Sometimes when i open my mouth wide i hear a grinding noise on the left. also i get bad headaches/neck pain on the left side randomly. is this tmj?

Could be: It is possible you have temporomandibular disorder. You should see a dentist to have it checked.

Yes: Yes those are certainly symptoms of temporal mamdibular joint pain and are treatable. Consult your dentist for treatment.

It sounds like it : May be that condition based on your symptom description. See your dentist for an evaluation.

YES: Yes these are each parts of TMJ dysfunction or tmd. You need to see a TMJ dentist or a dentist with a lot experience in treating bites. This can get worse. You can have the headaches greatly increase as well. This is the single most painful problem i see in my office. Go now.

Could be...: Crepitus or the sound of cartilage "grinding" is a symptom of temporomandibular joint disease (tmj). Other common symptoms include ear pain (referred pain), headache, neck and back pain.

Very good chance: The headaches and neck pain are common symptoms of tmj/tmd but don't necessarily mean you have a tmj/tmd problem. But your description of hearing a grinding noise when opening wide is a definite symptom. You should see a TMJ specialist.

Probably: Sure sounds like it. See a TMj expert for guidance. Any dentist can be a TMJ expert with the proper training and experience. Most commonly, oral surgeons, prosthodontists, and orofacial pain specialists. Ask your MD, your dentist and your dental society for referrals.