My brother has a 1986 Firebird with a 2.8L V6. About 15 minutes after he starts driving, it starts overheating. We've flushed the radiator, no help. Checked the air dam, and that's in good shape. The fan doesn't come on until about 260 degrees. So, we changed the coolant temp sensor, which didn't change a thing. Any suggestions would be awesome. Thanks.

 

take the radiator cap to a autoparts store and have it tested. Most of the time they don't hold pressure and end up dumping coolant all over the place. It must hold pressure without any leaks.

 

Low temp thermostat,get better fan or manual switch and you can add Purple Ice or Water Wetter in to the radiator.

 

We wired the fan, and added Water Wetter and now she's back down to 220 degrees when driving. When stopped, it'll go up to 240 degrees, and then when we start moving, it goes back down to 220 degrees. It's a big improvement. Anything else y'all think of, let me know. Thanks for all y'alls help.

 

I would check your sending unit if the fan does not come on until your temp guage reaches 260. You're probably running a little cooler than you think.