audi a6 (c4) tdi timing

dr red eye

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hi i have a audi a6 2.5 tdi 140bhp manual 5 cyl on the c4 chassis and my cam belt snapped. we got the car in bits put new cam belt on it timed it up and it wont start so we thought timing was out by a tooth so we re-timed it and still nothing is there anybody that can help us sort out this problem cheers
 
which belt snapped? ive done a few belt changes on these engines mostly on transporter vans tho. theres the cam belt on the front of the engine and theres diesel pump belt run off the cam on the other end of the engine.if the cam belt isnt timed correctly then the diesel pump will be out too!

youve changed the belt? how did you get the front crank pulley off? the center bolt is damned tight!

to time the cam up correctly you have to remove the pump belt pulley off the cam and slot the flat tool in. then line the "0" up on the flywheel in the window on the bell housing.
to then set up the pump belt you need to refit and tension the pump belt but dont nip up the pulley. you need to fit a dial guage in the diesel pump and turn the pump slightly to pre-load the pump. watch the dial guage (i cant remember how much you should pre-load it (what you should see on the dial guage), you'll have to find out!) once you have the correct preload you need to hold it there and nip up the pulley.
you can set it up without the dial guage but it wont be 100% and will smoke.the "start of injection" needs to be spot on really. if you have vag com this can be checked afterwards.

if your not far from sheffield i'll come have a look?
 
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The dial reading should be .55. Rather than a dial guage you can watch this as you adjust it on the TDI timing checker on VAG COM. It's fiddly at first as very slight movements make huge differene to advance/****** injection pump timing.
I didn't think this is the same engine as on the T4 2.4/2.5 5 cylinder lump though.
If it is then you can set the basic timing of the injection pump by lining up the notch on pulley and pump itself. You then remove the shim and tighten the 10mm bolt to lock it. If the basic timing is correct it will fire straight up. Once it is, adjust it properly using VCDS and smile as it runs like a dream.
As Murran says if it is the cam belt that snapped then how did you undo the crank bolt because without the correct locking kit you'll be there a ling time.