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Overheating Problem

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Best Answer Captain Mainwaring , 07 August 2013 - 01:45 AM

Hey guys, just a quick one: I took he mini for a short drive yesterday and then I took the rad cap off and put a temp sensor in the top of the rad, the temp read 90 degrees and the gauge inside the car was just below he red line. my question is: what is the normal running temp?

 

 

You shouldn't have taken the cap off, though in this case it doesn't matter, the car wasn't boiling. You have however answered your own question and solved your own problem - a car isn't in the red at 90C :-)

 

anything between 82 and 92 degs is quite normal temp

in the cylinder head temp will be slightly higher, so i'd expect the gauge reading a bit higher, when temp outside gets above 30° minis tend to run quite hot, but if temp goes quickly above 95-98 degs while driving, then you have a problem somewhere

 

Well not really once you are above the stat opening temperature. 

The circ water temp will increase once the balancing point of the cooling system is reached - given a certain ambient temp with the engine under a certain operating condition, the circ cooling water temp will increase until their is sufficient differential in the circ water temp and the ambient air temp to effect a change in the heat balance and allow heat energy to flow from the cooling system to the surrounding air. Heat transfer is expressed as W/(mK) so a cooling system water/air will loose 1/(273+new ambient temp-original ambient temp) *100% efficiency for a given change - it won't suddenly get worse at 30C.

 

I don't  reckon an engine is excessively hot at 90C and the gauge certainly shouldn't be in the red - unfortunately these are hardly calibrated instrumentation and I think there may be a huge difference between calibration of gauge head units and PT100's (i'm guessing that they are 100's)

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#46 Captain Mainwaring

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Posted 14 August 2013 - 02:41 PM

Would you believe it I just came back to work from a two week break only to have two machines overheating. Turned out both had weak springs on the vacuum valves. Two new rad caps later and both were back out working.

 

 

Rad caps don't have vacuum breakers...LoL ........


Edited by Captain Mainwaring, 14 August 2013 - 02:42 PM.


#47 daenesh

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Posted 14 August 2013 - 04:33 PM

i was joking guys come on cheer up.. just trying to lighten the mood here since everyone is so tense :)



#48 Yoda

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Posted 14 August 2013 - 05:41 PM

 

Would you believe it I just came back to work from a two week break only to have two machines overheating. Turned out both had weak springs on the vacuum valves. Two new rad caps later and both were back out working.

 

 

Rad caps don't have vacuum breakers...LoL ........

 

Explain, because you are beginning to get tedious.



#49 jmmini

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Posted 14 August 2013 - 06:42 PM

This needs closing

#50 Yoda

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Posted 15 August 2013 - 03:51 AM

I agree. this thread needs closing before i get my first warning for strong language. 

 

Time for Yoda to retire i think. I will miss most of you guy's and its a shame it has to come to this as i used to enjoy popping in here.

 

Goodbye, have fun, and behave.



#51 Captain Mainwaring

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Posted 15 August 2013 - 04:03 AM

 

 

Would you believe it I just came back to work from a two week break only to have two machines overheating. Turned out both had weak springs on the vacuum valves. Two new rad caps later and both were back out working.

 

 

Rad caps don't have vacuum breakers...LoL ........

 

Explain, because you are beginning to get tedious.

 

 

 

I made a perfectly sensible postings throughout this thread and the court jester seems to enjoy following me around and telling me what a fool I am and how much more he knows about minis - 

No need to leave, I'll do the decent thing first.







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