Problemas com ionic .present();

Quando estou utlizando o content e o presente, me apresenta os seguintes erros no visual studio code:

Content: 'Argument of type '{ content: string; }' is not assignable to parameter of type 'LoadingOptions'. Object literal may only specify known properties, and 'content' does not exist in type 'LoadingOptions'

e para o present: 'Property 'present' does not exist on type 'Promise'. Did you forget to use 'await'?ts'

Alguém sabe me dizer como posso corrigir isso ? Obrigado desde já.

 constructor(public navCtrl: NavController, 
              private _htpp: HttpClient,
              private loadingCtrl: LoadingController) {

    let loading = this.loadingCtrl.create({
      content: 'Aguardando carros...'
    });

    loading.present();