Engine Drivetrain 2nd Gen S Overheating - Need Advice

Discussion in 'Tuning and Performance' started by btwdriver, Jun 12, 2010.

  1. mini_racer

    mini_racer Well-Known Member

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    #21 mini_racer, Jun 19, 2010
    Last edited: Jun 19, 2010
    Ok, maybe splitting hairs here, and I definitely agree that 240 is too high; however, as Keith mentioned it is not technically 'overheating'. Sure, it is too hot and the issue must be remedied, but some of the classic symptoms of overheating are:
    - Coolant temp rises, and then keeps going, almost in a runaway thermal condition. Here though, it roughly plateaus at 240, and can be brought back down to more normal temps with more mild running.
    - Typically an overheating condition is accompanied by boiling over and spewing coolant everywhere.
    - Also, on a modern car I would expect some codes to be thrown

    So yeah, it is way too hot, but to me it is not technically 'overheating'.

    Back on the electro-mechanical thermostat, it does not seem to be executing the 2nd setting for spirited driving.
    - If it is not the heart shaped device itself, then could it be a control signal that actuates a valve to increase the flow?
    - Where is the sensor/temp probe? I am guessing it is #5 in the exploded view diagram and that is has already been replaced. Hmm...
    - How about the spirited driving signal? Is that determined by the throttle position sensor? I am not sure.
    - So, you added an inline coolant temp sending unit that feeds the gauge. Could something have changed there such that it is now limiting flow in that line?
    - Check all related electrical connections and connectors again. Is there a corroded wire/line somewhere?

    - Also what about the FMIC, are you getting proper air flow threw it and to the radiator? Did you install a larger FMIC recently that is limiting fresh air flow to the radiator? Neither is likely, but worth considering.

    Just throwing stuff out there, maybe something will click with one of the experts out there.
     
  2. btwdriver

    btwdriver New Member

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    When I say the temp reached 240 degrees, that is where I shut the car down and start driving "normally". If I were to continue to push the car I have no doubt the temp would run away until you definitely broke something. I have tested this by taking the temp all the way to 250 and it was showing signs of continuing to climb.

    Upon first entering the track the temp initially drops, indicating that the higher flow mode has kicked in. I have not added a new FMIC (I have had a larger one for more than a year now).

    When I had the thermostat out, I checked all the electrical connections and everything seemed ok.

    I keep going back to not having this problem until I had a broken downpipe that melted the valve cover. That episode must have overheated a portion of the head causing some very minor head gasket/head damage. Everything was fine until this happened and I have had issues since. I can't not think the two are related.
     
  3. Jason Montague

    Jason Montague New Member
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    #23 Jason Montague, Jun 20, 2010
    Last edited: Jun 20, 2010
    Engine Operating Temp

    :Thumbsup:btwdriver I'm very sorry that you are having this problem and I hope that it is solved very soon but, you and the other people have solved my problem with y'alls information. Like many of us I have a Scan Gauge II and I do monitor it while driving. Like 'YESIFIT' says,normal operating temp regardless of ambient temp is 220 degrees F. When I switch on 'Max Air' the temp drops 40 degrees to 180 or even 175.Well,y'all explaining about the '2 temp' thermostat now explains why that happens. I can be sitting at a long stop light at 220degrees. Turn on ' Max Air' (strangely regular a/c won't do it) and within moments ,the temp has plummeted 40-45 degrees to 175-180. Now I know why. Thanks Every One :Thumbsup: Jason :cornut: Mini Margi is 2008 R56 MCS JCW
     
  4. btwdriver

    btwdriver New Member

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    Jason you bring up a good point. I don't think I have ever used the max air setting on my car. That might be a good way of ensuring the thermostat/water pump is operating as designed. Ross can you conform this behavior some time with
    your car? I want to make sure the behavior is consistent across all cars before I try and use it as a diagnostic technique.
     
  5. Jason Montague

    Jason Montague New Member
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    Engine Operating Temp

    :Thumbsup:You are very welcome Sir. If you hadn't brought this up(2 temp thermostat),I might have never known why Margi runs cooler under load.:cornut: Jason
     
  6. mini_racer

    mini_racer Well-Known Member

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    #26 mini_racer, Jun 20, 2010
    Last edited: Jun 20, 2010
    OK, my understanding is that the Max AC cooling is effected by additional air flow across the radiator via the max electric fan speed, NOT additional coolant flow.

    So, this leads me to believe that the issue at hand is the 2nd stage of the electric radiator cooling fan, and not a coolant flow or possible head issue at all. Fan problems, or rather the resistor pack for the fan is a common 1st Gen issue, but I have not read much about a similar problem with the 2nd gens.
     
  7. btwdriver

    btwdriver New Member

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    I would not think that it matters how much the fan is running when you are running 60-100 mph on a track. I would think that sufficient air flow to cool the radiator.

    I did notice today that when I turn the AC on max the temp did not drop at all. This was done while driving mildly around town, from the base temp of 230. I also think that I heard a slight whining/whirling sound coming from the engine at idle. That is similar to issues other people have reported with their water pumps failing. Something about the friction plate, I have not had the water pump out yet so that is really all I understand about it at this point.

    I think perhaps a trip to the dealer to read any hidden codes as well as a water pump replacement is in my future.
     
  8. Nathan

    Nathan Founder

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    At this point I'd be suspect of everything including a clogged radiator.

    As an aside...to bad a certain club's board voted down the purchase of a sophisticated code reader for member use. (/me walks away whistling)
     
  9. mini_racer

    mini_racer Well-Known Member

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    On the 1st gen, the AC controls can make the radiator fan turn on max, not sure if it works that way on the 2nd gen though. And yeah, I sure would hope those speeds are enough to push all of the air through that is required.

    And if you are hearing what sounds like a strange water pump noise, then it is definitely something to check out.

    Good Luck at the dealer.
     
  10. Jason Montague

    Jason Montague New Member
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    Engine Operating Temp

    :Thumbsup:Good Luck btwdriver.I know how much that you love to drive. Gene,Steve,Marc,Bill and the boys at Mini of Dallas will have all set right in a jiffy and you'll be back on the track.:Thumbsup: Jason
     
  11. Jason Montague

    Jason Montague New Member
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    :Thumbsup:Thanks Nathan. You just told me that when I mentioned a 'certain club' in a post earlier today and typed in CENSORED Mini ;I did the gentlemanly thing. Yes?:Thumbsup: Jason
     
  12. YesIFit

    YesIFit New Member

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    Hey .. don't blame me, I voted FOR it!
     
  13. lotsie

    lotsie Club Coordinator

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    We just got a new Garmin OBD HD reader, bluetooths to the GPS. In gauges mode it displays all kinds of stuff, in real time, or very close, and when I turned on MAX A/C, the temp. dropped from 228 to 190 in less than 20 seconds. Driving on residential side streets, with many stops signs.

    Mark
     
  14. btwdriver

    btwdriver New Member

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    Thanks for the info everyone. My car definitely does NOT do this. I dropped it off to the dealer this morning to try and get them to replace the water pump. That is really the last thing on the cooling system that I have not already ruled out.
     
  15. mini_racer

    mini_racer Well-Known Member

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    So, how's the new water/coolant pump?

    Again, I know it is difficult to really test it unless you have ready access to a track.
     
  16. btwdriver

    btwdriver New Member

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    The water pump has been replaced with no improvement. I also had the dealer upgrade the ECU software version because the thermostat seemed to be acting a little funny.

    Currently the thermostat is acting normally, the temp drops when you turn on the max ac or rev the engine. It also drops initially when you pull onto the track. But that is where the good news ends, each lap on the track the temp climbs around 10 degrees until I stop pushing the car. Then the temp returns to normal.

    At this point I am convinced that there is a head/head gasket issue that only manifests itself under high RPM's or high boost pressure - probably the boost pressure. I have been talking with Werkin Mini about doing some head work when I have it pulled off. Which will be pretty soon.
     
  17. mini_racer

    mini_racer Well-Known Member

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    I would expect a leaking head gasket under high boost pressure to leak into the water jacket adding an air gas mix to the coolant and resulting in the coolant to overflow with all of the extra ~air in the system.

    So, a leaking head gasket is not an assignable cause that would intuitively fit the symptoms, at least not to me.

    Regardless, Werkin is a good ally to have in this battle.
     
  18. orangecrush

    orangecrush New Member

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    Sorry if this is an old thread. I didn't look at the dates. Anyway, I had the same problem when I was at the track last time at CMP.

    I have no gauges but the idiot light came on so I pitted, left it running to cool down.

    The reason I mention this is because the last time I went to the dealer, I was told my waterpump had an issue.

    He said he could tell because you could hear a hiss when I shut the car off.

    Not sure if u hear the same thing buy....


    Mark
     
  19. btwdriver

    btwdriver New Member

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    I replaced both the thermostat as well as the water pump, just to rule these both out.
     

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