Ensure your system is not full of gunk -- last time you replaced the fluid, was it brown and gunky? Have you ever used stop-leak? If so, be sure to do a super-flush, they sell the mixture at Wal-Mart and such...

 

I told you where it was in the other thread. It's on the thermostat housing.

 

very good chance that it's head or head gasket..i bought a 96 firebird w/ the 3.8 and it would sometimes run just fine and other times it would over heat and do some of the things you just said, but showed no other signs of cracked heads for over 2 months, but it turned out to have cracked heads.

 

I had the same thing happen with a Jeep Cherokee that I had. The problem was the radiator was stopped up as well as the heater core. I bought a new radiator and backflushed the heater core with a garden hose. No more problems.

 

Well I had fixed it. I replaced the radiator cap and flushed it. It was running great for the couple days I had the water and flush stuff in it. (I didn't drive it much) Well I put antifreeze in it one morning and it overheated and now I am pretty sure I have a blown head gasket. It was low on oil the day before maybe a half a quart and when I checked it it was a light brown and above the fill line. Like maybe a quarts worth not sure. It drives the same but harder to start or seems to be. Its currently not being driven I don't want to damage it further.

I am going to attempt to change the head gaskets myself but do you think the heads are cracked? It did get to 260 but I mean they are cast iron on the 3.4

 

u do not want to use all antifreeze, u want half water half antifreeze. if u use all anifreeze the cooling system does not transfer the heat as well. did u make sure there is no air in the system?

 

also 260 is not bad, not good but it shouldnt do damage to the motor. if u are using 100% anti freeze that could be it. drain half out and add water. see if it sill gets to warm.

 

It was all water in it. So i undid the lower rad hose and then filled the rad with antifreeze to dilute the water still in the engine.

I am not sure how to make sure no air is in the system on the 3.4

I am pretty sure it is at least a blown head gasket. I just got worried about what he said about his heads being cracked.

I saw some head gasket repair stuff you put in the coolant or whatever to fix it. Does that stuff actually work? It would be nice to not have to rip into that thing. There is not much space under the crawl.

 

no u dont want to use the additive in the coolant. only works for a short time if at all and can plug up the radiator and/or heater core. fix it right if its a head gasket.

 

should be a air bleeder valve/screw on the thermostat cover. unscrew it a little and if water comes out theres no air.