Possible Overheating Problem

Discussion in 'Technical' started by RedZed32, Sep 11, 2014.

  1. RedZed32

    RedZed32 New Member

    Ran into my first problem with the Zed since buying it :(
    Whilst cruising along a main road the ECUtalk starting flashing that my temp had hit 100 degrees, quickly turned the car off and pulled over, from what we could see (myself and bRACKET) there was no leaks. Topped up the rad with water and drove home, without the temp rising this time
    Drove the car the next day and all was fine, temp sat at 80-82 degrees, but just now as I was driving home the temp jumped to 90, turned the car off and inspected it again, and yet again nothing. I continued driving home and the entire way the temp was fluctuating between 73-88, arrived home and yet again topped up the rad with water (drank over 1.5 litres)

    So my question, has this happened to anyone else? Was it an electrical problem (CTS) or was it something mechanical?

    From what I can see there are still no leaks, and the car is parked on a pretty large slope and there is nothing leaking from below

    Any help is appreciated :confused:
  2. JEDI-77

    JEDI-77 Jedi Master

    Some things to check...

    I'm assuming that the driving wasnt stop start traffic??

    Without any visible leaks, I would first be checking the radiator. It might need to be removed, rodded and reinstalled. Also check the condition of the viscous fan. Does it spin freely??

    After that, I'd be looking at the radiator cap, maybe just replace it with a new one to be safe.

    If there are no leaks, you shouldnt have to be topping up the radiator. So the water is going some where. Either being forced back into the reservoir bottle, leaking elsewhere or worse case scenario a leaky head gasket.

  3. RedZed32

    RedZed32 New Member

    Nope just driving along the main road tonight, no traffic

    I just checked the fan, spins freely
    Once I get home tomorrow from work I'll have a proper look for leaks, if nothing comes up I'll look into rodding it.

    Really hoping the head gasket isn't the problem, was told what will be involved in fixing it and I do not have the funds for that :(

    QLDZDR ID=David

    Check the radiator fluid for engine oil, Flush the radiator, check the thermostat, refill with coolant. So you have done all that?

    You mentioned Bracket? He could probably tell you if your clutch fan is spinning too freely.

    Do you have the aircon running when this problem occurs?

    If you have access to a drill press and tap and die, empty and refill your viscous clutch fan, its cheap to do and probably due.

    Check that your axillary fan is working as it is supposed to. Check the electrical plug contacts.

  5. brisz

    brisz Well-Known Member

    You are losing water for ffs.

    Doesn't that tell you something ?

    Yes the water is coming out somewhere.

    The temps you mentioned are considered reasonably normal as far as not causing damage to the head gasket, its the water lose that is causing the temps, not the temps causing the water lose imo.

    Although the water at temp creating pressure is what is pushing water out a small hole and as water level drops efficiency is lost and water temps rise.

    Either a small leak (soon to become a big one) or a radiator cap problem.

    Easy diagnostic, get a cooling system pressure test (inc. rad cap) as per page LC-9 of manual.

    Likely places to get a small leak in an NA:

    1) Heater core, coolant smell in car if you have coolant.
    2) 2 small bypass hoses on front of engine behind water pipes, look for weep stains.
    3) Radiator core near end tanks, look for weep stains.
    4) Water pump shaft.
    5) Welch plugs
    EDIT 6) *Under plenum water hoses, if bypass has not been done.

    Take it back to the douche you bought it off and demand warranty. :p

    Last edited: Sep 11, 2014

    TWIN TERROR Well-Known Member

    If you have a Nissan radiator with the plastic neck I would first check that the cap is tight on the tabs as they have a habit of wearing on the neck where the tabs turn against to tighten the cap. You can squeeze the cap tabs tight with multi grips a little bit at a time and test. It can be hard to see it leak as you have to look at the exact time it spurts out. If you stop and let it idle then hop out and look under the radiator and wait 5 mins you might see it leak.
  7. RedZed32

    RedZed32 New Member

    Ah thank you, will be checking over those spots when I get a chance

    Massive help :)

    I'm definitely in no position to be making demands :p
  8. brisz

    brisz Well-Known Member

    Excellent advice.
  9. brisz

    brisz Well-Known Member

    Is it an auto ?, on highway do you have auto "overdrive" on or off ?
  10. mikemd

    mikemd New Member

    Remove hose and check join of top radiator outlet (plastic) and radiator tank (metal); they tend to split at joins (especially at base of outlet pipe) and the hose clamp and hose can tend to disguise a leak, even if intermittent. Quite common and causes the exact symptoms you mention.
  11. RedZed32

    RedZed32 New Member

    Ah sorry Dave!
    I missed your post, it's not a standard radiator, was upgraded by the previous owner

    Brisz, it's a manual :)

    Mike, thanks for that, will inspect tomorrow
  12. rob260

    rob260 Administrator Staff Member

    Pressure test it.

    Then fix the leak.
  13. East Coast Z

    East Coast Z Well-Known Member

    What about......

    ......the overflow bottle?
    You mentioned you topped up the radiator with water, did you check the level of coolant in the "overflow bottle"?
    Notice I used the word coolant, that is what you should have in your cooling system, 50% distilled water & 50% ethylene glycol as known as antifreeze.
    By adding water to the radiator, you are diluting the coolant.
    The temperatures indicated are nothing to be alarmed about, the coolant loss is an issue that needs to be rectified.
    As John has suggested the place to start is with the pressure tests of the system & cap.
    The "overflow bottle" & hose connecting it to the radiator are also known as the "coolant recovery system", so make sure it is clean & working effectively.
  14. michaelZ

    michaelZ New Member

    Losing water is not the only cause of overheating.

    The more important issue is the loss of pressure due to a leak. Any leak results in two things. Loss of coolant and a reduction in the cooling system pressure. The pressure (14psi) increases the boiling point of the water to above 100C. This stops the water changing to steam at 100C which will decrease the efficiency of the cooling system. The cooling system including hoses are designed to only take 14psi of pressure. Losing water means a leak which also means loss of pressure hence oveheating if the head gasket is not damaged.

    You should never lose coolant in a properly functioning cooling system and engine.

  15. QLDZDR

    QLDZDR ID=David

    YES, you do have to discover where the water is leaking and where it is going.
    If you put on a protective glove and remove the 710 cap do you get a burst of steam?
    You should not have water in your engine oil, if it leaks in then steam might be detected.
  16. michaelZ

    michaelZ New Member

    Borrow or make a cooling system pressure tester.

    I ended up making a pressure tester myself. Got a lot of use out of it in the years after I made it.

    This issue is that without this tester the only way to pressurise the cooling system is to get the engine up to operating temp. Any coolant leak that drops on the hot engine will immediately evaporate and dry up leaving no trace to follow to the source of the leak. Pressurising the system when cold will leave a trail that can be traced.

    A case in point. I could not find a leak in one on my vehicles by running the engine and checking so I suspected a freeze plug behind the flywheel. (not a ZED). After checking this I borrowed a tester and discovered a leaking hose at the clamp. 1/4 turn of the clamp and it was fixed.

    Last edited: Sep 12, 2014
  17. RedZed32

    RedZed32 New Member

    Thank you all for the advice, finally got a chance to inspect the Zed this morning.

    I went about ticking off checking what Brisz listed, and the very first thing he listed seemed to be the most likely (Heater core), I have been smelling something weird in the car occasionally, never suspected it to be anything wrong. Turned up the passenger side carpets and revealed the source of the smell.

    As for the cooling system pressure tester, it seems like a worthwhile investment, just in case the heater core isn't the only problem.

    Again, thank you all for the help.
  18. CHILI

    CHILI Indestructable Target

    Just in case you have not already done so, DO THE HEATER CORE BYPASS(as listed in the forum "How To's").
    It just requires a few minutes and a short length of Heater Hose. It will get you back on the road until you can afford to do the Heater Core replacement.:zlove::br:
  19. RedZed32

    RedZed32 New Member

    That's the plan Chili! Got some hose being sent down by Anti, saved me big time :p
  20. rob260

    rob260 Administrator Staff Member

    At $8/metre you could probably have bought the hose from Repco (or similar) for less than the cost of postage but glad you have it sorted :)

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