Help with timing belt on CAGA engine

Discussion in 'Audi TDI forums' started by aoleks, Aug 26, 2016.

  1. aoleks

    aoleks New Member

    Joined:
    Aug 26, 2016
    Messages:
    12
    Car:
    Audi A4 B8 2008 2.0 TDI CR
    Location:
    London, UK
    Hi all,

    I'm new around here. I would need some help with a timing belt change on my A4 (B8 2.0 TDI CR). For the record, I'm no mechanic, but I do all the maintenance on my car and motorcycle and never had any issues. Today however, I had to stop...

    I saw your video on how to change the timing belt, I have the official Audi workshop manual and there's also a PDF that describes the procedure for this engine model.

    What I read is that I need to turn the crankshaft to TDC (did that, all ok), lock it with the special tool (did that, all ok) and then lock the camshaft and high pressure pump with the M6 pins. When my crankshaft is at TDC, the pins don't go in the holes, they're a bit off (roughly 1mm each). The video mentions that sometimes, the holes are a bit off due to belt wear, but what happens if I unscrew the camshaft and high pressure pump without the bolts in?

    It doesn't make sense to me that I would be able to insert them at a later point, because the loose sprockets do not turn the cam and pump. Also, if I were to turn them manually after taking off the belt, I'm afraid I might ruin the timing.

    My questions are:

    1. Why aren't the holes aligned when engine is at TDC? Even the TDC window on camshaft is at around 11 when the pin can be fitted.

    2. Am I right when I say that once I align the crankshaft, if I then manually move the camshaft and high pressure pump to accept the pin, everything will be aligned? Or isn't this the way it works?

    3. Is there any way to reset the timing, revert it to factory settings in case anything goes wrong?

    4. How do I remove the serpentine belt tensioner on this model??? It's attached from the back, but I don't see any bolt!

    Thanks a million, all help is appreciated.
     
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  2. chittychittybangbang

    chittychittybangbang Administrator

    Joined:
    May 23, 2007
    Messages:
    23,862
    Car:
    2006 Jetta TDI
    Location:
    CT
    Nothing will happen if you unscrew them, just adjust them a tiny hair later so you get the pins in. You won't ruin the timing, that's set by the TB belt which you're about to do.

    1. cause wear.
    2. yes.
    3. just don't move anything much and you'll be fine. but to do what you say you'd have to remove the cam and put crank back to TDC, then cam to TDC. no reason for this.
    4. there should be a bolt somewhere or other attachment, take a pic and it would help describe it.
     
  3. aoleks

    aoleks New Member

    Joined:
    Aug 26, 2016
    Messages:
    12
    Car:
    Audi A4 B8 2008 2.0 TDI CR
    Location:
    London, UK
    Hi!

    Thanks a lot for the quick response. I only regret not doing it then, but I didn't want to mess things up. Now I have to talk half the car apart again... :deadhorse.

    Quick questions:

    1. I can imagine belt wear causing the misalignment. If I were to take the belt off, would the camshaft move on its own? If not, how do I adjust it to be able to fit the pins?

    2. What about the pump? According to the manual, it can be off by a bit without affecting engine operation, but how do I lock it in place if it doesn't align with the other two? Can I just adjust it manually (same as camshaft)?

    Thanks
     
  4. Keithuk

    Keithuk Super Moderator

    Joined:
    Aug 29, 2010
    Messages:
    6,880
    Car:
    2010 Golf GTD (170) CBBB
    Location:
    Stoke on Trent, England
    My TDI Timing Belts App covers your

    A4 2.0D TDI CR 2007-11
    Engine code: CAGA, CAGB, CAGC, CAHA, CAHB

    If you want more info with the official Audi workshop manual and PDF.
     
  5. aoleks

    aoleks New Member

    Joined:
    Aug 26, 2016
    Messages:
    12
    Car:
    Audi A4 B8 2008 2.0 TDI CR
    Location:
    London, UK
    Hi Keith,

    Thanks, downloaded and installed, works like a charm.

    I guess the answers to my questions are that 1.) I can lock the camshaft sprocket into place with the pin and then loosen the three bolts holding it tight. If I then align the crankshaft, the sprocket will move, not the cam itself. Also, 2.) the high pressure pump can be moved with a screwdriver once the belt is off. This means all three points will be aligned. All I'm left to do is count the number of teeth before taking the belt off, to make sure I position the new one in the same way and I should be ok.
     
  6. Ol'Rattler

    Ol'Rattler Well-Known Member

    Joined:
    Apr 24, 2011
    Messages:
    783
    Car:
    06 TDI Jetta
    Location:
    Marysvile, WA.
    Absolutely no reason to count the teeth. That is what "Mark and Pray" imbeciles do.The three indexing pins are the Holy Grail of your timing.
    • What you do is with the three pins installed, Install your new belt.
    • Remove the cam and HP pins removed and the three bolts on the cam and tensioner loose, tension the belt.
    • Tighten the cam and HP bolts.
    • Turn two turns until the crank pin is again a slip fit.
    • Re-tension the belt if the tension is is off.
    • Adjust the cam and the HP until their pins are as slip fit.
    • Remove the pins and turn the crank two more turns until the crank pin is a slip fit.
    • Your belt tension should come back as correct and your cam and HP pins should be a slip fit.
    • Remove all of your timing tools, recheck all of your torques and you are done.
    An extremely accurate and easy procedure to do if you get your brain around it first.
     
    Last edited: Sep 23, 2016
    audi1z likes this.
  7. aoleks

    aoleks New Member

    Joined:
    Aug 26, 2016
    Messages:
    12
    Car:
    Audi A4 B8 2008 2.0 TDI CR
    Location:
    London, UK
    Alright, just a quick update :)

    I changed my timing belt two days ago, along with all the pulleys, the tensioner and the water pump. I locked the camshaft into place first, then I had to turn the crankshaft back a bit to be able to lock it as well. The high pressure pump was then aligned, but I could've moved it with a screwdriver if I had to. Once everything was locked in place, I released the tension and removed the old belt. Replaced pulleys and water pump and later installed the tensioner. Once everything was in place, I installed the belt according to the manual, making sure it's a tight fit on the HP side of the engine, leaving some slack between cam and crankshaft. Tensioned the belt with the needle perfectly in the middle, tightened all the bolts to the required torque and voila, that's it. Took about 20 minutes and really, if you pay a bit of attention, there's nothing that can go wrong.

    Put everything back together and started the engine. Starts immediately, runs like a charm and revs properly.

    The only thing I forgot to do is to screw back the left side of the intercooler hose, which popped out during driving. I heard a depressurising sound and lost power instantly, but didn't know what happened. I went home in limp mode and took the bumper off just to see the hose loose. I've put it back in place and now things are back to normal.

    Just saved £599 at my local Audi :)

    Thanks for all the help
     
    Mar4ix and chittychittybangbang like this.
  8. Ol'Rattler

    Ol'Rattler Well-Known Member

    Joined:
    Apr 24, 2011
    Messages:
    783
    Car:
    06 TDI Jetta
    Location:
    Marysvile, WA.
    No. wrong. You don't need to pin everything to remove the belt. Remember that the crank pin is the holy grail once it's pinned after that you adjust the cam and pump to get their index pins to fit.
     
  9. aoleks

    aoleks New Member

    Joined:
    Aug 26, 2016
    Messages:
    12
    Car:
    Audi A4 B8 2008 2.0 TDI CR
    Location:
    London, UK
    Say I pin the crankshaft in position and take off the belt without locking the cam and hp. How do I turn the camshaft if the belt is off? The hp can be easily adjusted with a screwdriver, but the cam?
     

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