Monday, Nov 17, 2008 at 23:06
Fan hubs in Nissan are known to be "dodgey" from new - probably worth going to a fixed fan and do away with the clutch hub altogether.
Also if the vehicle doesn't already have one - consider adding an aftermarket OIL cooler out front.
A lot of engine temp can be shed via the oil system - not just the water pump - radiator method, In fact if there's insufficient oil volume in the sump - it can act like a heat sink and keep storing the heat the radiator cannot shed, because unlike water, the oil will keep getting hotter way past water boiling temp (220 f under pressure of 12 pounds/inch squared or - a little more if you have a 15 psi radiator cap) in effect defeating the water cooling system once it starts escalating up past that 220f mark.
The extra oil volume of the connecting pipes and after market oil cooler helps to increase sump capacity a couple or 3 liters as
well as allowing the oil to do some of the cooling that the water cannot do for whatever reason.
Next consider adding a special water wetting agent for radiator coolant - in effect a surfactant!
What can happen is certain frequencies of vibration within the engine when it fires depending on the ignition timing and combined with the speed of the water circulation combined with restrictions within the water jacket - can set up a "harmonics/low pressure" pockets within the blocks water cooling channels - that forms small air bubbles on the cooling fluid side surface of the cylinder bores, and keeps the coolant from contacting the iron and drawing away the heat as it should!
The surfactant / wetting agent helps to prevent the fluid from forming those bubbles be reducing the surface tension of the fluid.
Next - consider adding a poly
water tank somewhere inside the vehicle and connecting it to a 12 volt marine deckwash pump - and plumb a half inch reinforced compressed air line (hookah hose works
well) to the front of the vehicle and up in behind the grill.
Block the end of the hose in front of the oil air con and water radiators (and steering pump fluid radiator, and transmission oil cooler radiator if you have them) with a plug & stainless hose clamp and fit a couple common fine garden mister sprays before the plug spac3d equidistant about 1/3 in from the side of the radiator and closer to the top of the radiatir than bottom!
Switch the 12V marine pump via the dash
Install a tap (inside the cab next to the on off switch) so you can shut the sprayers off manually when not needed and stop the tank siphoning empty when not in use!
This way - when you notice the EGT's (exhaust gas temps) and normal engine temps gaugue temps increasing (add a Exhaust Gas temperature probe or pyrometer as it is called in the exhaust pipe below where it exits the manifold and joins the exhaust pipe if you don't already have one) - you can turn on the tap and switch the misters out front on via the pump switch from inside the cab while driving.
The water spraying thru the radiatiors cores will act like an old "
coolgardie safe" as it evaporates and draw a LOT more temp OUT of the radiators for the oil and water radiators (and air con and trans fluid etc) and everything will cool way down when under load while your driving.
You will see the engine temp gauge drop also the EGT's and if you have them Trans oil temps, and engine oil temps...they will ALL drop as you apply the water!
Also your air con will blow NOTICEABLY COLDER air for a while!
I only use the water boost pump switch etc when towing heavey loads at speed up hills in the heat 40+C days or into strong headwinds etc.
It works - simple as that and when not in use, the spare water is handy for other purposes. In an extreme stranding situation it might save your life. I have an additional snaplock connection plumbed to the rear bumper and a coil of garden hose with fire nozzel in behind the back
seat as an emergency fire fighter should I ever get a tyre fire - I can use the water to hose down a molten rubber tyre fire to a temp below reignition point (after I've knocked it down with the fire extinguisher until I get the water hose plugged in and switched on). I carry a total of 4 fire extinguishers between the two vehicles and boat.
It may not save your vehicle trailer or boat etc but possibly a fellow travellers if you happen on the scene in time.
Lots of ways to skin your hot Nissan cat - I wouldn't be expecting Nissan to come up with any answers soon tho.
Might as
well do it yourself!
Works for me!
Cheers!
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