Motorrommet er rent og uten rust.

In Norwegian, compound nouns are normally written as one word. So motorrommet is made up of:

• motor = engine / motor
• rom = room / compartment
• -met = the definite ending

So motorrommet literally means the engine room or the engine compartment, depending on context.

That ending shows the noun is in the definite form: the engine room.

The base noun is et motorrom (an engine room / engine compartment).
Because motorrom is a neuter noun in Norwegian, its definite singular form is:

• et motorrom = an engine room
• motorrommet = the engine room

So instead of using a separate word for the, Norwegian often adds it to the end of the noun.

Er is the present tense of å være (to be).

So:

• er = is / are

In this sentence, it links the subject and the description:

• Motorrommet er rent ... = The engine room is clean ...

Because rent agrees with the noun motorrommet, which is neuter.

The adjective ren means clean, and its form changes depending on the noun:

• en ren bil = a clean car
• et rent motorrom = a clean engine room
• rene biler = clean cars

Since motorrom is a neuter noun (et motorrom), the adjective becomes rent.

Because in Norwegian, the definite article is usually attached to the noun itself.

So:

• rommet = the room
• motorrommet = the engine room

Unlike English, Norwegian often does not need a separate word like the in this kind of sentence.

Uten is a preposition meaning without, and rust is a noun meaning rust.

So:

• uten rust = without rust

This is a very natural Norwegian way to describe something as being free from rust. It is not using an adjective here; it is using a prepositional phrase.

Because rust here is a noun, not an adjective.

• uten rust = without rust
• rusten = rusty
• rustfritt = rust-free

So the sentence chooses the structure:

• clean and without rust

rather than:

• clean and rust-free

Both can work in Norwegian, but they are built differently.

Yes, absolutely. Motorrommet er rent og rustfritt is a natural alternative.

The difference is mainly style:

• rent og uten rust = clean and without rust
• rent og rustfritt = clean and rust-free

The second version is a bit more compact because rustfritt is an adjective.

Because this is a basic main clause, and Norwegian main clauses often follow a pattern that looks very familiar to English:

• Subject + verb + complement

So:

• Motorrommet = subject
• er = verb
• rent og uten rust = description/complement

That gives:

• Motorrommet er rent og uten rust.

This is one of the easier Norwegian sentence patterns for English speakers.

A rough pronunciation guide is:

mo-TOR-rom-met er rent og U-ten rust

A few helpful notes:

• r in Norwegian may sound different from English depending on dialect.
• og is often pronounced more like å in everyday speech.
• rent ends with a clear t sound in careful pronunciation.

If you want a very rough English-style approximation, you could think of it as:

moh-TOR-rom-met air rent oh/aw OO-ten roost

But that is only approximate, since Norwegian sounds do not match English exactly.