could also be your cooling system not doing its job. The car might be running hotter than normal. Check to make sure your coolant level is correct. Any noticable leakage?
[Rebuilt M62TU, Shortshifter & ZHP, Spacers, BC Coilovers, Hawk Pads, Stainless Lines, 20% Tint, & Ebay cupholders. Y Res delete, control arms, bushings, and sways coming soon!]