Front or side intercoolers?

Discussion in 'Technical' started by 93 Nissan 300zx owner, Dec 14, 2017.

  1. Fists

    Fists Well-Known Member

    How are you reading temperature, stock gauge, ECU read out or aftermarket? What temps is the engine actually getting to?
  2. tassuperkart

    tassuperkart Its a lie I tell you!

    This is true but ONLY when actually making all that extra horsepower. On a road car its limited to a few little squirts here and there which hardly extend a cooling system.

    One question to the O.P about the FMIC, is it mounted vertically and parallel with the radiator or stuck in there at some funky angle?
  3. tassuperkart

    tassuperkart Its a lie I tell you!

    He said it was seeing 100c temps within 10-15 minutes.
  4. Shane001

    Shane001 Well-Known Member

    It'll either be the fan clutch or air in the system. As per Dazza's post, you need to idle the engine up to normal operating temp with an inverted coke bottle sealed in the top of the radiator, topping up as necessary (only to the top of the rad neck) then once at full temp run it at 3000rpm for a minute or so, let it idle, run at 3000rpm, repeat a couple of times, continually topping up as necessary. By now the coolant will have expanded and will be half way up the coke bottle, hopefully no more bubbles, now shut it down and wait for the coolant to cool and 'shrink' back down, remove the coke bottle and all done.
  5. Fists

    Fists Well-Known Member

    So he did, right there in the first post. Even without a fan I would think that's excessive. OP, have you checked the temp of the lower radiator hose while the engine is hot? Sounds like either still air in the system or the thermostat or water pump isn't working.
    DazzaZ32 likes this.
  6. DazzaZ32

    DazzaZ32 Active Member

    Yep good call as the the thermo probably wasn't tested before installation(Stuck in hot water to see if opens)
    That with air in system hot car.
  7. Yeah thx guys I've checked thermostat and it's working but I'll have a check on the bottom hose to make sure there's no air. And yes FMIC is vertical to radiator. I'm using a stock gauge and I've checked ECU which seems fine.
  8. East Coast Z

    East Coast Z Well-Known Member

    I've checked thermostat and it's working.
    How did you check the thermostat?

    I'll have a check on the bottom hose to make sure there's no air.
    How do you propose you are going to do this?
    Air won't be trapped in the bottom hose.

    I'm using a stock gauge.
    The Z32 temperature gauge is not marked in temperature increments.
    How do you know it's reading 100 on the stock gauge?
  9. tassuperkart

    tassuperkart Its a lie I tell you!

    Yes this.

    "Checked" the thermostat.
    You said everything was new in the cooling system. I test even brand new thermostats in hot water before I use them. Overkill? Yes, but I KNOW the thermostat opens and opens fully, THEN closes again.

    How can you say your temp gets over 100deg.C with the stock guage. It doesnt show anything more that there is heat in the water.
  10. Thx heaps guys I'm going to be sorting out the fan and clutch this week cause I know that's the problem now. Thx again
  11. Fists

    Fists Well-Known Member

    As the others have said, the stock gauge is about as useful for checking temperature as sitting an egg on your bonnet. The stock gauge has three positions, and has a hard cut-off where it switches from "everything is absolutely dandy" to "shits on fire!", the needle just moves really slowly to trick us into thinking it actually reads temperature.

    So considering that, it's quite possible that the difference in water temp between the days you think it's fine and when it's overheating could actually only be a couple of degrees. The ECU has a separate sensor and reads the actual temperature, so long as the sensor is working properly, once you've done the fan and stuff refer to the ECU with some sort of scan software or install and aftermarket gauge to see what it's doing. With summer weather and the AC on it's perfectly fine for your car to run at 90C all day so long as it's stable, and that's why the stock gauge sucks, you have no idea if the temp has just nudged the upper bracket or is skyrocketing.
  12. tassuperkart

    tassuperkart Its a lie I tell you!

    The viscous fan clutch is regularly the culprit
    Its imperative on a Zed that the fan shrouds are complete and fitted as well. If the shrouds are not fitted, you might as well stand in front of the car and blow air out of you mouth into radiator for all the good the fan does.

    History has shown that the vast majority of those that have trouble with overheating have made major changes to the cooling system. Ie funky looking aftermarket radiators, electric fans in place of the stock fan, shrouds removed etc.

    Those of us with totally stock, maintained and working systems dont have any overheating issues. Nothing works as well as the stock cooling system. Its as simple as that.
  13. Central QLD Z

    Central QLD Z Member

    I reckon with the right improvements the stock system can be made better.

    I have a brand new OEM thermi, fan/clutch and full shroud but I felt great about getting the stock plastic internal rad out in favour of the Z1 Howe rad.

    Speaking of the stock rad - were they really plastic internals ??? Wasn't sure my mech was serious or perhaps I'd misheard. But anyway, he reckons the Howe is bloody Uber tier compared to the 24yo stocky - and rightfully so given the age I suppose.
  14. geron

    geron National Petroleum Equipm

    If you are using the OEM radiator, after nearly 25 yrs, ditch it and just get an Aluminium one from ebay.
    It doesn't have to be the thickest radiator, just a simple Aluminium unit nice and thin still, they are designed a little thicker than OEM and thus greater volume of coolant. The very thick radiators are a PITA to fit/remove and also to be able to fit the fan shroud.

    If you are using an OEM Fan clutch, after nearly 25yrs of faithful operation, time to ditch it for a new OEM unit. Nothing else but NISSAN. Aftermarket Fan clutches are NOISY. The Nissan OEM is nice and quiet and it works a treat.

    If the fan blades have been worn on the outside due to rubbing on the fan shroud for whatever reason, time for a NISSAN OEM replacement. They are specifically designed for the Z. Yes you can fit a pathfinder fan and whatever for 50c but just get the one that is for the Z32.

    Thermostat, don't use aftermarket. Buy genuine NISSAN Z32. Some cheap aftermarket units have a smaller opening (Inner diameter) by 3mm compared to OEM unit. OEM opens at 76.5 °C. Not 78 not 68.
  15. geron

    geron National Petroleum Equipm

    Also, since your car hits 100° after 10-15 minutes of operation, it sounds like a thermostat issue.
    The OEM truck fan is such a crude beast it moves a lot of air. I can't see your engine hitting 100°C after 15 minutes only unless if the thermostat is faulty. After that, if the fan clutch and fan itself are totally destroyed then I guess overheating will occur.
    However, to ensure the cooling system is up to the task, and to eliminate all uncertainties and have confidence, it's a good idea to replace 25+yo stuff if your having cooling problems.
  16. brisz

    brisz Well-Known Member

    Engine oil level ?, check on dead flat slab, five minutes after stopping. Make sure dipstick is fully seated. look for high tide mark on the wire.

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