Przed wyjazdem trzeba było podnieść maskę i sprawdzić silnik.

Because przed takes the instrumental case when it means before in time.

The basic noun is wyjazd. In the instrumental singular, it becomes wyjazdem.

So:

• wyjazd = departure / trip
• przed wyjazdem = before the departure / before leaving

This is the same pattern as in:

• przed obiadem = before dinner
• przed spotkaniem = before the meeting

Trzeba is an impersonal word meaning something like it is necessary, one must, or you have to.

To put that necessity in the past, Polish adds the past tense of być:

• trzeba = it is necessary / one must
• trzeba było = it was necessary / one had to

So było is what makes the sentence refer to the past.

You can compare:

• Trzeba podnieść maskę. = It is necessary to lift the hood.
• Trzeba było podnieść maskę. = It was necessary to lift the hood.

Because trzeba creates an impersonal construction.

There is no grammatical subject like I, we, or they, so Polish uses the neutral past form było. This is very common with impersonal expressions.

Similar patterns:

• można było = it was possible / one could
• warto było = it was worth it
• trzeba było = it was necessary / one had to

So było does not refer to a neuter noun here. It is just the standard past form used in this kind of subjectless sentence.

Polish often leaves the subject unspecified when the statement is general or when the person is obvious from context.

So trzeba było does not say exactly who had to do it. It just means that the action was necessary.

This can sound like:

• someone had to
• it was necessary to
• one had to

If you wanted to specify the person, you would usually use musieć instead:

• Musiałem podnieść maskę. = I had to lift the hood.
• Musieliśmy sprawdzić silnik. = We had to check the engine.

Because after trzeba było, Polish normally uses an infinitive to express the necessary action.

So the structure is:

• trzeba było + infinitive

Examples:

• trzeba było zadzwonić = it was necessary to call
• trzeba było poczekać = it was necessary to wait
• trzeba było podnieść maskę = it was necessary to lift the hood

This is a very common pattern in Polish.

They are perfective because the sentence refers to single, completed actions that needed to be done before leaving.

• podnieść is the perfective partner of podnosić
• sprawdzić is the perfective partner of sprawdzać

Perfective verbs fit well when you mean:

• do something once
• complete it
• tick it off as done

That is exactly the idea here: before leaving, those tasks had to be completed.

If you used the imperfective forms, the sentence would sound less natural in this context, or it would suggest more of a process/repeated activity:

• podnosić = to be lifting / to lift repeatedly
• sprawdzać = to be checking / to check repeatedly

Both words are direct objects, so they are in the accusative case.

But different noun types behave differently in the accusative.

maska

This is a feminine noun.

• nominative: maska
• accusative: maskę

So after podnieść, you get podnieść maskę.

silnik

This is a masculine inanimate noun.

For masculine inanimate nouns, the accusative singular is usually the same as the nominative.

• nominative: silnik
• accusative: silnik

So:

• sprawdzić silnik

Yes.

In everyday Polish, maska can mean:

• a face mask / disguise mask
• the hood/bonnet of a car

In this sentence, the car context makes the meaning clear, especially because of sprawdzić silnik.

So podnieść maskę is the normal way to say lift/open the hood.

Because Polish has no articles.

There is no direct equivalent of a/an/the in normal Polish grammar. Whether something is definite or indefinite is usually understood from context.

So:

• maskę can mean a hood or the hood
• silnik can mean an engine or the engine

In this sentence, English naturally uses the hood and the engine, but Polish does not need any extra word for that.

Yes.

That is a very normal structure in Polish. One expression of necessity can apply to two or more infinitives joined by i.

So the sentence means that both actions were required:

• podnieść maskę
• sprawdzić silnik

You do not need to repeat trzeba było before the second verb.

The word order is fairly flexible.

Przed wyjazdem is placed first because it sets the scene very naturally: first the time frame, then the required actions.

But other orders are possible, for example:

• Trzeba było przed wyjazdem podnieść maskę i sprawdzić silnik.

That still sounds fine. The original version is just especially natural because it starts with the background information.

Yes, but the nuance changes.

trzeba było

This is impersonal and general:

• it was necessary
• one had to

musieć

This is personal and tells you who had the obligation:

• musiałem = I had to
• musieliśmy = we had to
• musiał = he had to

So:

• Przed wyjazdem trzeba było podnieść maskę... = a general statement about what had to be done

• Przed wyjazdem musieliśmy podnieść maskę... = specifically we had to do it

Both are correct, but they are not used in exactly the same way.