Camshaft phase position range?

[kruat]

https://www.audizine.com/gallery/data/500/thumbs/20200402_164548.jpg (https://www.audizine.com/gallery/showphoto.php?photo=95633&title=20200402-164548&cat=500)

I'm getting ready to do a complete timing belt job on my RS. Decided to run some logs before hand. I noticed my phase position seemed to have a large variance between the two banks. Should I be alarmed? No CEL's, car seems to run great.

I wasn't planning on replacing the camshaft tensioner pads yet, as both showed -.5 at idle, and under load both showed around 20. I didn't want to have to pull each valve cover. I just wanted to do a simple timing belt job. But after looking at the log, I'm wondering if one or both of my banks were not timed correctly the last time it was done, and if it would be smart to check the actual cam timing per bank.

What do you guys think? Car only has 60K, and the last timing belt job was done at 30k, but that was roughly 7 years ago. No other issue's as all, no CEL's and performs great.

[nubcake]

91 and 92 will always show 0-20, after cam adaptation had occured.
-10 in 93 sounds pretty bad, but it will run & drive with no CEL.
Bank2 is driver's side FYI.

Doubt it's about chains (being a tooth off is like 20deg off, IIRC. And usually manifests in bent valves), but you can take one valve cover off to verify.
I'd say do a normal timing belt job & recheck values after.

[kruat]

Cool, think its belt stretch or maybe bank two was not correctly lined up? Like the cam lock bar wasn't used?


Also, what order does one need to put the new belt on in?

[GreggPDX]

Yeah, that range is not horrible, a bit out of spec, but for an older belt, probably not surprising. When I recently did mine, I religiously followed the instructions for setting the cam timing, and used all the proper tools, but still ended up with one of them out of spec. I think it was like -2, -7. I actually very carefully loosened the cam bolts and slightly adjusted the position of the sprockets until I got them both at 0. I had the front clip off, but left the oil cooler attached so I could run the motor for short periods (no coolant). It took a few tries to get them perfect, but wasn't that difficult. I used a sharpie to mark the exact position of the cam relative to the sprocket, then move them just slightly to see how much difference it made. It does not take much!

[nubcake]

We did the same (as Gregg) to my car over here.
Factory procedure still left them out of spec pretty badly.

I didn't get the question about order. Doesn't really matter, as long the factory procedure is met (lock crank & cams, etc).

[kruat]

Oh, I had heard there was an order when putting the belt back on. Now, I've done numerous timings belts on other cars, this was the first I had heard of an order.

Cool, I'll drive on with just doing the belt tomorrow, then log it again.

Are you guys popping the cam gear off with the belt in place, then making a small adjustment?

[nubcake]

Are you guys popping the cam gear off with the belt in place, then making a small adjustment?

If both banks are off in one direction - unlock the crank & move it slightly, while having cams locked by a bar.
If only one cam is off - use the bar to hold (and slightly turn) said cam. Gear(s) will need to be loosened & popped off for both adjustments.

Hope that made sense.

I'd be aiming for +/-4 each (and between banks). Having them dead centered is cool, but gives no real benefit.

[kruat]

Sweet, thanks a lot.

[kruat]

Well, got the timing belt done. Started, check block 93 and have -7 and -10. So better, but not perfect. I did not make any adjustments like you guys mentioned.

But, does not matter much, as it has to come all back off again, I think I have a bad water pump gasket, or the thermo gasket didn't sit right. I have coolant streaming down the front of the motor.

[nubcake]

Leave cams locked & turn the crank slightly. Bring it to like 0 and -3, should be good enough.
Bummer on the leak.

[kruat]

Ok, should I rotate clockwise or counter?

[nubcake]

Frankly, I don't recall. :)
Off the top of my head (thinking out loud) - engine rotates clockwise (looking at it from the front).
"-" means it's overly advanced (opens too early), so you want to time the crank earlier. Meaning, counterclockwise, looking from the front.

But better get someone else to confirm.
Or move it very slightly either direction, clear DTCs (!), and re-check 93, noting which direction the values shifted.
Clearing DTCs also resets adaptations. If you don't, it might stay where it was, despite being moved. Verify by looking at 91 and 92.

[kruat]

Ok makes sense. I was just hoping to not pull it apart for a third time if I went the wrong direction.

[kruat]

Well I've finally got a day to get back on the RS. I'll report back later with what I figure out. I'm thinking, since my cam phase is - or retarded, then I'll move the crank ever so slightly counter clockwise to account for the advanced timing, like NubCake mentioned.


Side note, my Milltek exhaust and wheels arrive today as well, even more reason for me to stay in the shop all day. ��

[GreggPDX]

Well I've finally got a day to get back on the RS. I'll report back later with what I figure out. I'm thinking, since my cam phase is - or retarded, then I'll move the crank ever so slightly counter clockwise to account for the advanced timing, like NubCake mentioned.


Side note, my Milltek exhaust and wheels arrive today as well, even more reason for me to stay in the shop all day. ��

Pics or it didn't happen! :)

[Muggy]

Niiiice....I love the Milltek!

Also following to see how this works out for you... :thumb:

[kruat]

Alright, she's back together again. Turns out, when you don't put the thermostat gasket on the correct side of the thermostat, it'll leak...:doh:


And as far as the timing, I did mess with it a bit, and got it within 3 degrees of each other. So, better but not perfect. I've got -2 on one bank and -5 on the other. I just didn't feel comfortable moving it anyone. Nor, do I wanna take it apart again.