Pontiac Repair: 2000 Bonneville SLE, oil pressure gauge, upper intake manifold

Question
I have a 2000 bonne that is leaking antifreeze out of the left side of the motor, I just bought the car recently and there is additive in the antifreeze not realizing that when I bought it, the car has never overheated or even ran hot for that matter, no pinging or anything no lifter noise, do you know if that could be the upper or lower intake gasket?  How do I know if the head gasket is bad also?  another thing, my oil pressure gauge sticks on 120psi constantly how do I fix that? also another thing my gas gauge only works when its over a quarter tank and only works when idling at a stop. when I start to drive the gauge stops working it will float to a half or full or what ever but as soon as I stop it will read correctly within 30 seconds, also another thing, do you know what volt bulb are in the LCD display for the factory stereo so i can sauder new ones in the display?

Answer
Hi David.

The coolant leak is more than likely the upper intake manifold plenium is warped and leaking out under the throttle body. This is VERY common. replace the manifold and gasket. In extreme cases the lower gasket will leak but not that common. Head gaskets are not common on these either unless they over heat. for the fule gauge it needs a fule levle sensor in the tank again VERY common. As for the oil pressure gauge that is not that common but I would guess at a sending unit on the engine but it could be tha gauge as well You would need a special tool to check that out though "for the gauge"  The radio needs to be repaired the bulb is not replaceable We do not fix radios here we send them out to an ac delco reman facility.
Good luck :)