This picture is of a supercharged motor but whatever I'm saying here is the same for both motors.
If you see oil pooling or coolant pooling on either the front of back side on the lower intake manifold, the gaskets are failing. You can see the oil pooled up in notch there and coolant in the other.
So if you said you spray coolant on the front side, look on the backside to double check the condition. If they have never been replaced and car has over 100k miles, you are just playing with fire. They will fail, it's not a matter of if but when.
