In general, when should one replace the timing belt? I have a 2011 C70 with 76K miles. Do you go by the years or the miles? I haven't had any issues with starting or engine noise.

 

I would replace every 10 years regardless of the mileage. And you won't have any "issues with starting or engine noise" until the belt breaks or comes off due to a bad bearing and bends all your valves. Replace all the bearings and the other belts also at the same time - don't cheap out.

A bent valve job is what ~$3500 now?

 

Thanks for the advice. Is there a way the belt can be inspected to determine its wear and need for replacement? Appreciate your response.

 

Not really - but a very old belt will show cracking lines in it - rarely is it the belt - it's usually something else that fails. The serpentine belt shreds and gets caught under the timing cover or A bearing wears and pushes the belt off - when you least expect it. The result is bent valves and a ~$3500 valve job.

 

So you would recommend changing the serpentine along with timing belt? Does the water pump need to automatically be replaced too or can that wait?"

 

Tensioner bearing, idler bearing, timing belt, serpentine belt. Some advocate water pump replacement at the same time - I don't on the first belt change. (unless there is the slightest hint/stain that it has leaked or the bearing "just does not feel right") The factory brand pumps USUALLY last at least 2 t-belt changes.

Continental makes a good kit with all timing components in it. Or buy a Volvo kit - for maybe just a few dollars more. Don't cheap out on the parts - when the cheap part fails you will not be happy. Just add a quality brand serpentine belt. (continental)

 

There is a plastic cover that you can easily remove to inspect the belt, a portion of it anyway. It's on the top of the engine to the left when facing the car. I am going to do mine soon with 60K on it. The car is a 2012 but I noticed the inservice date on paperwork I found in the glovebox says late 2011.

 

Isn't 60K a bit early to change it out?

 

No it's going on the 10 year mark which is the recommended interval based on time. I think miles is 110,000 . It's likely fine as belts last a long time these days but not worth a chance. In the olden days my girlfriend ( now my wife) had a belt go under 50k, she got a new engine under the 36 month warranty.

 

https://www.volvotechinfo.com/index....ltInterval.pdf

Here's the link to the service bulletin on timing belt intervals by engine code (can be found on the timing belt cover or decoded from the VIN). As hoonk noted, its mileage OR age, whichever comes first, and the replacement is to include the tensioner and idler pulley.