Broken timing belt

jtklein · Post by **jtklein** » 23 May 2016, 05:55

I have 2003 V70 non-turbo. The timing belt broke and I am in the process of changing it out. A couple of questions. 1) It broke while at idle, but I would suspect that I still bent some valves. Should I replace the belt and determine what valves are bent, or tear it down now while the belt is off? Will bent valves be obvious or just slightly bent? 2) I cannot find the crank timing marks. I am shining a super bright halogen light on it and I see no indentations. I even had my teenage son looking for it too, but no luck. Could there be other markings on my car rather than the indentions? Is there some other markings or something else that would lead to them or narrow down where they may be? Any help would be much appreciated. Thank you in advance.

Post by **abscate** » 23 May 2016, 05:59

They are hard to see. Clean off the pulley and work the pulley around slowly. You will have to be turning both the cams and the crank pulley to work it around.

Read up on how to put a belt on a car with variable valve timing (CVVT)... It's a bit more complicated than the earlier cars.

You basically can count on bent valves if the TB breaks. Test compression after you practice putting the belt on to guide as to which valves are bent, if any.

Rooting for you!!

Post by **oragex** » 23 May 2016, 18:41

S60 timing belt marks

Post by **MadeInJapan** » 23 May 2016, 19:20

Markings are hard to see...better to drag a finger nail on the cam gears and feel them. Btw, no way around bent valves- you have some, of course you won't know which for sure until you tear into it.

Post by **abscate** » 24 May 2016, 04:48

Compression test with a new belt will tell you exactly which ones to replace. Much better than inspection after the fact, and cheaper than replacing every valve ...10 exhaust valves at $50 each?

jtklein · Post by **jtklein** » 24 May 2016, 06:37

Thank you all for your replies. I truly appreciate it. My thought was to put the belt on and do a compression test and that seems to be the consensus. Thanks again for your replies.

Post by **MadeInJapan** » 24 May 2016, 20:20

Sure but be aware that if one cylinder is showing low numbers, you still don't know which ones- the intake or exhaust valves. There are 4 in each chamber. Better to buy more than you need and send back what you don't use. You still won't know exactly the damage until you tear into it. Sorry abscate...if a cylinder hold tight through both compression and decompression, then that one doesn't need any. It only takes one valve in one cylinder to give you low numbers. That said, my experience has been that when valves are bent, it's usually the exhaust but that can be different in many instances and it could be all of them too... but usually they will go in pairs- 1- exhaust first- I've seen where all 10 exhaust are bent and none of the intake...It's weird and different scenarios for different instances. In my son's and my car's case, his only had exhaust valves that were bent...mine- all of them.