Just a couple problems..

Ok, starting to run into more problems :banghead: ...

1st - I know I have an oil leak, about a puddle 2 inches diameter, over night. Mech: suspects its a gasket in the intake manifold. Me: I think it drips somewhere near the oil pan.

2nd - Car heats up QUICK, sits at the line before the red one goes up n down. Could it be because the oil leak, or lack of coolant? Or thermostat, possibly?

3rd - If I fill my radiator up, to the top, with coolant, it leaks.. alot..
I cant really locate where the leakage is coming from but it is some where directally under the battery. I see a puddle of coolant under the battery, in a tray like spot. What is the difference between using water and coolant?

Thanks for any and all the help in advance..

1) GM Engines are notorious for oil leaks from an intake. You can easily figure this one out for your self. simply work your hand back there and run your finger along the back edge of the intake and see if you stike oil. the front edge of the intake is even easier - you can visually see that. also another possibility is the rear main seal, but i would say your mechanic is right about this one.

2 & 3) I would say the problems are very closely related.
If your radiator is "known" to leak and your coolant level gets low then the car is going to run hotter from the reduced cooling capicity. However low the coolant level is in the radiator is all of the cooling you will get - the exposed area just isn't used at all since there is no circulation there.
Plus if the radiator is leaking, you probably aren't able to keep the system pressurized enough and subsequently lowering the boiling point of your coolant.
Check the plastic end caps on the radiator for tiny cracks. They may not leak while it is cool but when heat is applied they will expand and open up.

Finally, a 50/50 mix of coolant and water is recommended.
Water alone will not give the proper cooling capaicity you need, since its boiling point is lower than the 50/50 mix, Plus you wont have any freeze protection for winter.

Rear main seals ALWAYS go on our cars, but mine isn't that bad and it's been leaking for over 2 years. That is my first guess, intake manifold my 2nd.

the 4th gen battery mount is molded onto/above the coolant overflow reservoir, I'm guessing if the leak is right below the battery then that's it.

it's definetly the resevoir because i had to change it on my car i punctured it from the bottom but the part only cost me 48bucks from the dealer and took about five minutes to install.

Thank you guys for the help, im deffinatly going to look in to it.

Ok, I still cant find the "source" of the leak cause the engine is covered in a coat of oil, so its kinda difficult. I tried to spay it off with a hose, got alot but not all. I also have some engine degreaser that I am going to try using. I have some pictures from where it was dripping, I dont know what they lead up to, so i need some help. :biggrin:

http://i19.photobucket.com/albums/b151/x8xViperx6x/OilLeak001b.jpg
This is where it is dripping off of.

http://i19.photobucket.com/albums/b151/x8xViperx6x/OilLeak005.jpg
http://i19.photobucket.com/albums/b151/x8xViperx6x/OilLeak002.jpg

find the highest place the oil is at... oil wont travel up.... and the rear main seal is the most common area for an oil leak (not saying this is your case but its the most likely cause)