DIY Car Repairs - Overheating nissan wingroad

So our nissan wingroad has been overheating quite often recently, as long as we keep moving it seems to be fine.

I investigated and found that water was not flowing through the radiator (hot pipe on top cold pipe on bottom and no hot air comes out on full hot inside) so straight away figured the thermostat so changed that. That made no difference so I figured water pump so me and a mate changed that, while it was drained of coolant we blew water through the radiator and engine block to ensure nothing was blocked. Sure enough it was still doing it, so I removed the thermostat and it appeared to work fine (of course assumed dud new thermostat). We drove it into town last night and sure enough it started overheating (still no thermostat fitted), when my wife went to pick it up today it went fine (normal temp hot air comes out) but then she took a trip to the supermarket a bit later on again again it overheated no hot air etc. So it is doing my head in, if you keep moving then it doesn't get over 3/4 on the temp gauge but it can't be good for it to going up and down in temp. The temperature also seems to swing very fast like it will drop from 3/4 to under a half in a matter of seconds which seems a bit fast to me!

So this is really doing my head in there isn't much to the system and it shouldn't be that hard to figure it out!

When I have refilled the coolant I have removed the plug above the thermostat and filled until coolant comes out there refitted the plug and continued to fill.But I am thinking there maybe an airlock or something stopping the flow through the engine!

Thanks for any help or suggestions anyone can offer.

Get your radiator rodded (or what ever its called)

And have your checked the pump!

Fan(s) not working! The system relies on the fan(s) when the car is not moving to keep a draught through the radiator.

Hi. When you have filled it with coolant run the car with the cap off the radiator.
The coolant will run over the top of the radiator but keep putting coolant in when the water level drops.
Do this till the fan comes on, when put the radiator cap back on and turn the car off .
And then check the water level the next day ORwhen the engine has cooled down and add waterif requied to the radiator.
I hope this helps Steve

My thoughts would be air locks as well as the above replys.

Pump has been changed, fans work but there is no flow through the radiator so fans just blow on a cold radiator and don't do anything.

Looks like it might be an air lock so will work on that tomorrow.Someone else said pull off one of the highest heater hoses and fill it until coolant comes out there and then run it topping up etc.

Check the hoses insides.I struck a hose once that had a flap of lining detach, and it blocked the water flow periodically.

That's a good idea might pull the main radiator hoses off.Getting a little bit sick of draining and refilling this bloody radiator!

I want to know is the the above problem resolve ready?