2005 XC70 Timing belt - timing marks?

[jonesg]

the last time I swapped a belt I locked the cam sprockets, released the tensioner and changed it out.
engine doesn't even need to be set up in time.
Unless you're removing the cam sprockets to do the seals all the drama can be eliminated.

[iamhives]

Thanks for all of the information. I'm now in information overload. In answer to the question, the engine is a B5254T2.

cn90 - thanks for all of that definitive information on VVT, cam seals etc. Its helpful to understand how the VVT works in concept and if I very do attempt cam seals etc it will be useful. Unfortunately, all of that VVT stuff is beyond my capability/desire right now. I don't need to (well I may need to but won't right now) remove/replace cam sprockets/cam seals and since the car seems to run OK with no codes and just needs a water pump/idler/tensioner/belt I want to do the minimum necessary.

So jonesg's post seems to indicate that this can be done ignoring all of the VVT complications. So since when my crank gear marks are aligned down below my cam sprocket marks are not even close to the timing cover grooves, can I basically just ignore them and make by own marks on cam sprockets etc to ensure relative positions? Do I need to worry which of the two positions where crank marks align since I can't tell which is position is which based on the cam sprocket marks being so far off? Or can I just randomly pick one of the two cranks mark alignment positions and go from there?

Is the cam sprocket locking 100% necessary or will the VVT hubs/sprockets move (due to their nature) once the belt is removed. I did the timing belt on a regular (non turbo 2006 V70) without any locking tool - maybe this was because it doesn't have the VVT complication?

Sorry for all of this back and forth on topics which I suspect are common and repetitive for those on here who are more capable than I.

[erikv11]

It takes two full rotations of the crank for one full rotation of the cam sprockets. Are you just 180˚ out of phase? Try one more full rotation of the crank and see if the cams come in. Or is that what you're referring to above re the two crank mark alignment positions?

Yes you can make your own marks and just use those, even when you have the factory marks it is a good plan to do that. Before you take it apart, make extra marks on everything including the VVT. These marks can add to or completely replace the factory marks. It wouldn't matter which of the two full crank revolutions you choose, as long as the cam marks are the same before and after and the VVT hubs are properly loaded.

jonesg doesn't exactly mean "engine doesn't even need to be set up in time" as stated, he really means "crank does not even need to be on the mark." The engine absolutely needs to be in time and stay that way. Keep in mind of course that the potential issue of not using the crank mark is, if something goes awry, e.g. if a sprocket slips even though it wasn't supposed to, could be a big hassle to get it all back together again. The beauty of having the crank on the mark is you can safely move the cams to where they need to be, without obstruction. You can probably lock the cams with a bunch of heavy zip tis and do it like he mentioned, but with some risk. Maybe a combo approach of putting the crank on the mark, but then lock the bejeezus out of the cams and do it that way.

I haven't done enough P2 timing jobs yet to remember enough to answer your last question.

Back and forth is worth it on timing questions!

[iamhives]

Thanks ericv11

Yes, I was referring to the 180 degree out of phase as the two positions when the crank is rotated once. In the two positions (seperated by 1 crank turn) when the crank marks are aligned my factory cam sprocket marks are nowhere near the cam cover grooves and are misaligned from each other. I do know from my records that the cam seals were done about 90k miles ago so my guess is whoever did it was lazy and didn't align the cam sprocket marks to the cover? So that requires me to make by own marks and ignore the factory cam sprocket marks.

I bought the rear cam locking tool from Amazon so assuming I can get that on that should ensure the cams don't move.

Regarding the VVTs and the cam sprockets. I don't 100% understand their operation but am going to assume (since the engine runs OK) that the timing is right so just need to replicate what is there now. When I take the belt off, will the VVT/cam sprockets move even witht he rear cam locking tool? I hear they are spring loaded which suggests they will. And I then read about turning the crank 1/4 turn past alignment and then CCW back and the need to correctly 'load' the VVT units. Can someone describe what this means and what needs to be done to the VVT/cam sprockets when the rear cam lock bar/tool is installed and I remove/reinstall the timing belt

Thanks ! As you can tell I'm a little nervous about trashing the engine and this is my most adventurous DIY work on the car so far!

[jonesg]

If you think its 180 out, rotate the crank and look again.
if its still not lined up then thats just how it is, it doesn't mean the cams aren't in time
The cam shaft to sprockets are not keyed, they are free spinning unless torqued down.
If you're wondering how it got the way it is ?, I think I read they can come like that from volvo.
i'll see if i can find that info again.

if you decide to make the timing marks on the front cams line up you'll need to lock the rear of the camshafts with a rear camshaft locking tool, it takes you a lot deeper into a simple job. Right now the engine runs good, you'll gain nothing going down the rabbit hole.

found it.

"I personally prefer the Euro version of the timing install it's way easier
NONE OF those cam gear MARKS MATTER !!
Factory doesn't line anything up using those marks ( they are designed for a timing belt verification and reinstall of the timing belt after ) "

that verification only matters if the cam sprockets moved, if they are locked you can just swap the belt and fuhgetaboutit.

i suspect you aren't seeing the vvt timing marks, theres couple of marks, only 1 is correct.
this video shows the 2 marks. naturally, with volvo, the correct mark is not obvious.

[iamhives]

I'm 99% sure I'm looking at the right cam sprocket marks. In any case none of the cam sprocket marks correct or otherwise align with the timing cover grooves when the crank gear marks are aligned so I'm jst going to ignore than and make my own marks.

I'm just going to go ahead and use the rear cam lock tool and replace the belt without realigning the VVT/cam sprockets. Leave that problem to the next owner or/when if I ever need to do the cam seals! Car has 175k and had timing belt and seals done at 100k. If I get another 25k out of it I suspect that will be enough until my son (who just graduated) is in a position to get a replacement

[iamhives]

Just wanted to close this thread out. I successfully changed the timing belt, water pump, idler and tensioner with the help of the suggestions and information from this forum. I did it with my son so it was also a good bonding/learning experience for him. I did use the rear cam lock tool as suggested. In retrospect, not 100% sure it was necessary but better to be safe than sorry. I didn't remove the harmonic balancer - with care there is just enough room to get the belt around it and onto the crank pulley. I guess whoever did the timing belt and cam seals previously didn't bother to align the marks on the cam sprockets which was the main source of my questions. Now on to front suspension work!

[cn90]

For those reading this thread in the future...

For routine TIming Belt, WP job in P2 cars, NO need to lock the rear of cam shafts, as long as you don't disturb them.

Info is in the link I posted.

[erikv11]

If you're new to the job, consider that basically every shop (including the dealer) requires their techs to use them. It's easy to see why: cam tools are a cheap and easy way to be sure you don't mess up.

But if you've been around the block or like to think you have or there are other circumstances, then of course you can give the cam tools a miss and it can work out just fine. If as stated you can ensure by some other means ensure the cams don't move, then you'll probably be happy you didn't buy (or borrow) them and bother to put them on.

As with any repair procedure, no blanket recommendation ("always use them" or "never use them") fits every case, in the end it's up to personal choice/preference/decision.

[cn90]

O.P.,

The link for routine TB, WP, tensioner job is inside that link I posted above.
NO need for cam-locking tool.
You only need cam-locking tool if you replace the VVT Hubs +/- Front cam seals.

It was written for my 2005 XC90 2.5T.

I will link it again:

DIY: 2005 Volvo XC90 2.5T 110K miles: Timing Belt, Water Pump, Serpentine Belt
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