Thanks for the troubleshooting tips.

The codes that were showing up were as follows:
P0455- Evap Large leak. The dealer said that the "EVV" had failed. Some kind of emissions valve. Shouldnt affect performance.

P0171- Fuel mixture lean. the shop suspected this was due to my "not so cold" air intake and the autozone spectre filter. I may have got a little much oil on it and could be affecting the MAS.

 

I also think you need to do a coolant pressure test. I would also fill your coolant, and mark the level with a sharpie marker (after you have driven it a while and its fully warmed up). Then drive around for a couple weeks, and monitor that coolant level closely, if it drops, then you got a leak somewhere, if it holds totally steady, you do not have a leaking head gasket.

I'm just going to throw this out there....a few months back, I went to use my heater, and it didnt work, I thought, GREAT....drove it around, and it started working, then stopped. Then it was fine for a while, and about a month later a jackhammering noise came from my dash. Turned out it was the actuators that controlled the climate/ temp went bad.

Although, I know exactly what you mean with the heat coming in and out as you drive, and it does sound like it was probably air in the system...but I just wanted to throw that out too.

 

the dealer should know that all gm cars have 100k powertrain warrenty baught new or used. if they are expecting you to pay dont bring up the hundred thousamd natural powertrain warrenty gm gives there cars that there falls under that warrenty. if they didnt go by the miles and the year of the car it should have that warrenty. the warrenty gm offers for the power train is awsum till the dealer said i expect you to pay bring up the hundred k mile power train if the service writer say it doesent apply say i will be complaning to the general manager and also be loud about it

 

X2 on the compression test. At least that will show you exactly where the problem is.

 

The 100K warranty is only on 2007+ GM models.

 

I had my dad speak to our local mechanic who has done work for our family for years and is a trusted source. After giving the description of my issue the mechanic, he said that it was a bad intake gasket and that he has replaced several of them on the 3.9 engine displaying similar symptoms. He also quoted about $400 to do the work. The dealer i originally took my car to is asking around $800 to do an intake gasket. Dont believe i will be going to them again.

Ill check my coolant levels and top off and watch it for a couple weeks before i head home (aprox 300 miles) and have the mech look at it.

 

Have you had to add coolant in the past? I'd find it hard to believe that you have a leak big enough to trip a SES light without ever loosing coolant.

Can't say I've ever done anything with the heads on this car, I have the same engine, but I know I'm not a big fan of working on it. I don't mind my other two vehicles but this one is a bit too tight for easy access.
I still have a leaking front main engine seal that needs fixed.

 

My SES light wasnt about any coolant leak. That was just a coincidence it would seem and the reason i took it to the shop in the first place. Ive never had to put coolant in it myself, but to be honest ive never checked it until a few nights ago and it looked fine according to the markings on the overflow bottle. Ive never noticed any coolant leaks on the ground underneath it or anywhere on the motor when im under it to change the oil.

 

You know I had a coolant weep about 3 months ago, it barely leaked, took a month to notice any drop in the level. But I took it in, prepaired to hear that my intake gaskets, or head gasket was leaking. They pressure tested my cooling system to find that my radiator cap was leaking coolant under pressure. So a new cap for $17.99 and the problem is fixed. Doesnt leak a drop now!

 

Got it fixed! Took it to our local mechanic and after discussing the symptoms with him a little more came to the conclusion that it was the heater core gummed up. He told me that coolant used that year has a tendency to gum up during the summer and when my car was idling it wasnt producing enough pressure to push through, but when accelerating it could. Flushed the heater core for $20 and noticed the difference right away.