ACT Composite Score 36, but bad essay score? Does this matter?

I got a 36 as a composite score for my ACT (36 Math, 36 Science, 35 Reading, 35 Writing), but only an 8 on my essay. How detrimental will this be when I apply to colleges in the fall (shooting for Ivy Leagues and other top colleges)? I'm definitely going into the math/science field, such as engineering, so will it have less of an impact? I was so happy when I got my composite score, but now I'm kind of bummed.