Ohjaustanko tuntuu löysältä, kun ajan.

Because tuntua usually takes an adjective in the ablative form (-lta/-ltä).

So Finnish says:

• tuntuu hyvältä = feels good
• tuntuu pahalta = feels bad
• tuntuu oudolta = feels strange
• tuntuu löysältä = feels loose

If you said Ohjaustanko on löysä, that would mean the handlebar/steering bar is loose as a fact.
But Ohjaustanko tuntuu löysältä means it feels/seems loose to the speaker.

Tuntuu is the 3rd person singular present form of tuntua.

In this kind of sentence, tuntua means to feel or to seem:

• Tämä tuntuu raskaalta. = This feels heavy.
• Se tuntuu oudolta. = That feels/seems strange.

So here, Ohjaustanko tuntuu löysältä means that the steering part gives the impression of being loose.

Finnish often leaves out the subject pronoun when it is clear from the verb ending.

• ajan already means I drive / I am driving
• the -n ending shows 1st person singular

So:

• kun ajan = when I drive / when I’m driving
• kun minä ajan = same meaning, but with extra emphasis or contrast

In normal speech and writing, leaving out minä is very common.

Ajan is the present tense of ajaa.

Finnish present tense often covers both:

• I drive
• I am driving

So kun ajan can mean:

• when I drive (general/habitual)
• when I’m driving (right then, in context)

The exact meaning depends on the situation, not on a separate continuous tense like in English.

It does not need an object here.

Ajaa can be used on its own to mean to drive:

• Ajan. = I’m driving.
• Kun ajan, en puhu puhelimessa. = When I’m driving, I don’t talk on the phone.

If needed, Finnish can add an object:

• Ajan autoa. = I’m driving a car.
• Ajan rekkaa. = I drive a truck.

In your sentence, the important idea is simply while driving, so the object is omitted.

Here kun means when.

It introduces a subordinate clause:

• kun ajan = when I drive / when I’m driving

So the structure is:

• main clause: Ohjaustanko tuntuu löysältä
• subordinate clause: kun ajan

Very literally: The steering bar feels loose when I drive.

Yes. Ajaessani means while driving or when I’m driving.

So you could say:

• Ohjaustanko tuntuu löysältä, kun ajan.
• Ohjaustanko tuntuu löysältä ajaessani.

The version with kun ajan is usually more straightforward and beginner-friendly.
The -essa/-essä form with a possessive ending (ajaessani) is also common, but grammatically a bit more advanced.

Yes. Ohjaustanko is a compound noun:

• ohjaus = steering / control
• tanko = bar / rod

So together it means something like steering bar or handlebar, depending on context.

Finnish uses compound nouns very often, so it is useful to get used to spotting the parts inside a long word.

Because the subject is ohjaustanko, which is singular.

• ohjaustanko tuntuu = the steering bar feels
• ohjaustangot tuntuvat = the steering bars feel

The verb agrees with the subject in number.

The given order is the most natural neutral order:

• Ohjaustanko tuntuu löysältä, kun ajan.

You can move parts around for emphasis, for example:

• Kun ajan, ohjaustanko tuntuu löysältä.

This still means the same thing: When I drive, the steering bar feels loose.

Finnish word order is more flexible than English, but the neutral order is usually best unless you want to emphasize something.

Because Finnish has no articles.

So ohjaustanko can mean:

• a steering bar
• the steering bar

The context tells you which one is meant.
That is normal in Finnish.

This is an important distinction:

• Ohjaustanko tuntuu löysältä = The steering bar feels/seems loose.
• Ohjaustanko on löysä = The steering bar is loose.

The first one describes your perception or impression.
The second one states it more directly as a fact.

In many real-life situations, tuntuu löysältä is a natural way to describe a mechanical problem you notice while using something.