ok i have a 99 galant es 4 cyl and recently the car was shaky at start and idle now its still shaky at start and idle and after running for a little the temp gauge goes up to about half way and the car just stalls and wont run till it cools almost all the way but then stalls as soon as it warms up again I replaced one of the coil packs and this did not help. any help would be greatly appreciated. thank you!

 

Pull your coolant temperature sensor and see if it is discolored or cracked. Replace it if so. I know it seems strange, but it affects an engine in the strangest ways when it goes bad. If I were a betting man, thats where I would put my money. A 15 dollar part. If it looks good we'll have to look elsewhere. As far as coil packs go, is there 1 coil pack per cylinder? or 1 for 2 cylinders? They don't go bad very often. Just pull 1 plug wire (at the spark plug) at a time (while the engine is running) and listen for a rougher idle than it was before. It may die all together. If you hear no change, thats the bad one.