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Gggrr more overheating woes.

DavidGB Jul 19, 2019

  1. DavidGB

    DavidGB Supporting Member

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    I have just got back from a 500 mile round trip on my 900, it ran perfectly, good power etc, but it spewed rusty coolant out of the exansion tank under the seat from the pipe beside the cap, the expansion tank is now below the 'low' level mark. Also when i stopped i could hear it perculating like a coffee machine. I checked the coolant level before i set off at the filler cap and it was full. The fan was kicking in but not on continuously, which i thought it would be if it was overheating catastrophically.
    I was going to start investigating but wondered if there was anything anyone knew of that could cause these symptoms. Theres no water in the oil and no visible water leaks.
     
  2. R. J.

    R. J. Supporting Member

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    :hello: If the coolant is rusty I'd flush the coolant system 3 times or until no rust comes out. Drain it at both the water pipe drain and at the water pump. You might need a new thermo-stat and or a new radiator cap.
     
    Last edited: Jul 19, 2019
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  3. 87kawzl

    87kawzl Supporting Member

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    Like RJ said, cap, thermostat and coolant change. Make sure you burp the system like the manual shows.
     
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  4. R. J.

    R. J. Supporting Member

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    :hello: You can down load the manuls for your ZL 6 in the down load section here on the forum.
     
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  5. DavidGB

    DavidGB Supporting Member

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    Thanks guys, i'll drain it all down swap out the stat and cap, i've bought some radiator flush aswell, about time i spent some money on the old girl.
     
  6. Harriminator

    Harriminator Senior Member

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  7. Trojan441

    Trojan441 Well-Known Member

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    While cooling is on the agenda, does anyone still supply hoses as a kit or water-pump parts?
     
  8. R. J.

    R. J. Supporting Member

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  9. DavidGB

    DavidGB Supporting Member

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    ok so while i wait for my new rad cap i thought i'd flush the system etc. when i removed the cap the coolant was about 1/2 pint low (after it's 500 mile trip where it spewed out rusty coolant) i topped it up and started the bike letting it run for about 15mins. After about 10mins the fan was cutting in and out every 40 secs (approx) i took some temp readimgs with my ir gun, do these seem normal to you guys? it was still doing that perculating thing at the coolant tank when i turned it off.
    top of rad 160f
    btm of rad 250f
    therm housing 200f
    water pump 150f
     
  10. Harriminator

    Harriminator Senior Member

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    I try to unterstand your values and am a lil bit confused but first of all: perculating means level is sinking, right? (percolating?). Normally the hot water runs from top to bottom in the rad and cools down - have you mixed up the values? 250°F = 121°C ...way too high! When engine is running the 110°C-switch is active (if oilpan120°C-switch is not working to change to 97°C rad switch) to start fan so how can it get 121°C? When water is lost in coolant tank it flows back into system so I think your cap is really done. I suggest to make a pressure test of the system @ some service station to see if it isn't 'worst case'...
     
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  11. DavidGB

    DavidGB Supporting Member

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    Yeah i couldn't understand why the bottom of the radiator was hotter than the top? i am worried that when i rebuilt the water pump last year, maybe i put the bladed rotor on the wrong way? i will have to check a spare i have to see if thats even possible. I am hoping the new cap will cure all this.
     
  12. R. J.

    R. J. Supporting Member

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    :hello: Check the fan switch located on the rear center bottom of the radiator. It has a black wire lead. My ZL 10s fan was going on and off every 10 seconds or so. Come to find out the wire lead was being held on by one wire strand. The water pumps finned propeller can go on only one way.
     
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  13. Harriminator

    Harriminator Senior Member

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    What came in my mind: when measuring @ the bottom of the rad there are the exhaust pipes which are very hot so beside the emission of the rad you have reflexions & transmissions which may distort the value on ir gun display; looking @ the pump temp 150°F the rad temp can't really be such high and fall @ this short way to the pump about 100°F. :nono:
     
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  14. DavidGB

    DavidGB Supporting Member

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    took her out for a blast with the new cap on and it seems to have fixed it, i overlooked the obvious, thanks for your help guys!
     
  15. 87kawzl

    87kawzl Supporting Member

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    Good to hear a cap for less than $10 and a jug of coolant has you back on the road again.
     
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  16. R. J.

    R. J. Supporting Member

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    :hello: What kind/brand of coolant did you use. Most Automotive antifreeze contains additives that will destory the water pumps ceramic seal.
     
  17. R. J.

    R. J. Supporting Member

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    Last edited: Jul 31, 2019
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  18. DavidGB

    DavidGB Supporting Member

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    i used one that had something to do with 'oat' written on it.
     
  19. Harriminator

    Harriminator Senior Member

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    Deep thr'oat'?:whistling::D
     
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  20. 87kawzl

    87kawzl Supporting Member

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    Very corrosive!!! Sicko. Was her name Sandy?
     

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