Weird Overheating Issue (2.8 V6)

[down_n_dapper]

So Having issues with my car recently as the temperature in the land of kangaroos heats up, general summer temps are 36-45 degrees c (97-113 F) So as you can imagine the cooling of my car is quite important.

So, driving around the suburbs in normal flowing traffic the car is fine, temp stays dead centre at 90c and oil wanders up a little (1/2 a bar) but no further. When driving in the city in stop start traffic however the temp just rises and rises, till the coolant boils over and the oil gets 1-1/2 bars higher than centre.

Info about the car, Timing belt, water pump and i assume thermostat done 30k ago, Viscous fan exploded so replaced with EFK which I always have on, motor has been coolant flushed and heat works well and gets up to temp in around 10-15 mins in normal conditions. Only overheats in stop start traffic. This has me thinking either the radiator is blocked or the EFK doesn't give it enough air flow.

After overheating i refilled with water and turned the EFK and thermo fan on and it stayed at 90c all the way home. I have ordered a new fan clutch and blade to replace the EFK (may install on front of radiator for emergencies) but what do you good people think it may be?

[crazyquik22023]

Sounds like a possible water pump problem to me, do the quick test and take off the line to the expansion tank and hold it over a bottle and have a friend hold it at 2500 rpms and see what kind of flow you get. Could also be a sticking thermostat. I'd guess one or the other.

[down_n_dapper]

I will take that method under advisement thank you mate!

Borrowed my mechanics infrared temp gun today and tested the rad, top was 108c and bottom was 52c, so over 50 degrees difference top to bottom, he believed it was atleast 30% blocked, causing circulation issues and lack of cooling, thoughts?

[Bordom]

Could be blocked, but Thermostat would cause the same thing. Do a flush and see how it helps

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