Overheating Issue - SBC

[Newman]

I have an issue with my Nova, it never ran hot before, but lately it's been overheating when I drive around town. It's fine when I'm outside of town driving between 25 and 50 (or faster) but when I'm just cruisin in and around the slower parts of town it's getting hot, even on a nice cold evening. Tonight we reset the timing, removed the stock radiator and replaced with a much larger aluminum race radiator, and went for a drive.....SAME RESULT! So we took it home, put in a new 160 degree thermostat and went for another drive....still HOT!

We're thinking our next plan of attack will be to try a new water pump (original one is on it now). Any other thoughts on what would be causing us to run hot in and around town????

[acelr8]

fan clutch and head gaskets are the first two things that come to mind for me ?

[Newman]

Sorry no clutch, it has a plastic flex fan, pushes lots of air. Can't see it being head gaskets either or it would just be hot all the time...?

[Chevyfever]

check lower radiator hose may be partially collapsing

[Newman]

Rad hoses are good, nothing is air locked...the only thing we can think of at this point is the water pump, either the pump or the belt slipping at low rpm???

[Salvatore]

I doubt if it is the belt. Try your cap and also does it boil out? Is the gauge correct? When you open the hood does it feel/smell hot? Also the fan better be pulling lots of air and not pushing it. Is the car running to lean?

[Norm reynolds]

From what you posted it can be 2 things water pump going bad and the # one thing is air in the system I all way found getting the air out a challenge but a friend turn me on to a
spill free funnel What it does it goes on top of the radiator and you fill the radiator up and tun the car ( leave coolant in the funnel) as the car warms up air will be released in the funnel It does NOT make a mess and after the air is out let the car cool down what coolant is in the funnel will get sucked back it to the radiator
I got mine on Amazon for about 26 bucks
after years trying to get the air out of a cars radiator I have found that this is one of the best ways to get the air out

got mine here
funnel (http://www.amazon.com/gp/product/B001A4EAV0/ref=oh_details_o00_s00_i00)

[Newman]

Issue solved, after trying new rad cap, thermostat, new water pump, and getting the rad flushed it turned out to be a bad plastic flex fan, put my old fan back on and problem solved! Thanks for the helpful suggestions.