 26, 2013
    What BThayer23 said! Go to autozone or the like and pick up the compression tester adapter. It's a hose with a threaded end that screws into the spark plug thread and then a pressure gauge attaches to the end of it. I paid $25 for mine.

    Just some addition info from what I am dealing with my mini, even though the PTO gears in the SC failed and the water pump failed (I replaced it new at 17k mikes ago), I could still bleed coolant from both valves and my heater blew cold air. So you can't really tell say the water pump is running okay.

    Unless you can do the work yourself, I would suggest the leakdown test and also get your cooling system pressure tested.

    Self-diagnosing can lead to unneeded costly repairs, if you are unsure just bring it to a trusted mechanic.
     
  3. Jason Montague

    Jason Montague New Member
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    #2 Jason Montague, Mar 25, 2013
    :cornut: After all of the obvious(coolant level, thermostat housing crack, coolant over flow tank leak/crack, a hose leaking) check the water pump 'bearing inspection hole' for leaking coolant or a 'rust' mark indicating a failing water pump.:Thumbsup:

    Jason
     
  4. ZippyNH

    ZippyNH Well-Known Member

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    #3 ZippyNH, Mar 25, 2013
    My guess....if you have to keep bleeding it... air or more likely combustion gasses are getting into the cooling system......so sounds like a head-gasket may be going.
    Hope I am wrong....but if the system has been properly bleed to start...the air is coming from somewhere....
     
  5. mini_racer

    mini_racer Well-Known Member

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    #4 mini_racer, Mar 25, 2013
    Yes, unfortunately that is my theory as well. Head Gasket :^(

    Maybe it is rpm, but more accurately my limiting factor is likely boost. With the higher boost pressures the combustion gasses are somehow being pushed into a water jacket. Somehow, meaning....... I hope it is just a gasket.
     
  6. mini_racer

    mini_racer Well-Known Member

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    #7 mini_racer, Mar 26, 2013
    1. yep, next on my list, I have some baseline numbers from a while back to reference.
    2. yep, just picked-up one today
    3. Visually the oil has no coolant in it, or vice versa.

    Just last night I took the cap off the overflow tank after sitting for 24 hrs after 3hrs of street driving, and it had pressure in it.

    On the street the temp is parked at 194F, never a problem.
     
  7. BThayer23

    BThayer23 Well-Known Member

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    #8 BThayer23, Mar 27, 2013
    Good luck with the testing. I hope it's something small, like a t-stat housing leak.
     
  8. mini_racer

    mini_racer Well-Known Member

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    #9 mini_racer, Mar 27, 2013
    Thanks but given this.....'Just last night I took the cap off the overflow tank after sitting for 24 hrs after 3hrs of street driving, and it had pressure in it.'

    The system seems to be able to hold pressure under normal conditions. My theory is that only under the extreme conditions of high boost and rpm it is leaking combustion gases into the coolant, via a bad head gasket(hopefully).

    I just changed the T-stat ~3 months back and the housing was not leaking then, sure it could be now, but I do not have any evidence of that so far.
     
  9. ZippyNH

    ZippyNH Well-Known Member

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    #10 ZippyNH, Apr 1, 2013
    Yup....all of us have watched some threads turn into train-wrecks!!
     
  10. mini_racer

    mini_racer Well-Known Member

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    #11 mini_racer, Apr 1, 2013
    That bit of Good Advice never gets old.
     
  11. Gizmo

    Gizmo New Member

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    #12 Gizmo, Apr 1, 2013
    I got 'lucky' with my issues since the things I replaced I was planning on replacing anyways, so no money was wasted.
     
  12. SNEEEZY - Erika

    SNEEEZY - Erika M/A Wrenchin' Babe!
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    #13 SNEEEZY - Erika, Apr 1, 2013
    Definitely sounds like a bad head gasket.