'06 XC70 Timing Belt Help

[jpursell]

So, I'm in the process of completing a Timing Belt, Idler Pulley, and Tensioner Pulley change, and have run into a couple issues.
1) I'm confused by the mechanical tensioner and how to properly tighten and set it. I've followed the directions in the how-to, but something doesn't seem right to me. Can someone please try to explain the pre-load and set then tighten procedure to me in a different way? should the eccentric always start in a 10 o'clock position and then move to let's say 2 o'clock and then back such that the finger is aligned properly?

2) It also seems that my cam's have moved enough that the engine won't start up. I always rotate the crankshaft 2 revs and check the marks before I start to 'feel' for any valve interference - but there's none. I believe I'm 1-2 teeth off on the cams. Any ideas?

I've replaced 2 timing belts on my old 850 with no problems. I'm hoping that the above issues could be fixed with properly tensioning the belt? Please help!! Next time, I'm definitely using a cam lock tool!

Thanks

2006 XC70
~103,000 Miles
Replaced so far:
Radiator, Condenser, Bevel Gear, Bevel Gear Collar

[howardc64]

Been awhile since I did timing belts on both my 01s. On the tensioner, assuming your engine is room temperature, you want to get the tensioner indicator "between the goal posts" (the picture with 68F on page 3 of the how-to timing belt doc). First turn the tensioner indicator counter clock wise and pass the left goal post and then turn it clock wise and centered it between the goal posts and tighten the center screw. You should be able to feel the belt getting tensioned as you rotate clock wise to center between the goal post.

Perhaps someone who's done it recently can confirm. Don't want to give you wrong directions on timing belt job.

On 1-2 tooth off. Its tricky to get the markers dead-on. Whenever I heard someone off by a tooth or 2, the car starts but throws a code. Not sure why yours don't start.

Left all my timing belt replacement notes here

http://www.freewebs.com/howardsvolvos/engine.htm

It is helpful to turn the crank slightly CW and CCW (use a socket) and see how far the cam markers move in relation to the crank's rotation. This can help guide you to make sure both cams and crank have the best alignment.

[jpursell]

Howard,
Thanks for the reply. I think I have the tensioner figured out, but I'm still stumped on the no start. I had some codes checked last week and one was the Exhaust Cam VVT Reset code. Perhaps the VVT on the Intake/Exhaust have caused the cams to move too much? My marks still seem to line up, and I've tried shifting 1 tooth on both cams and still no luck. I'm hesitant to go much further. I'm about ready to throw in the towel and have the car hauled the 1 mile to my local Volvo Dealer. Hopefully I can get them to only do it for the ~1 hour labor it would take to finish the job at this point.

[howardc64]

I had some codes checked last week and one was the Exhaust Cam VVT Reset code. Perhaps the VVT on the Intake/Exhaust have caused the cams to move too much?

Did you get this code before the timing belt job?

I read up a bunch on the CVVT when I did my timing belt job. I don't think you have to do anything other than lining up the markers. CVVT works by hydraulic pressure to change the cam's rotational angle in relation to the cam gear the timing belt rides on. I think computer decides when to change angles and activate a solenoid to let oil pressure to cause rotation. Here is some info if you are interested.

http://www.volvoclub.org.uk/tech/fue...ME7.0-CVVT.pdf
http://www.volvoclub.org.uk/tech/fue...VTfunction.pdf


I recall reading some people believe some kind of CVVT reset might necessary if the cams got moved without the belt on. But others believe same as I that you just line up the timing markers and let the internal CVVT mechanism work by itself.

Just to confirm, when you start the car, you have serpentine belt back on right? Alternator won't turn without it on. Not sure that matters though.

[jpursell]

Yup, had code last week when I took it in for an oil change. I had my local Volvo dealer do the oil change due to a CEL being on for about a week. There were no apparent issue that I could tell associated with the CEL, that's why I took it in - to hopefully have a free diagnostic and then I could fix the issue. They updated some software, and said that for the VVT Exhaust Reset, they have to first replace the solenoid, and if that doesn't rid the code, then the Hub Assy would be next. Maybe I"m just grasping at straws to make sense of my current situation, but I agree with you that the VVT mechanism should be able to compensate as long as the marks are aligned.

And, yes, the Serp belt is on. I'm now very good at removing/replacing the T-belt with the serp belt on

[cattlecar]

Turn the engine over until the crank mark(s) are aligned and the cam marks are up . You should see then whether the indicator marks are off. On your 2003 there is CVVT on both cams so either being off will set a code. You did mention it was an exhaust code that set so that should be apparent when you turn it to position.
If it is off then slacken tension until hex key hole to bolt makes 8 o'clock position. Remove belt from cam gears and move whichever is not aligned to its proper place and then re-fit belt. swing hex key CW to make the the tension indicator go past vertical and then swing it back until it is vertical and hold while tightening the bolt to lock the position.


The ECM will read the cam position sensor and change the signa to the CVVT solenoid to get the cam to the desired place, if it can. Usually the range is adequate until the engine is started cold as that is when the cam is moved the most and will run into issues of inadequate travel to get to that position. Then the DTC sets.