I've seen a lot of posts about timing belt changes and I thought that I'd throw in my take on the subject. We've been selling used Volvos for 20 years and I've been through the spring-loaded tensioner on the 240/740/940, the automatic tensioner on the 850 that you had to compress in a vice and both styles of later manual tensioners, the long and short tang style.

With the newer engines (5 and 6 cylinder) with VVT, the timing belt instructions from Volvo are very confusing. The problem is that they really don't give you an explanation, just tell you to do things a certain way.

First, there's the issue of turning the engine 1/4 turn past the timing marks on the cams, then turning it back. For most people, that step doesn't make sense and runs against the idea of never turning the engine backwards. Volvo never told anyone in their instructions WHY to do this, just do it.

The reason for going 1/4 turn past, and then back, is to relax the tension on a spring-loaded VVT pulley. Instead of it snapping back when the belt comes off, it is already at the full rest position with the timing marks straight up. Of course, if you have NON spring-loaded VVT pulleys, then it really doesn't matter. In either case, had the instructions been given more clearly with a reason WHY, there wouldn't have been so much consternation over the years.

Hope this helps.

 

thanks for the share!