Is there an intramolecular hydrogen bond in guaiacol?
According to a quick calculation on the DF-BP86/def2-SVP level of theory, there is an intramolecular hydrogen bond with a strength of about $\ce{-26.6 kJ/mol}$ according to a quantum theory of atoms in molecule (QTAIM) analysis.



For an explanation of the evaluation of the bond strength see: E. Espinosa, E. Molins, C. Lecomte. Chem. Phys. Lett. 1998, 285, 170-173.
Analysis done with MultiWFN 3.3.8. Calculations with Gaussian 09 D.01.