Remove head change gasket and replace head, pretty simple.
there is no lower intake gasket, only a front and rear gasket
video to learn how to replace the engine gasket..upper & lower gasket for 1999 Monte Carlo.
Probably just a worn belt. The 99 Galant upper belt is easily tensioned and the lower belt is not too difficult to replace. A fair shadetree mechanic can replace both in 30 minutes for less than $20.
Remove upper and lower engine intakes. Tie back or label tubes so not to loose reconnections. Once everything is remove the gasket is exposed. Pull gasket replace, then return intakes and labeled tubes.
I'll assume Lower Intake Gasket, since they tend to cause vacuum leaks. Get a manual from Autozone and expect about 4 hrs labor, you need to take off the upper intake manifold just to replace the Lower Intake Gasket. Probably should change/clean the PCV valve while ur in there. Good luck, man.
get yourself a chilton or a haynes manual. it should explain it all
Drop the lower transmission pan Clean pan Replace filter and gasket
blown head gasket is the usual reason for oil in coolant or radiator. sad part is if you have already replaced intake gasket, u wasted your money as you will have to replace again when you fix head gasket
Replace the head gasket with a thicker one, this would lower the compression ratio.
I have a Mits Galant 1990 A/T and recently repaired a leaking washer pump. The washer pump in my Galant is attached to the lower part of the water reservoir. You need to remove the electrical connection to the pump and remove the reservoir. Afterwards, you can remove the washer pump and replace it with a new one. To ensure you have no leaks when you install the new pump, I suggest you line the holw of the reservoir (the hole where the pump goes into reservoir) with silicone paste or any other sealant. Replace the reservoir and the connect the electrical connection.
The 1996 Mitsubishi Galant OBD 2 port is on lower edge of drivers dash next to center console
by the lower intake manifold while you are doing this you should replace the intake manifold gasket anyway because it will leak sooner or later.