ok my cousins lt1 is over heating although not usually while actully driving

weve changed the thermo to 160
the fans turn on
we ran a flush through it
pulled the haeter core and looked for clogs
bled the system added new coolant
checked the pressure and replaced a worn out cap
checked all cylinders for pressure to check for head gasket leak
waterpump was replaced about 1.5 months ago

i want to say we did some other stuff but cant remember what
please help

 

If it overheats when idling or moving slowly in traffic, but not when you can drive along at a steady speed, then I'd suspect the fan(s) and/or shroud of being less than helpful.

 

when he drive its fine even in traffic but when he stopped for gas and shut the car off it started boiling over and then when he started it it was in the red and we had to let it cool down before we go any where

i guess thats a better statement of how its overheating

 

I'd like to know waht resolves the issue. I am having a similr issue with mine. Fine as long as I am at highway speeds, but if I get stuck in traffic, it climbs quickly!! I recently replaced the water pump, putting a 160 thermo in tonight along with another ECM that has been tuned forhte 160 thermo.... Was considering a flush, but I dont see any issues with the coolant itself...

ADam G