I had a Crown put in on my rear molar about a year ago, I have no tasting a very bad taste from that area when I chew on something hard on that side.. Does anyone know what is going on, I have also been feeling kind of ill.. Would this cause any health problems?

I had a Crown put in on my rear molar about a year ago, I have been tasting a very bad taste from that area when I chew on something hard on that side.. Does anyone know what is going on, I have also been feeling kind of ill.. Would this cause any health problems?