I have a Volvo S80 2.5 T, 2008 model. Some time ago the serpentine belt broke while driving and some the cylinders and valves got damaged and needed to be replaced. This happened at around 115,000 km. About a year after I got it back from the repair shop, same thing happened again. Back to another repair shop where they specialized in Volvo (not a dealer). They fixed it, but same thing keeps happening. However, I check it regularly now so it does not do any damage to the engine, other than damaging the serpentine belt. I assume it is a problem with the alignment, but nobody is able to fix it. The car has never had an accident. Also, there are no official Volvo repair shop in my town, so unless having to go out of town I want to get it done locally with the repair shop specialized in Volvo. The mechanic there has 20 years of experience from the Volvo dealer, so would not think going there would make much of a difference.

Is this a familiar problem and does anyone know how to fix it? Any suggestions would be very much appreciated.

 

The T5s have two different belts - the timing belt is what drives the valve train and failure can lead to valve/piston damage. The serpentine belts refer to the accessory drive belts for the AC, alternator etc. Failure of the drive belt won't damage your valves (unless the belt snapped in such a way to interfere with the timing belt). As the T5 is an "interference engine" - meaning the open valves overlap into the piston travel space, anything that messes up valve/piston timing will cause damage. The usual cause of failure is the idler and tensioners rather than the belt itself. So to your concern, I'm a bit confused on the nature of the second incident - are you saying the serpentine belt failed or the timing belt (again the timing belt failure would cause internal damage to the engine)? Similar to the timing belt, the accessory drive belt (aka serpentine belt) also has a tensioner and idlers which can fail, plus a bad AC compressor clutch can cause problems. The simple test is to remove the drive belts and check the idlers, alternator, AC compressor to make sure they spin properly.

 

Thanks a lot for the reply. The problem is with the serpentine belt as it seems parts of the damaged belt gets into the area where the timing belt is and disrupts it and thereby causes the cylinders and calves to get damaged. I do not have enough details on how that is happening, but 2 different repair shops has told me the same. So the main issue is the serpentine belt getting damaged and breaks. It is new now, but already can see damages on it. I believe it must be alignment of the items connected to the serpentine belt. Is it possible that any of these are in an offset position? (The aircondition compressor is just replaced, but the problem existed before and after replacement.)