Over heating GU 4500

[lloyro]

Hi, I'm Lloyro and have a '98 Patrol GUII, 4500.
I am having problems with the Radiator Fans 1 & 2 not operating causing overheating problems. Has anyone any suggestions as to what the problem could be.
Thanks. Lloyro.

[YNOT]

Not sure what you mean by "radiator fans 1 & 2"?
4.5 GU had an engine driven fan for cooling, if this fan is not operating the viscous hub is a likely cause. The electric fan is there to assist the air conditioner at low speed.
What condition is the rest of the cooling system in?

Tony

[lloyro]

Hi Tony, thanks for coming back. The two electric radiator fans in front of the radiator are designated as Rad1 and Rad2 on both the fuse panel and relay panel. I had presumed these were there to come on if the engine got too hot and to assist the engine fan cooling which is operating ok. The fuses and relays are ok - now if these are only there to assist the air conditioner at low speed (which is very logical) I obviously have a problem with the thermostat. The cooling system is in good condition having had a flush out and new Nissan coolant approx. 3 months ago. A complete set of new belts fitted 3 weeks ago.
I fitted a new thermostat approx. 18 months ago, and would have expected it to go a bit longer. Genuine parts used.
The vehicle has done 210,000Km and is in good condition. I fitted a vacuum gauge to monitor the engine and it shows the engine is in good condition.
Lloyro

[YNOT]

When you say the radiator was flushed out was it a professional clean where they take the tanks off and push a cleaning rod through the cores? If not you may have a partial internal blockage of the radiator.

Tony

[lloyro]

The radiator was drained and back flushed but not rodded and appeared to have a good flow. However, I will fit a new thermostat to see if this resolves the problem, if that fails then I will have the radiator cleaned by a radiator specialist.
Lloyro