hey just reading the thread my car does the same thing it runds good around town but on the highway doen about 75mph steady it heats up more than half way i got a new pump and a new 160*thermostat my fans are connected direct so they are on all the time also have the air deflector right any ideas of what it could be i heard it could be a minor blown head gasket i hope not its a rebuilt 355 about 6500 miles on it wuts the problem with the lt1s overheating?? anyone

 

Overheating that occurs at highway speeds is usually a water flow issue. When it happens at idle or stop and go, it is usually related to poor air flow.

 

Is your radiator flushed and clean? Dunno, that was my problem

 

So, when DOESN'T if overheat? I mean, is it ONLY when your at a consistant higher speed? if your waterflow was bad I would think it would me more aparrent at idle than moving at 75mph probably around a consistant 1800-2000 rpm.

 

I had same problem around same speed,On my car it was damn air duck that let air come up to radiator.Do you have it removed by any chance.

 

yeah i have the air duct its in the right place im going to go ahead and drain my radiator this weekend maybe this will help me i was planning on going to th f body cruise to south padre next week but with it overheating on the highway looks like its not such a good idea well thanks for the help

 

So your fans are running all the time???
The fans will stall the air coming thru the rad. That is why you trn them off over speeds. Know it sunds funny and didnt believe it till seeing it first hand in the windtunnel. Not saying its your problem but it is not helping.
Make sure your rad is flushed and you have 50/50 mix in it.

 

^^^ that actually makes sense. because usually a car will start to heat up at idle and cool down once it is moving. in my previous car(not a camaro) i blew my headgasket 3 times and each time when i noticed it was high is when i was stopped and once i started moving again it would drop a bit. however i never drove for any prolonged trips with a bhg lol, i would just try to limp my car home, so maybe on the highway it will overheat when driven on the highway for a bit. check your oil for coolant and coolant for oil. does your coolant overflow bottle ever overflow and spit coolant everywhere? although that would be a pretty severe bhg. i would check those fans first though.