Results of measuring timing chain stretch via cam phaser adaptation.

[mtroxel]

Yeah 2 seems to be your number. I just think it's high for brand new.

It is. But then mine is still at -0.04° after 39,000 miles on the new chain. So there is some variation. Who knows? Hard to believe the chain is different. Guides?

[Theiceman]

It is. But then mine is still at -0.04° after 39,000 miles on the new chain. So there is some variation. Who knows? Hard to believe the chain is different. Guides?

yeah im thinking something wasn't changed also .. guides or badly worn sprockets maybe ? something is a miss though .. but what do we know .. we are just hacks :)

[Charles.waite]

Mine was -.7 or something after I changed mine. I think a certain amount of variance is just unavoidable when you have molded plastic components, chains, and sprockets all in the mix. Also different revisions, manufacturers, etc.

[Theiceman]

Mine was -.7 or something after I changed mine. I think a certain amount of variance is just unavoidable when you have molded plastic components, chains, and sprockets all in the mix. Also different revisions, manufacturers, etc.

i think we have some good data around all this ... what is interesting to note is people who now know these numbers but are not as intimate with what the numbers mean as we are , are telling people if it s 4.5 on a new tensioner, failure is imminent and get it done .. ( parottong what they read on the internet and want to come across as an authority.
personally from what we have seen i think:
1. old tensioner phase doesnt matter . could let go anytime, but obviously the higher the phase/ mileage the higher the risk as the tensioner is working harder.
2. New tensioner i think we are seeing now the issue is really just chain stretch , vibration, codes , chain hitting the cover, causing fragmentation etc. I have not heard of a new tensioner failure yet. Anyone else ?

new tensioner work seems to reflect +1.00 ---> -2.00 degrees

just some thoughts.

[mtroxel]

Yea the old style tensioner was a train wreck. But Audi stopped putting that on what......over 7 years ago? So almost all of those have either blown up, or been swapped out.

I think monitoring your timing phase is good practice. But its difficult to set a benchmark where everyone should hit the panic button. Since my new chain inexplicably started at life +0.46° phase adaptation, maybe I start losing sleep at -5° rather than the usual -7°?

My other thought, we are not alone. BMW told Mini Cooper owners they have lifetime chains too. That has NOT worked out that way. One web site talking about the issue:

First, Mini doesn’t really acknowledge this is a problem, they’ll hem and haw about the matter, but not acknowledge it as a pattern failure, not cool. Suffice to say if you are driving at R56 Cooper, with the N12 or N14 engine, its a matter of time, rather than if, you’ll have a timing chain problem

Sound familiar?

Read more here. http://casestudies.atlanticmotorcar....reimbursement/

[maxud]

I am back with another measuring point.
2013 Audi A4, odometer shows just under 60k miles, 2.0L CPMA engine. (I am not convinced that these are original miles)
Check engine light came on, same two codes I have seen before on 2013 Q5.
P0088 and P053F aka HPFP issues.
Here are the parameters, car was fully warmed up and idling.
audi a4 cams mod.jpg

[mtroxel]

^^^-7.76°!! Yowee!^^^

[maxud]

Dealership guideline is anything over -4 degree's we recommend a timing chain replacement, usually around 4.5-5 you will start seeing high pressure fuel faults due to the cam being out of time with the hpfp.

I have now seen two Audi's, both with over -7 degrees of adjustment, both throwing HPFP codes. I dont think your post received the attention that it deserves.

[Theiceman]

I have now seen two Audi's, both with over -7 degrees of adjustment, both throwing HPFP codes. I dont think your post received the attention that it deserves.

mainly because he was wrong and out to lunch at 4 degrees.....

-7 I might buy .. occasionally .. i was over 8 and no fuel rail issues at all

[maxud]

mainly because he was wrong and out to lunch at 4 degrees.....

-7 I might buy .. occasionally .. i was over 8 and no fuel rail issues at all

I can only comment on what I have seen with my own eyes. I have seen car have codes in the ECU and no CEL. Also no discernible driveability issues on both cars.
Is it possible the Audi tech sees a much greater quantity of cars and can generalize on a greater scale?
Yes, dealers will always try to sell services on a more conservative side, I am mainly interested in HPFP codes relationship to cam adjustment, and not what dealer recommends when.

[mtroxel]

Yes, dealers will always try to sell services on a more conservative side, I am mainly interested in HPFP codes relationship to cam adjustment, and not what dealer recommends when.

I don't have a horse in this race, so I'm just asking. What is the relationship between HPFP problems and cam phase adaptation? How would a weak HPFP drive the cam phase adjustment, or vice versa?

[old guy]

The high pressure fuel pump is cam driven to deliver a high pressure fuel pulse at a specific time. Once the cam phase gets far enough out the pulse occurs at the wrong time thus giving a code for the HPFP pressure being out of the specified range at the specified time.

[Charles.waite]

At first I was going to call BS on the HPFP relying on timing, but rethinking it, I would imagine that the n276 adjusts its duty cycle based on engine rpm and that the pump should actuate the solenoid based on the cam position, so if the cam is far enough out then that could affect fuel pressure. So yea despite seeming to be unrelated, I could see how the cam position needs to be accurate for the HPFP to time it’s solenoid actuation to the cam pulses.

[maxud]

I don't have a horse in this race, so I'm just asking. What is the relationship between HPFP problems and cam phase adaptation? How would a weak HPFP drive the cam phase adjustment, or vice versa?

The HPFP is actuated off the Camshaft lobe. So any time you are talking about Camshaft phase adjustment, it has direct effect on HPFP actuation.
At least that is my understanding of the matter. It could be that there are no issues with Pump per se, but cars' diagnostics picks up parameters out of whack and triggers the codes that I mentioned in my diagnosis.

[mtroxel]

OK but...if the cam phase adjustment is keeping the cam timing right, then the HPFP is happy???

And if I'm wrong about that, a code for fuel pressure would indicate that the power to the HPFP is at fault: not that the pump itself isn't capable of producing.

??

[Stazi]

The high pressure fuel pump is cam driven to deliver a high pressure fuel pulse at a specific time. Once the cam phase gets far enough out the pulse occurs at the wrong time thus giving a code for the HPFP pressure being out of the specified range at the specified time.

Bingo! Change that damn chain ASAP!

[maxud]

Bingo! Change that damn chain ASAP!

There is not even a question about the chain in my case. Both cars needed them asap. One car got traded in. This one will likely go through the repair.
The reason I brought up HPFP post, is that there seems to be a strong correlation here, from my statistical view, that chain stretch is also responsible for these HPFP codes.
I just looked up code setting criteria on both P0088 and P053F. Nothing in there that even hints at chain. It asks to check the component (regulator in one case and sensor in the other),
then wiring, if all else fails, replace ECU!
Yes, I know, 2 cars don't make a good statistical analysis, but thats why we have internet forums. Strength in numbers.
I will follow up on the resolution, once I hear of outcome. Its unlikely that I will get to put a chain on it, due to extended warranty.

[Charles.waite]

OK but...if the cam phase adjustment is keeping the cam timing right, then the HPFP is happy???

And if I'm wrong about that, a code for fuel pressure would indicate that the power to the HPFP is at fault: not that the pump itself isn't capable of producing.

??

Could be that the pump is working fine, but the computer is noticing whacky values for actuation time or something and it’s throwing codes. Since the HPFP is actuated off the intake cam, it’s that last rung in the ladder and thus sees the greatest effect from chain stretch.

[mtroxel]

Since the HPFP is actuated off the intake cam, it’s that last rung in the ladder and thus sees the greatest effect from chain stretch.

Thanks but I still don't get it. If the phaser is keeping the cam shaft in time, then the lobes on the back end of the cam shaft are in time too?

[old guy]

OK but...if the cam phase adjustment is keeping the cam timing right, then the HPFP is happy???

And if I'm wrong about that, a code for fuel pressure would indicate that the power to the HPFP is at fault: not that the pump itself isn't capable of producing.

??

I suspect it is because the VVT is a dynamic process. Not like the early 1.8T engine that was either on or off. The ECM is constantly monitoring and adjusting the intake cam position using the cam position sensor for reference. As the chain wears the ECM has to constantly make increasingly greater cam phase adjustments to put the cam in the expected position. So at any given time the cam phase may be out as the ECM is adjusting it back in. Once these phase adjustments get past a certain amount it can cause the HPFP pulses to be far enough out of time to cause a pressure fault. Get enough of those and you get a DTC.

[mtroxel]

Thanks old guy, but I'm having a hard time believing that the variation your describing is enough to throw a code. And I still don't understand how that variation kills the HPFP.

[old guy]

Thanks old guy, but I'm having a hard time believing that the variation your describing is enough to throw a code. And I still don't understand how that variation kills the HPFP.

I don't think it's a matter of killing the fuel pump. The pump is probably fine but the ECM thinks there is a problem with the pump because it isn't putting out the specified pressure at the specified time.

[Theiceman]

Bottom line is you almost never ever hear of anyone complaining about fuel rail pressure issues, in comparison to cam adaption timing codes. ... its usually phase adjustment numbers or some other code .. if the "dealer" thinks that above 4 will throw fuel pressure codes about 80% of B8s running around out there would have a check engine light on for a fuel pressure code...

That is not to say however they are not related, i think if you did have a fuel pressure pressure code related to this the phase adjustment would be really high , certainly not in the 4 range.

Just take our forum as a random sample ... of the hundreds ( it seems ) of people who have come on here and had to have their stretched chains replaced or noisy tensioner replace , or even come on and said there car is throwing a code ( usually P0001 P0016 etc ), how many of them said " i had a fuel rail pressure" code and nothing else..

very very very few.

[Charles.waite]

I had zero codes when my Q5 was at -7 (though it had a new pump under warranty due to a leaky seal on the n276).

[Theiceman]

I had zero codes when my Q5 was at -7 (though it had a new pump under warranty due to a leaky seal on the n276).

Me too Charles and I was over 8. Zero codes. Just a vibration at idle.

Sent from my SM-G973W using Audizine mobile app

[planekiller1]

Checked mine the other day and I'm happy with -2.55 and 92k on the clock, never had a chain done and I drive the piss out of her.

-Kurt

[Novarider]

Checked mine the other day and I'm happy with -2.55 and 92k on the clock, never had a chain done and I drive the piss out of her.

-Kurt

2012? Have you checked to see if you have the updated tensioner? If you have the old style, you can change just the tensioner since your stretch isn't bad

[mtroxel]

^^^What he said. If you have a happy chain and the original style tensioner, you have a big problem.^^^

[19birel]

For those of you who have checked this via OBDeleven, did you have to purchase additional "credits" to do it?

[Theiceman]

^^^What he said. If you have a happy chain and the original style tensioner, you have a big problem.^^^

2012? Have you checked to see if you have the updated tensioner? If you have the old style, you can change just the tensioner since your stretch isn't bad

dream crushing pricks !!!! he was sooo happy !!!

[fastboatster]

For those of you who have checked this via OBDeleven, did you have to purchase additional "credits" to do it?

No, it's one of the measurement blocks, they don't need credits to read.

[mtroxel]

dream crushing pricks !!!!

That's me!!

[19birel]

No, it's one of the measurement blocks, they don't need credits to read.

Awesome, thanks. I think I'll pick one up then assuming the dealership can't/won't check it for me when it's in for state inspection tomorrow.

[Danzzo]

Awesome, thanks. I think I'll pick one up then assuming the dealership can't/won't check it for me when it's in for state inspection tomorrow.

I Check my Camphase weekly via OBD11. i'm at 122k/miles and average out to -2.37 week over week. Lowest i've seen via obd11 was -2.22 and highest i've seen is -2.55.

[maxud]

Me too Charles and I was over 8. Zero codes. Just a vibration at idle.

Sent from my SM-G973W using Audizine mobile app

What engine code do you guys have. The only thing I have to go on is that both of the ones I saw were 2013 model year CPMA engines.

[19birel]

I Check my Camphase weekly via OBD11. i'm at 122k/miles and average out to -2.37 week over week. Lowest i've seen via obd11 was -2.22 and highest i've seen is -2.55.

That’s encouraging, what model year is your car?

I have a 2013 caeb at 73k, fingers crossed that it’s not bad


Sent from my iPhone using Tapatalk

[Charles.waite]

What engine code do you guys have. The only thing I have to go on is that both of the ones I saw were 2013 model year CPMA engines.

I had CAEB. I no longer own the car, though the new owner is a friend who is on AZ, just isn’t that active in this section.

[Frogdude]

2009 A4 with 156,000 miles. I put in a new style tensioner 2 years ago. I checked the tensioner a few weeks ago and I am on notch 8. Measured phase tonight after my commute home, so fully warmed up and it was -5.95. Not as bad as I thought it would be, but I’ll be doing the chain when I get some free time.

[mtroxel]

2009 A4 with 156,000 miles. I put in a new style tensioner 2 years ago. I checked the tensioner a few weeks ago and I am on notch 8. Measured phase tonight after my commute home, so fully warmed up and it was -5.95. Not as bad as I thought it would be, but I’ll be doing the chain when I get some free time.

Did you do a new chain when you did the tensioner 2 years ago? Doesn't seem like you should be stretched that bad unless you dive lots and lots of miles.

[Frogdude]

Did you do a new chain when you did the tensioner 2 years ago? Doesn't seem like you should be stretched that bad unless you dive lots and lots of miles.

No, at the time most of the concern was around the old style tensioner, so that was all I did. I wish this thread had been around then, it might have been the push I needed to do the chain too. It seemed too intimidating at the time and I just wanted to get that old style tensioner out of there.