Installed timing belt and I think I am off by a tooth or 2 - easiest way to correct?

[T64me]

I have a 2005 S60. I recently installed a timing belt kit. The car is idling a bit rough and there is a check engine light. The code is ECM-671D Camshaft position, exhaust Low

My guess is that I will pull the timing belt cover off, check the marks on the cam gears Vs the crank and find that the exhaust cam is out of time by a tooth. If this is the case, can I simply take tension off of the belt by using an allen wrench on the tensioner, then move the exhaust cam to the correct position?

Thanks in advance for any constructive input.

[abscate]

You have to remember to pass the timing mark, then come back to it with a VVT cam, then reset the mark while keeping the hub fully rotated

If that doesn't make sense, then you need to go to timing belt replacement on VVT cars in the VRD and read up on this so you understand what is going on. With VVT the hubs move relative to the camshaft, so setting the cam hub to mark is not setting the cam to the mark, like it is on a 1998.

The benefit is you get to see all the 1998s in the rear view mirror, fussing with their IACS and their distributor caps while you listen to Italian opera.

[cn90]

- Actually, even for VVT cars, all the TB cares is its relationship between CRANK and CAM sprockets.
In other words, despite what VIDA and Volvo said in their repair book, when it is all done, as long as the TB lines up with the CRANK marks and CAM marks, you are good.

- So, yes, release the tension by first undoing the 12-mm center bolt a bit so you can adjust the tension using the 6-mm Hex key.

- Once the TB tension is loose, slide it off, rotate the CAM sprocket to marks and put the TB back on. Then don't forget to readjust tension using the 6-mm Hex key and tighten the 12-mm bolt to spec.

- I wrote a detailed DIY for my 2005 XC90 2.5T below:

viewtopic.php?f=10&t=83521

[oragex]

As was mentioned above, fully release the tensioner - make sure the 14mm bolts is loosened but not removed.

What is critical in this approach is that once the tension is removed, the belt will want to 'fall' off the crank pulley teeth. That's the biggest risk, so better have the wheel removed and the belt exposed at the bottom of the crank pulley, it will be much less stressful. A helper is great here. Watch for the cam gears do they don't rotate by themselves, that's where a helper is great if not a must, while keeping the belt pulled upwards so I doesn't fall off the crank pulley.

When the belt is back in place, before adjusting the tensioner, there should be no slack on any section of the belt.

At the end, careful check the timing alignment, the crank will be a little near the left teeth with a notch. At the cam gears, better use a mirror to watch from the front on the exhaust cam gear not from the side (I also used a thin pen to check the tiny notch on the gear is aligned with the notch in the cover.

[jonesg]

You have to remember to pass the timing mark, then come back to it with a VVT cam, then reset the mark while keeping the hub fully rotated

If that doesn't make sense, then you need to go to timing belt replacement on VVT cars in the VRD and read up on this so you understand what is going on. With VVT the hubs move relative to the camshaft, so setting the cam hub to mark is not setting the cam to the mark, like it is on a 1998.

The benefit is you get to see all the 1998s in the rear view mirror, fussing with their IACS and their distributor caps while you listen to Italian opera.

That's it, although its a lot simpler seeing it done vs reading about it.
Disregard the cam locking tool if cvvt hub is not getting removed.

[chrism]

cn90 is on track. If you didn’t loosen the hubs/sprockets, you can ignore all of forward and backward stuff. Just get all three marks on target.

[Rattnalle]

Agreed. Don't make it harder than it is. Just set the marks and it's fine. It's what Vida says to do as well, theres no fussing about mentioned there unless you start removing the gears or VVT hubs.

[jonesg]

Agreed. Don't make it harder than it is. Just set the marks and it's fine. It's what Vida says to do as well, theres no fussing about mentioned there unless you start removing the gears or VVT hubs.

If the belt is removed the spring loaded sprocket moves. If the hub is spring loaded, mine is. When i pulled the belt the sprockets went to their unsprung position.
Well he will find out one way or the other.

[dlundblad]

Agreed. Don't make it harder than it is. Just set the marks and it's fine. It's what Vida says to do as well, theres no fussing about mentioned there unless you start removing the gears or VVT hubs.

If the belt is removed the spring loaded sprocket moves. If the hub is spring loaded, mine is. When i pulled the belt the sprockets went to their unsprung position.
Well he will find out one way or the other.

Very interesting. They typically stay at 12:00 and are unsprung for me when I remove the belt.

IPD makes a nice cam gear holding tool that may help you.

[abscate]

There are both unsprung and sprung VVT hubs used on these cars

The main point is, with VVT, you cannot,in general, just take the belt off, move the hub to the mark, and replace belt - like you do on pre-VVT cars. If you get the VVT hub in place with preload, you CAN move the non-VVT hub with impunity.

You would find this when you do the test of turning the crank trying to confirm the three marks of course. When that is right, the timing is right.

Correct - there is no need/value for the cam lock tool unless you are removing hubs. There are simple ways to freeze the hubs in place for belt install with zip ties.

Cam lock tools - WATCH OUT for cheap bolts on the cam lock tool if you buy one off eBay. This can make for a really bad day

It’s good also to reiterate that the marks are NOT top dead center marks as they are sometimes incorrectly described in posts.