I have a 2001 S40, Iwas listening to a conversation between my brother and dad. They were saying that the timing belt need to be
changed at 100,000 miles. I thought it was 110,000, I have 113,000 miles on my car. If it is at 100,000 miles, have I done any damage. I am not for sure what a timing belt is. Also, I am going to have my maintanence done next month.
Thanks
Tia[]

 

if you are over 100,000 you definitely need it replaced...its going to cost you quite a bit to have it done as its a sensitive job, do not go much longer without it being replaced...timing belt is one of the most important mainetance items not to forget....!!!!

 

Tech recommends changing it "at 70,000 instead of 105,000 as Volvo recommends": https://volvoforums.com/m_81259/tm.htm

However, you haven't done any damage yet. The damage is done if/when the belt breaks (and the pistons slam into the valves) resulting in an overhaul of the engine.

A timing belt is simply a belt that turns some pulleys, the upper pulleys driving the valves of which one set lets air into the engine (intake) and then after burning, the other set opens to let exhaust out of the engine. The lower pulley is rotated by the pistons. The belt makes sure the timing of the valves opening and closing properly matches the pistons motion. If the belt breaks, the pistons keep moving, but the valves stay put. When that happens the pistons hit the valves and can cause extensive damage.

 

The engine is an "Interference" design which is described in the previous post. Several of the older Volvo's ('97-00 850 and V70) had an issue with the timing belt breaking at 80-85K mileage range due to faulty tensioners. It's always best to spend the extra dollars to have both the belt and the tensioner replaced every 70K.