Over heating

[Davecamaro86]

I have an electric fan that comes on when the car starts. But it doesn't seem to do the trick.
if i'm crusing on the highway doing 80 for more than five minutes my engine wants to burn up. the only thing i think i'm doing wrong is leaving my 180dagree thermostat in during 95dagree heat. but still i wouldn't think that iwould still be running at 250 with the heat on.
i flushed the radiator and treated my system with something from prestone.

what i kind of think happen is that when how ever swaped the engine from a 305 to a 350 didn't put a bigger ratiator in.(if that even matters)



Bottom line is i don't want to buy a new RATIATOR. So if anyone has some info let me know.


THANKS

[Chevyracincamaro]

it only does it on the highway??

[4onFloor]

as far as i know, the 305 and 350 radiators are the same. check the air dam underneath the front of the car. you might also have a stuck thermostat

[SMOKEY818]

Go For A Bigger Radiator I Got Mine From A Crashed Iroc, Car Had Just Came In When I Was At The Junk Yard, I Got Mine For 50, It Was A Three Core Aluminum Radiator, It's Alot Better My Car Runs Alot Cooler You Could Also Get A New Fan Switch That Will Turn Your Fans On Earlier

[DaMoNe6969]

After the car overheats, check both of your rad hoses.. If the top rad hose is cool than you've probably got a sticky or faulty thermostat...

[Davecamaro86]

usually that when it over heat then when i get off the highway it it cools alittle but never back down to the t-stat temp

[Davecamaro86]

my top hose is hotter than the bottom. what does that tell me?

[DaMoNe6969]

Well that usually means that everything is operating correctly.. The coolant in the lower hose has just been cooled through the radiator, the coolant in the upper hose as just come out of the engine via the thermostat..


Check to see that the black plastic cowl is still in place under the car.. It'l be underneath the rad.. It directs air up at the rad while your driving.. Maybe didnt put it back in after the swap?

[Davecamaro86]

just checked it looks good. i changed the water pump 3 months ago and put everything back just where i found it. I have disconnected my egr valve and my smog pump but that shouldn't have any thing to do with the problem? Right?

[DaMoNe6969]

The EGR system will lower your engine temp a bit.. Not really sure by how much though.. I've always had it hooked up.. What condition is your rad in?? is it plugged up? Fins flattened out real bad?

The 180degree t-stat should be fine, so should the old rad, providing its in good shape

[Davecamaro86]

Its in good shape i would say fin are fine and i just ran treatment in it and then flush it

[DaMoNe6969]

hmm.. well this ones got me stumped?? When did the car start overheating?? Right after the engine swap? after egr blockoff?

[Davecamaro86]

When it started to get hot out side here in CT. Like 80 and above

[Davecamaro86]

Don't worry about it though thanks for all you advice.