>*Sometimes when a grumpy old man gets annoyed, he makes noises like clearing his throat. Does grumbling or grunting define that action?*

Grumble: definitely not.  That consists of complaining words, it is not a sound.

Grunt: close, but that isn't it.  Grunt doesn't include throat-clearing, and it is an inhalation.

>*Is there a more appropriate word or an idiom for that?*

Yes.

**Growl**.

Done properly, it is deep in the throat.  

*Grunt* is high in the throat, and can be accomplished almost completely in the nose and mouth, that is, without involving the throat.  The best *grunt* is actually a heavy inhalation, with the nostrils and the back of the mouth loose, so that it vibrates with the air flow.

The best *growl* is accomplished with the mouth closed, as a harsh exhalation, through the nose only.  No work is done in the nose, all the work is in the lower throat, vibrating it.  The deeper the better.

A poor *growl* is high in the throat, see *harrumph* below.

A *growl* is a purposeful act, not due to accident or sickness.

Animals *grunt* and *growl*.

Young men used to be able to do it.

*Harrumph* is close, but distinctly different, it doesn't have that full throat-clearing sound that men can make, from deep in their throats.  I would describe *harrumph* as an amateur or beginner *growl*.  It is more of a sound of displeasure, whereas *growl* is a serious threat.

*Wheeze* has a proper meaning, the sound a person makes when they have emphysema, or when their windpipe is opened by some horrible injury.  It is accomplished as an inhalation, a strained one, with the throat contracted, or closed with a hole somewhere that is open. It causes alarm.

Men who can *growl* on demand can usually *wheeze* on demand, and it is just as scary to women and children, but for different reasons, growl being a threat and wheeze being an alarm.  For others, the *wheeze* is involuntary, due to accident or sickness.

*I know one woman who, after she got past the fear of my purposeful wheeze, wanted to learn how to do it.  Now she can wheeze much higher than I can, women's voices being higher, and all that.  She couldn't growl, mauch as she tried.*

Don't concern yourself with what writers write, they are making a royal mess of the English language. They are hardly an authority, and they commonly misuse words.  And that is separate to the use of the literary device: the purposeful use of incorrect words, to connote something.