Over heating problem

[Steviej]

Hi all. I have a 2011 navara frontier import to Australia with 145,000 miles on it. I had a mobile mechanic come over to give me a road worthy certificate and blew the coolant out of the radiator with out my knowing( i wasn't there but my oldest boy watched him open the radiator cap and blow coolant everywhere when starting it). Not knowing this i drove it afterwards and had the temp gauge rise to below cooking point but not in the red. Since that time i have replaced the thermostat, entire coolant flush and oil change with filter. The temp gauge sits on the usual temp(just below the half way mark) until i do 110 kmh which is when the temp slowly moves up but once i drop back down to 80kmh it cools back down to normal temp. Ive bled the coolant system by the old way of a funnel in the radiator with the coolant level higher than any part of the engine but after 40 mins of running im still getting air bubbles. Engine runs happy and no smoke of any sort from the exhaust. Air con works flat stick but heater doesn't. Its a d40 frontier spain produced model. Help me out guys

 

[Czechmate]

My 07 spanish d40 STX has a coolant drain bolt in the side of the engine block

If you look straight in at 90 degrees above the front left wheel its in there, mine is coloured green on the bolt head

You need to get this out to drain the block properly

Then theres a coolant refill procedure written in the workshop manual for your d40

Be bloody careful pulling the drain bolt out

Mine was stuck in so tight i rounded the head off and now its in there forever

I just have to replace as much coolant as i can possibly get out at the end of every summer

So no proper flush for me it sucks

 

[Steviej]

Is it the bolt with a metal pipe connected to at about a 17ml size head or is it the bolt below the thermostat housing of about a 15ml size

 

[Infernal]

Radiator is blocked internally, when it's hot feel for cold spots on the radiator.

 

[Steviej]

But when i take the bottom hose off it drains completely and then fills back up once hose reconnected.

 

[Steviej]

Obviously by filling it myself that is

 

[Infernal]

Draining and re filling won't tell you if you have an internal blockage in the tube.

Go for cold spots and report back.

 

[Steviej]

All of my radiator is hot to touch at running temp but i can leave my hand on the centre of it and its luke warm

 

[jonney]

the reason why many radiators block up these days is due to old coolant in the radiator that gells up after time , this is why it is important to flush / drain and replace coolants when due. to clean out the gell build up it must be done professionally or a new radiator is needed. don,t buy a genuine nissan radiator unless you have plenty in the kitty.

 

[Infernal]

You have an internal blockage in the centre, the viscous fan hub relies on heat coming off the radiator to lock up, because the fan hub is in the centre and the temperature in the centre is Luke warm, there is no heat getting to the fan to cause it to lock up, causing the overheating, I suspect you are also able to rotate the fan at operating temperature which you shouldn't be able to do.

 

[Steviej]

Infernal your a legend. Appreciate all the info mate.
I'm getting a new radiator now and thanks for the expense info jonney. Cheers boys, life savers.