Engine Mechanical problem
1988 Other Plymouth Models 4 cyl Front Wheel Drive Automatic 85000 miles
the engine shakes a little, like a spark plug is not firing, but only sometimes and is worse at some times. The car overheats sometimes but not all the time steam is coming from the coolant overflow and oil fill cap and somewhere I cant see in the back of the motor
Do you have a 2.2 or 2.5 single over head cam engine?
If so, I may have some bad news for you.
They are prone to developing a crack between the valve seats.
And if that doesn't happen then they warp and the head gasket looses its seal.
Either one of these cases would allow hot combustion chamber gases into the coolant system. (Steam coming from overflow tank)
or low compression, and keeping the cylinder from firing.
They can be tricky to verify sometimes.
Under just the right conditions, the leak doesn't show up at room temperature.
So sometimes a leak down test, or pressurizing the coolant system doesn't show anything.
But with you leaking coolant out the back of the engine, I suspect a blown head gasket.