Have a ZD Fairlane running a c10, 302 Windsor (approx 145000 miles).
Overheated 2 wks ago (went to about 3/4 on temp gauge).
Very unusual for this car considering it always sat at about 1/4.
Had radiator inspected and cleaned out.
Flushed the engine water compartments totally and got rid of all the dirty water etc.
Installed a new thermostat (77 Deg)
and a 7 blade flex fan. It also has a shroud in front of radiator.Added coolant etc

Whilst in traffic the temp stays at 1/4 until I stop for traffic lights or in heavy traffic.If I put it into neutral at the traffic lights the temp stops rising (obviously revs are higher water is getting around)

Went on a highway drive to Traralgon the other day and it was fine until I started to flaw the car whilst overtaking etc and doing about 60-70 mph on the trip.
The engine temp started to rise slowly at that constant speed and it went just over the 1/2 way mark on the gauge.

As long s I can remember the car never did this. Was always running cool.
It doest use much oil (it maybe needs a top up 300-500ml every 2 to 3 months).
Oil is pretty clean (changed about 2 weeks ago)so it might not be a headgasket.
Water is not missing from the coolant system as I check it everyday and it sits about 1/2 thumb under the cap.

Is this normal for 302 Windsors
ie to generally heat up.

Any feedback/suggestions will be appreciated

Chris

Yep, water pump is where I would look next too. The impeller fins that move the water might have corroded.

Thanks Brenden for your reply

Appreciated.

Will check water pump

hey same proberlem in a ZD here but a 351 celeveland, new water pump same thing, flushed radiator same thing, new thermo sammme thing, and new 7 blade fan n yer same thing, but i got this thermostat which brought it down to half itss called a tridon Hi-Fl

I have a Zd and yeah mine genrally sits around 1/4 to half but never goes above. (302ci)[email protected] (New Zealand)