1998 V70XC - Crankshaft/camshaft timing confusion and questions

[VolvoOwl98]

Straight to the point, trying to align timing to work on some oil-related things. Spent over an hour last night locating and aligning what I believed to be the marker on the crankshaft timing gear with the mark on the oil pump. Doing so resulted in this for the camshaft sprockets:

Then today I got the rear camshaft hardware out of the way, revealing this to be the timing according to the cam notches:

My current questions are:
a) Can the crankshaft be turned back a bit to align the camshaft notches with the seam of the head as discussed here: viewtopic.php?t=53620. If so do I have to put back on the distributor rotor and cam position sensor, or is it fine to adjust their orientation on the floor to keep them matched up?
b) Can the crank nut be put back on to rotate the crankshaft after removing the harmonic balancer to get a better look at the crank gear?





Edit: Last night when I saw the tiny notch come around, I rotated the crankshaft back 2 teeth marks and forward one to align the mark and keep the belt under forward tension. Here's the photos I tried to get when I did so, but it's hard to see in the photos.

[abscate]

Your crank looks ok but the -1998 cam marks don’t point straight up when in time.

Those cam slots in the rear of the cam are way off , confirming cams are wrong. They both should be horizontal with one space up and one down.

I’ll try to find pictures..see here viewtopic.php?t=52960

[VolvoOwl98]

...but the -1998 cam marks don’t point straight up when in time.

I was confused about this, since in VIDA and looking around I saw mentions of both positions for the notches on the timing sprockets

Screenshot 2026-08-22 231131.png (128.86 KiB) Viewed 869 times

Having looked at Saskia's timing cover again, something I somehow missed before is an area where the plastic section that hangs down and has the notches for the camshaft gears to point in at each other is missing, and that spot is pretty smooth. I think looking in VIDA I somehow confused myself about which to use.

(Of vehicle history note, someone marked their own separate marks on the crank gear, cam sprockets, and one at the straight upright position on the timing cover with a black paint pen... so I don't even know what the status on them is, other than that she somehow ran without an interference engine going kaboom

I know to align the camshafts accurately when the sprockets are in question is to use their position at the rear, where Ozark Lee discusses in this thread here: viewtopic.php?t=53620

To be absolutely certain of crank timing I'm picking up the counterhold tool (p/n: Volvo 999 5433) from IPD on Monday (how I didn't have that before is a different story), am going to remove the harmonic balancer/vibration damper, get a much closer and better look at the crankshaft gear, and once verifying it's alignment (or adjusting if necessary) will move to dealing with the cams. Do I need to worry about accidentally flipping the cams 180 degrees, which I guess really is a question of how can I verify that nothing will go BONK when firing up?

Those cam slots in the rear of the cam are way off , confirming cams are wrong. They both should be horizontal with one space up and one down.

To above question, does this mean I can take the sprockets off and manually spin the cams to be aligned with the head seam without repercussion, so long as I rotate them both in the same direction? (I.e. the short distance clockwise or the long distance counterclockwise)

If I sound grouchy, it’s not intended at anyone. I very much appreciate and am thankful for any and all help. Just pretty stressed about this with having to now be working on a very tight deadline. Need to be able to drive Saskia ASAP

[erikv11]

For a 98, the marks are like Abscate described, although I trust Lee's post about the 5254. VIDA is great but is known to be riddled with errors.

Regardless, To fix the timing:
- leave the crank on the mark. Make sure you have it right. I believe you when you say you saw the mark but I didn't see it in your pic. The crank MIUST be on the mark.
- The crank MIUST be on the mark.
- Also, the crank MIUST be on the mark.
- Now you are free to spin the cams however you want. No need to remove the sprockets. I would not touch the cam sprocket bolts.
- align the horizontal rear cam slots
- check the marks on the sprockets, hopefully they are now like Abscate said but in truth it doesn't matter. the crank mark and the horizontal cam slots (make sure you get the over/under right on the slots!) are the sole determinantnts of timing. The cam marks are just to make it easier to find correct timing.
- if the marks on the sprockets are off you could move the sprockets but better is to leave them alone and put your own marks down, that you know ID correct timing.

The timing belt must be off to do this. Unclear to me from your post is if/when the timing belt came off, why you're adjusting timing, if the car seems to run fine already, etc.

[VolvoOwl98]

Unclear to me from your post is if/when the timing belt came off, why you're adjusting timing, if the car seems to run fine already, etc.

The timing belt is still on and hasn’t come off in the year that I’ve owned the car. I’m changing out the front cam seals, front crankshaft seal, and oil pump seals. My car already runs alright, but I am wondering if the timing is currently moved in such a way that it’s being a hinderance (such as fuel in the fuel economy department).

- check the marks on the sprockets, hopefully they are now like Abscate said but in truth it doesn't matter. the crank mark and the horizontal cam slots (make sure you get the over/under right on the slots!) are the sole determinantnts of timing. The cam marks are just to make it easier to find correct timing.
- if the marks on the sprockets are off you could move the sprockets but better is to leave them alone and put your own marks down, that you know ID correct timing.

Since I have to take the sprockets off anyways for the seal replacement I think I’ll go ahead and try to align the factory timing marks as best as I can.


So to make sure I get this right, both the camshaft slots at the rear are off-centered, the intake camshaft rear slot has to be above the head/cam cover seal line, and the exhaust camshaft rear slot has to be below the head/cam cover seal line. (That makes sense then, that would prevent the cams from being flipped 180 degrees to where both the intake and exhaust valves would be open at the same time.)

So to verify that nothing makes contact I assume once cam timing is corrected, seals are replaced, and the belt goes back on, manually rotating the crank by hand (with spark plugs removed so there isn’t compression) and listening/feeling for contact is a viable double-check?

And yes I will make sure that the crank is on the mark, that’s why I’ll quadruple check its position by taking off the harmonic balancer, so I can have an up-close look at the marks

[erikv11]

This doesn't fully check out: since you've been driving the car fine, If the crank is truly on the mark then the cam slots should be nearly parallel to the seam in the cam cover i.e. the plane of the engine block. Timing can't be off by more than a few teeth before things get catastrophic.

I suspect you don't have the crank mark ID'ed correctly.

With the belt on, rotate the whole thing until the cam slots are where they should be. Then, look for the crank mark, it should be there or very close to where it should be.

Yes you have it right regarding above/below for intake/exhaust cam.

[erikv11]

Note also the orientation of the triangle formed by the cam sprocket bolts, when the engine is in time, in abscate's photo. These triangles match up with what's happening with the rear slots.

[abscate]

Remembe the engine is angled slightly, so use the seam on the cylinder head cover to parallel the rear cam slots, not the ground.

I think you are missing a chunk of your timing belt cover

[VolvoOwl98]

Thank you all for your input! Adjusted and locked the cams to be level with the seam of the block (with the proper above and below), and I think the crankshaft gear mark (of the several I seem to have identified, hopefully right this time) is lined up with the oil pump mark. But because I'm not going to do timing stuff on an "I think," working to pull the harmonic balancer off... oi is the nut on there tightly

Oh, and the cam marks do both point towards the middle of the top cam cover at about a 45 degree angle, I am missing the plastic piece that's used for alignment



Update: borrowed an impact driver from a family friend which made quick work of the nut. Harmonic balancer came off with some WD-40 and a couple solid hits with a rubber mallet, targeted towards the inner metal of the balancer

[erikv11]

Sounds like you're rolling along!