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2007 Z1000 overheating issue

Discussion in 'Maintenance and Servicing' started by Z1000 07, Oct 2, 2015.

  1. Guys can you help,

    I have an 07 z1000 that is overheating at the lights, when I increase revs the temp drops a little.
    I have REMOVED the thermostat to see if that was the issue and it didn't help.
    I today went to bleed ( burp ) the cooling system as was suggested to me which I thought it could be the issue, but to my surprise when I run the bike with the radiator cap off there was no circulation of the water, WHY? And actually started to overflow slowly.

    Need advice please as I'm on a budget.

    Cheers guys.


  2. try cut and paste
  3. Only while stationary? Thermos not working!
  4. Water pump may be buggered if there's no coolant flow, could also be a head gasket, were there any bubbles coming through when overflowing?
  5. Doubt that you would see much movement until the coolant was hot enough to open the thermostat and I doubt that you could run it long enough with the cap off to reach that temperature without coolant going everywhere. The level will rise as it heats up and the coolant expands. The radiator cap should be a pressure valve to allow the system to pressurize. If the cap is leaking the system will not reach operating pressure and that will let the coolant boil at a lower temperature dumping coolant at least until there is not enough coolant to reach the overflow.
    • Agree Agree x 1
  6. Have you made sure your cooling fan is cutting in when the bike gets up to temperature? My cooling fan failed and needed to be replaced.

    If cooling fan is not coming on when the engine gets hot, try to run power directly to the fan. If the fan then runs, the temperature switch may be buggered. If the fan does not work with direct power, then it needs to be replaced.
  7. #7 Z1000 07, Oct 2, 2015
    Last edited by a moderator: Oct 2, 2015
    It's all fine on long trips, sure head gasket is fine, just confused that I can't see water flow in the radiator?

    Fans working and changed sensor, just surprised I can't see water flowing in radiator?
  8. Most modern bikes run very hot before the thermo fan cuts in (usually around 100 - 105 Deg C) If the temp creeps up and the thermo fan cuts in, everything should be fine. If the temp keeps climbing once the fan cuts in, It may be the radiator needs a good flush.
    If the temp went down a bit when you increased the revs, the water pump is working well.

  9. #9 Z1000 07, Oct 2, 2015
    Last edited by a moderator: Oct 2, 2015

    Remember I took the thermostat out, that's why I'm surprised I cannot see water flow on the radiator,it's fine on long trips.

    That makes me feel better, shouldn't I see water flowing in radiator?..

    No bubbles, If it was water pump the temp wouldn't go down when I rev it,im just surprised I didn't see water flowing in radiator?
  10. The level has to be lower for you to see the water flowing. If you lower the level so you can see the radiator core, you will see it moving once the thermostat opens. (I hope you have put it back in)

  11. I now realise your right, went for a ride tonight it's still happening when in traffic, I am going to buy a radiator cap as it could be this, what you think?
  12. Is it actually overheating or just getting hotter than normal?

    A lot of bikes will run up to 105deg at the lights.

    You checked the fan?

  13. Sorry to be a pain but help me resolve this issue buddy please.

    So my z1000 temp keeps on rising at lights, I stop it when it reached 116 ( I'm confident the head gasket is fine ).
    The thermo fan is working, coming on at 100 degrees, I notice the temp doesn't drop when it comes on.
    I've changed sensor
    Radiator cap
    Flushed radiator, cooling system etc with correct stuff ( got a little bit of shit out but not much ).
    Took thermostat out in case it could be playing up.
    Looked at water pump, it looks new, bikes done 50k, 3rd owner.
    Note when tempreture rises at lights I put the revs up and the temp drops a little for a few seconds.
    Whilst riding the temperature stays reasonable and doesn't overheat.

    Is it the radiator you think?

    Cheers Lionel
  14. If it was the head gasket you would be chewing thru the coolant.
    it would be boiling over every time you ride hot or cold !

    Is the filler neck of the radiator bent?

    when I had my gsxr tuned one of the benefits was lowering my thermo fan to come on at 95' and turn off at 90'.... Instead of the stock 105'-100'.
  15. Can you take a good, close-up photo of the radiator? It could be a matter of bent fins or a dead bug infestation clogging it up.
  16. Do you actually lose coolant? Get someone to test your pressure cap. If you are not losing coolant, you haven't go much to be concerned about.

    Cooling system pressure caps are designed to release coolant if the engine overheats. This prevents damage to radiator, hoses due to excess pressure. No coolant loss means there is no actual overheating.

    Where do you get your temperature readings? Vehicle gauges are often surprisingly inaccurate. Put most of your faith in a tested or new pressure cap. I would be inclined to ignore the temperature numbers altogether, unless you've tested the sensor for accuracy.

    It is quite normal for, and a design feature of, modern vehicle cooling systems to operate coolant temperatures well in excess of the boiling point of water. This increases the efficiency of the cooling system by providing a larger temperature difference (between the air temp, and the radiator temp) at the radiator. The bigger this difference, the faster heat can be disposed of by the radiator. High indicated temperatures are not risky stuff, coolant loss is. Coolant loss indicates an inability of the cooling system to maintain the engine temperature within the range of the design spec.

    To put how close you are going to disaster (coolant loss) in perspective.

    50 % coolant mixture adds 8 degrees to the boiling point of your coolant.

    That 50% mixture, if contained in a 15 psi cooling system, will not boil until you reach 129 degrees Celcius - this would provide you with an indication of how much "headspace" you've got before your lose your coolant. There are tables which will show you what the boiling temperature is for different pressures and for different mixtures. Not all cooling systems operate at the same pressure.

    Do not be tempted to change the radiator pressure release cap to a higher value to gain more headspace, - this could damage your radiator (too much pressure) or result in a blown hose or seal.

    I realise this has not necessarily fixed your problem, but I hope has helped you understand it.
    • Informative Informative x 1
  17. a few bent fins will not have any effect on the cooling .
  18. Ill

    I will check it out.
  20. If it's not low coolant, fan not working properly, radiator cap, thermostat, headgasket, or externally clogged radiator then logic suggests it's lack of coolant flow. Which leads to only a couple of suspects; water pump or clog/blockage somewhere in the coolant circuit. Your symptom of only seeming to overheat at stationary idle fits with both of these. Removing the thermostat and not improving the situation fits also, as does your observing little to no coolant flow with the cap off.

    I would suggest a thorough flush of the whole system, maybe even using a chemical flush (others might chime in on the merits of this), and refill with fresh coolant. While doing this maybe even dismantle the waterpump for a looky at the impeller and the shaft.

    Good luck.

    Edit: Are you sure you're not sending us on a wild goose chase with a faulty temp gauge!
    Serious question. Other than what the gauge is telling you, what other evidence is there that it's actually overheating?