If by "inner ear" you mean the ability to improvise without actually hearing what you play, and still knowing pretty much exactly what it sounds like, then nothing even close to John Coltrane's skill level is needed. Even I can do that easily. If you can sing an improvised line and then repeat the same line correctly with your instrument, then you played what your inner ear told you. Right? But if by "inner ear" you mean some magical special quality of being able to draw from an inexplicable source of new kinds of things that were previousy not even in your vocabulary, then I don't think Coltrane did that. In his playing he utilized things that he had mastered through practicing.
I think the "inner ear" ideal is a myth and a misconception. As a human you are a psycho-physical system, and the things you play when improvising (or otherwise) are a result of many interdependent physical and psychological parts and layers, including fingers, arms, nerves, memory, hopes and fears and everything. You can even include the instrument, the environment, the acoustics and the audience in the system. Good musicians seek inspiration and feedback and feelings from many things you might consider external factors, but they do affect the result, it's just natural, and it's nothing to be ashamed of. Whatever the chain of events was that led to the music you produced, it's still your music. What makes you think you could know the chain of events behind Coltrane's music, and which of those events happened inside some mystical "inner ear" area, and which of them happened outside of it?
However, since you posted this question, there might be something you're seeking that could be improved, and that's expanding your perspective when playing. In terms of levels of abstraction, what is the "domain" you're operating in? What things do you think you're allowed to change - what is your musical device? Instead of just obeying plans coming from a higher level, you could start to take ownership of the higher-level things and start playing with them as your creative toys.
For the sake of argument, let's assume that there's this kind of a hierarchy of abstractions, from physical to logical and abstract. This is from a Western style "harmony and notes" way of thinking, and there are many more aspects to the final musical outcome like the whole world of rhythm, rhythmic tension and resolution and ambivalence etc., timbres, ... lyrics and words and all that. But each of those areas and musical dimensions has a similar structure of layers between concrete and abstract. I'm sure people have opinions on the validity of this structure, but the exact model is not relevant. You can imagine your own better model.
- physical finger and arm movements
- __< exact notes
- ____< melodic+harmonic+rhythmic "implementation", chord voicings
- ______< chord and voice movement
- ________< harmonic turnarounds, "what is the key/mode and on which side are we leaning"
As you know, these layers are all inter-connected. If you change a physical finger movement, it may change the note, which may change the chords and turn the harmony around. Or it may just sound like a mistake. Each layer also adds details that can be very important to the whole, but that the higher layer doesn't say anything about. The chord progression doesn't say anything about exact picking/fingering patterns or even voicings, etc.
Now the important question is, in which of those layers are you able to operate fluently? What is your musical domain? Do you think that you're not allowed to change the chords? The turnarounds? You say that you play too much pre-learned patterns ... but on which layer of abstraction are those patterns? Maybe you could play almost the same patterns or licks, but with different chords and timing? Can you play a minor lick in a major key?
I think it's a good analogy to think of improvisation as live arranging and composing. Which layers do arrangers and composers operate on? Step up from the lower levels of hierarchy! :) Don't think like a worker or soldier blindly obeying plans and instructions coming from higher up, think like the planner. Maybe even like the board of directors! :) Start playing around with chord progressions, and start setting musical goals in terms of what happens on the more abstract level. Sometimes you might settle for the exact original written chords for various reasons, but it should be your own informed decision. You should have a sense of what is essential for the tune, and the particular feeling and interpretation you want to deliver. If your reason for using the exact written chords verbatim is that "I'm scared and I don't know what might happen if I changed them", then that's a weakness you should start improving. The same thing applies to all other aspects of musical expression, but for some reason I've noticed that harmony is often an area where players fall short.
This is a good place to mention scales and the "chord-scale system" thing that was talked about recently. Scales are lower-level musical objects! If you're a good jazz improviser, you have to think higher than that. Even if you knew how to apply the chord-scale system that gives you a list of possible scales, which one do you select? Why and using what information? Randomly? Think higher! :) So, to become a good jazz improviser, you have to become very fluent in the higher layers. Make your own voice leadings and chord progressions. Play the same melody 10 times with different chords every time. Can you do that? The primary role of jazz comping is not to provide "harmonic context", which locks down chord choices and limits the soloist's creativity. Comping provides rhythm, so the soloist can invent her own chords. And she can do that, because she has mastered the higher levels of musical elements.
Maybe I should emphasize that you don't toy around with chords just to show off that you can. That's what junior pop/jazz school students do, and it belongs to that phase of musical development. (Or at least I hope they play around with chords and don't just apply these chord-scale systems brainlessly with the sole purpose of avoiding blatantly wrong notes.) You develop the higher-level skills to know what is important and what isn't, and to know how to create tension and release, expectation and surprise. You're telling a story, or more like, paraphrasing a story. How do you know which notes to emphasize? If you can use only two notes, which ones do you pick, and what's your goal in selecting exactly those notes?