"The water pump broke and threw the timing belt off". Does this make sense? I am looking at a for sale ad for this 2006 XC70. I am unfamiliar with these cars [all my Volvos are much older]. Could a water pump failure affect the timing belt?

This happened on my C70. My other car is a 2007 xc70 and I really like it. For $500 I would consider buying it if I knew a mechanic who would replace the valves for a reasonable amount.

Hello Philip,

Mikebox tells me that the camshaft and water pump are driven by the same toothed belt. That might mean that the crankshaft belt is a separate animal and that the damage might be less. Perhaps you can confirm that with your experience with the C70.

If the damage is limited to bent valves it might be worth buying and fixing.

I do know a machinist who has done work for me on heads. I could call him and get an estimate.

Thanks for your input.

Bob aka muskox37

As Chris said, there is one belt from the crankshaft to the cams and water pump. When the timing goes off from this damaged belt, the valves are bent.

Looks like I should keep my money in my pocket.

“Does this make sense?”
Absolutely! Personally, I would steer clear of that car. It is likely to have bent valves like Phillip’s car. It is an interference engine. If the timing belt slips or breaks the valves can be damaged. Most of the RWD cars are non-interference engines.
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Will I buy another Volvo??? We'll see....

Hello jwalker,

I think I will take your advice and stay clear. She only wants five hundred for it but if the timing belt was affected it could be very serious. I know the water pump runs off its own belt in the older cars but I am just not familiar with the AWD cars.

Thanks for your input

Bob aka muskox37

water pump is driven off the same toothed belt that drives the cams; it is situated inside the timing cover. It is usually suggested to replace it at every other timing belt replacement/service

Hello mikebox,

So from what I can glean from your commentary, the water pump and the camshaft are driven by the same belt.

That would indicate that the timing belt that runs around the crankshaft is another belt altogether. If this belt is still doing its job, then the damage would be limited to the camshaft driven valves. Am I right so far?

I have been reading that some of these cars come with a chain instead of a belt but I take it from what you say that this car will be equipped with a belt.

Thank you for your input.

Bob aka muskox37

There is a single toothed timing belt that connects the crank, cams, idler pulley, tensioner, AND water pump. If the water pump bearing goes bad it can cause more slack in the timing belt than the tensioner can make up for, or it can cause the belt to track way out of line, or both. The result is piston/valve contact.

Given the monetary value of a car that age, if you have to pay a mechanic the repair the engine, then the car's current value is next to zero. If you can dig in and repair it yourself then the car might be worth a bit more than zero. Now if the car is loaded with good parts that you need on another one then that's a different story.

my AC belt broke and the remnants got tangled up in the timing belt which messed up the timing which bent the valves.

Thank you Philip.

This is probably what happened to the car in question. I was just wondering if she was confusing the timing belt with the accessories belt. Probably pretty serious damage.

Bob aka muskox37