The solar p-mode spectrum of very low l has already been measured with high accuracy for a sufficiently long period of time to permit the search for solar cycle variations. The longest one-site velocity observations for low l solar p-modes (Tenerife) has been used to measure the l = 1 mode splitting at the two extremes of the solar activity cycle. The results found exclude the rigid body rotation for the Sun. When taking the extreme values measured for the splitting, a solar core rotation between 2 and 4 times larger than that at the surface is obtained. Also, the observational results indicate an increase (1.3-2 times) of the rotation rate at the maximum of the solar activity cycle.