Timing belt change, but advanced on vcds graph

Dreznon · May 8, 2019

BobnOH said:
"there are three dots on crankshaft sprocket. aligning the frist one with the notch on the block is impeccable."
Don't know anything about that, I've always set the crank with the flywheel pointer.

It is one in the same. I aligned it with the notch on flywheel as well. The notches automatically align if you follow the dots on crankshaft. I think it is a solution for one man doing the job, so he doesn't have to constantly move from one location of the car to the other to make sure he is in top dead center.

Dreznon · May 8, 2019

KLXD said:
If I were in your position I would:
1) Put the motor at TDC using the mark on the flywheel, not the pulley
2) loosen tensioner
3) remove the cam sprocket
4) insert the cam locking bar
5) loosen the pump sprocket bolts
6) verify the pump is pinned in the correct spot
7) position the pump sprocket with the slots centered on the bolts
8) position the belt with no slack between crank and pump
11) install the cam sprocket with no slack between pump and cam
12) install the cam bolt finger tight
13) set tensioner and torque bolt
14) verify crank position is still TDC
15) torque cam sprocket bolt using tool to hold sprocket not relying on locking bar
16) torque pump bolts
17) remove locking tools
18) rotate crank using a wrench on the crank nut NOT the cam bolt and NOT the pump bolt and verify marks

Hopefully I didn't miss anything.

It's frustrating, I know. Lots of us trying to help you avoid disaster. We're all saying pretty much the same thing or pieces of the same thing.

questions,

I can do this with starting with step one or starting with disassembling the motor again?

step one, can I do this with the harmonic balancer on?

step six, you mean lock the IP pump?

step 18, you mean rotate the motor twice, like in the regular timing belt procedure?

KLXD · May 8, 2019

Without disassembling the motor.
With the balancer on.
Yes on locking the pump.
Yes,

Vince Waldon · May 8, 2019

Dreznon said:
so I have to remove the IP sprocket?

It's the cam sprocket that needs to be free to rotate, not the IP sprocket. This means loosening the cam sprocket bolt a turn or two (using a sprocket locking tool, not the cam lock itself) and then tapping on the sprocket (or using a puller) until it breaks free of the tapered joint and can rotate independent of the camshaft

Kinda a pain, but needs to be done... otherwise timing belt slack has nowhere to go and you end up with timing issues exactly as described.

You can cheat by playing games and moving the IP sprocket back and forth by a tooth, but the cam timing will still be off (VCDS cannot show you cam timing), power will suffer, and there will be lots of white smoke. Sounds familiar, I'm thinking?

There's a great "A4 Timing Belt" pdf here that has great step-by-step instructions, with pictures at every step...might be worth tracking down if you would benefit from a more detailed explanation.

jokila · May 8, 2019

Vince Waldon said:
It's the cam sprocket that needs to be free to rotate, not the IP sprocket. This means loosening the cam sprocket bolt a turn or two (using a sprocket locking tool, not the cam lock itself) and then tapping on the sprocket (or using a puller) until it breaks free of the tapered joint and can rotate independent of the camshaft

Kinda a pain, but needs to be done... otherwise timing belt slack has nowhere to go and you end up with timing issues exactly as described.

You can cheat by playing games and moving the IP sprocket back and forth by a tooth, but the cam timing will still be off (VCDS cannot show you cam timing), power will suffer, and there will be lots of white smoke. Sounds familiar, I'm thinking?

There's a great "A4 Timing Belt" pdf here that has great step-by-step instructions, with pictures at every step...might be worth tracking down if you would benefit from a more detailed explanation.

This is incorrect advice. Both sprockets must be free to move. It is clearly outlined in the PDF and other guides.

Vince Waldon · May 8, 2019

Fair enough... the IP hub is pinned at TDC, the sprocket itself can shift slightly since the bolts are loosened a bit.

OP: here's the step-by-step proceedure: http://pics3.tdiclub.com/pdf/a4timingbelt.pdf

jettawreck · May 9, 2019

Vince Waldon said:
Fair enough... the IP hub is pinned at TDC, the sprocket itself can shift slightly since the bolts are loosened a bit.

OP: here's the step-by-step proceedure: http://pics3.tdiclub.com/pdf/a4timingbelt.pdf

Yes, linked that procedure early in the thread. If the steps are properly followed I don't know how there can be trouble afterwards except if someone prior had things (IP sprocket already "adjusted") messed up.
Hope it eventually works out ok.

BobnOH · May 9, 2019

jokila said:
This is incorrect advice. Both sprockets must be free to move. It is clearly outlined in the PDF and other guides.

Yes and no. If he has the belt on and he puts the crank at TDC and the pin lines up he may not need to loosen the IP pulley. I guess my simple method I tried to put together was confusing.
But if the belt is removed, replaced as per instructions you want both pulleys to freewheel.
And the rotate 2 times is simply Check Your Work.

jokila · May 9, 2019

To me, if you have to retension the the belt, both pulleys should be free to rotate. Otherwise, I agree.

KLXD · May 9, 2019

Yeah the bolts need to be loose. Otherwise there would be some amount of slack between the pump and crank. Maybe a little, maybe a lot.

Same rationale as why the pin must be removed on the AHU before tensioning.

BobnOH · May 9, 2019

Yes, best practice, loosen both pulleys. I was making a lot of assumptions. From what I remember the tension all applies at the cam side, straight shot from IP to crank, so if it's installed and tensioned....blahblahblah............... Bad assumption, better safe than sorry.

Dreznon · May 9, 2019

Thanks Everyone, I am going to give it a go this weekend and post back how it goes.

Just to recap:

spin the motor to TDC,

Lock IP,

loosen the tensioner,

Loosen cam sprocket,

remove belt at cam and IP

spin cam 1 tooth. reassemble and try it out. If still advanced too far to graph, then repeat until in the graph on vcds.

gotchya.

Dreznon · May 9, 2019

I hope the belt doesn't fall off somewhere underneath where I cannot see.

jettawreck · May 10, 2019

Dreznon said:
Thanks Everyone, I am going to give it a go this weekend and post back how it goes.
Just to recap:
spin the motor to TDC,
Lock IP,
loosen the tensioner,
Loosen cam sprocket,
remove belt at cam and IP
spin cam 1 tooth. reassemble and try it out. If still advanced too far to graph, then repeat until in the graph on vcds.
gotchya.

Not exactly. Slow down and look at the steps KLXD laid out and/or the article closely. Done properly there shouldn't be any "repeats".

Dreznon · May 10, 2019

rodger dodger

BobnOH · May 10, 2019

Yea, no.
Rotate to TDC
Lock crank
de-tension
remove belt
Loosen both pulleys, break cam pulley loose

Lock cam
Pin IP
Install belt
tension
tighten pulleys

remove locks/pin
check your work (rotate a couple times, check crank, cam, IP aligned)
fine tune

Dreznon · May 11, 2019

Hey guys,

I completed it and was excited because It was difficult to find the sweet spot to start it and I know that is how it supposed to be.

It started up anywhere from just retarted of center bolts of IP all the way back to full retarted as it can go.

VCDS still shows start of injection at 255 and timing at 255. I believe I need to take it apart again and this time not worry about anything but moving the IP pulley however far it needs to go to get to 65, like my initial thought.

I may just have this eurotuner shop do it. They said a few hundred dollars and this is seen almost all the time. I just figured you guys would've just let me know on here. I guess if the information is on here then how are mechanics ever going to get paid if people know how to do it themselves.

High hopes and cheers.

Dreznon · Oct 13, 2019

Update on this thread.

The IP pump was faulty although it was a rebuilt one. I was sent a new one and it worked. sort of...

check out my other threads to understand more. Especially the one entitled, "Does the fuel stay in the line to the IP?"

Timing belt change, but advanced on vcds graph

Dreznon

Well-known member

Dreznon

Well-known member

KLXD

Top Post Dawg

Vince Waldon

Top Post Dawg

jokila

Vendor

Vince Waldon

Top Post Dawg

jettawreck

Top Post Dawg

BobnOH

not-a-mechanic

jokila

Vendor

KLXD

Top Post Dawg

BobnOH

not-a-mechanic

Dreznon

Well-known member

Dreznon

Well-known member

jettawreck

Top Post Dawg

Dreznon

Well-known member

BobnOH

not-a-mechanic

Dreznon

Well-known member

Dreznon

Well-known member