1998 V70 Timing Marks are Way OFF ? Was running fine.

villagepc · Post by **villagepc** » 05 Jan 2015, 14:42

Brief synopsis:
Freeze plug on water pump leaking.
Purchased all replacement parts, began disassembly.
Aligned crank pulley to the boss on the block / pump. Checked cams - they look 2 teeth off for both intake and exhaust.
Rotated crank 2x - aligned crank pulley again. Cams still do not align.
Rotated crank approximately 2 teeth clockwise - cams line up with cover.

Images show how everything is positioned when the crank pulley is aligned with the protrusion on the oil pump (boss).

Am I missing something here? Have I been driving the car around with the crank pulley being off 2 teeth? I haven't noticed a dramatic decrease in mpg (24ish) or power - and its been over 1 year since the last time the timing belt was inspected at an independent dealer (who claimed it was ok). The rest of the timing parts (tensioners / etc) were replaced 50k ago when the kevlar gates belt was installed.

How would I go about rectifying? Align the crank first, then rotate the cams to their correct positions prior to installing new belt ?

I can't imagine that the tune on the car would require both cams to be that far off - its an IPD / Custom tune, and there was no mention in the supporting paperwork advising me to advance / retard cams at all. Again - the car was driving fine - no codes / stored codes - no CEL - just a dribble of coolant from behind the tbelt cover.

Any thoughts ?

Post by **misha** » 05 Jan 2015, 15:30

Crank is ok.Cams are 2 teeth off.There is a tolerance in timing up to 3 teeth.One tooth over that is game over for the valves.

Is it a part of ipd tune..i wouldn't know.

Post by **Ozark Lee** » 05 Jan 2015, 17:24

Are you sure that the blue marks are actually at the scribed marks on the camshaft sprockets? I have seen some timing belt jobs where people just create their own arbitrary marks. I can't zoom on on your pictures to look closer.

...Lee

Post by **misha** » 05 Jan 2015, 17:45

That also felt on my mind,but i'm counting that he knows what are factory marks on cams.

Post by **erikv11** » 05 Jan 2015, 17:55

You can see from the orientation of bolts on the cam sprockets, indeed the timing is off about 2 teeth.

2 teeth is not that much, you can adjust almost 2 whole teeth (actually 1.75) just by tweaking the cam timing.

Yes OP you have it right in the question you asked: put the crank to the make, keep it there, at that time put the cams where you want them (i.e. in time, use the orientation of the bolts, or of the slots on the rear, to be sure), then put it all back together.

Post by **kahl** » 05 Jan 2015, 18:49

I would love to see the rear cam slots orientation.

villagepc · Post by **villagepc** » 05 Jan 2015, 19:48

Here's a couple more images of the actual scribed marks on the cam gears. The crank is still positioned as pictured before.

I don't have any images of the cam slots yet - I'll do that tomorrow.

Post by **dosbricks** » 05 Jan 2015, 21:59

The intake looks too close for comfort to interference. You're not backing the crank up any to align it are you? Crank alignment should be achieved in clockwise motion only.

Could this timing belt have been installed in a slack position?--that is--not taut up the right side to the intake.

villagepc · Post by **villagepc** » 05 Jan 2015, 22:29

@dosbricks

Clockwise motion only - yes. I did it twice just to confirm what I saw because I didn't believe it the first time I aligned the crank. I'll do it again prior to installing the new belt just to be triple d*mn sure though.

I still don't understand how there hasn't been a change in mpg / performance / idle... no CEL (and yes, the bulb works) - with both cams being 2 teeth off. Would have expected the O2 sensor to complain - or something - high rpm misfire, wierd vacuum readings - but no. Nothing. Had it not been for a small coolant leak, I'd still be flirting with grenading the motor being so close to interference.

I will install the new belt the "right" way, properly aligned the way it should be. I'll definitely report back to this thread as to the results (if the car runs worse / etc). I probably won't get it all the way done tomorrow since I've still have to monkey around with the water pump / tensioner / pulleys.

Post by **erikv11** » 05 Jan 2015, 22:35

villagepc wrote:... I don't have any images of the cam slots yet - I'll do that tomorrow. ...

Or just shoot a face-on pic that shows both cam sprockets, the orientation of the three bolts gives the same information.