Hi Jim,

You have what's clinically called an:

Olfactory Nerve Disorder: this means that something has affected the main nerve responsible for "smell"...which is why you keep smelling 'exhaust fumes'.

Here's a link:

http://www.merck.com/mmhe/sec06/ch097/ch097a.html

Here are some possible causes: [I believe the nausea & headaches are related too]

• (Internal) Sinus infection
• Sinus or nasal polyp
• Intracranial cyst or tumor [impinging on Olfact. nerve]
• Exposure injury to Olfact. nerve

I strongly advise that you make an appt for a detailed exam by a Neurologist; he will probably order some tests [eg head CT or MRI scan] to help establish the correct Dx, and then start you on the approp therapy.

Good luck.

I DO hope you found my Answer to be helpful regarding your medical condition. IF SO-please hit **ACCEPT** as you read this Answer. THANKS for your trust!

(feel free to ask a followup Q, if needed)

Best Wishes for Your Health,

--Dr. Steve, (Your Online Family Doctor)