I have a 1996 Camaro with a V-6 engine/manual transmission.
When I drive it and sit in traffic, it begins to get hot.
This has started fairly recently. I took it to the Chevrolet
dealer and they replaced the water pump. It was leaking (I
visually verified that). They claimed my problems were fixed.
It is still getting hot. Not boiling over hot but the temp
gauage still gets to the half way point. Before it would go
only 1/4 of the way from the cold to hot. I keep thinking
head gasket but I have no evidence of that, ie peanut butter
in the oil or any oil in the coolant. Can someone give me an
idea of what this might be?

Thanks in advance
Gary