Crankshaft Wont Reach TDC In Either Direction
03-26-2017, 05:20 AM
#11
AudiWorld Super User
Sorry for the bad terminology. My phone changed DIY guide to Fit guide.
No I'm not a mechanic by trade but with the right tools and instructions there's usually not much that I can't accomplish. Yes I make mistakes, I'm human. All I'm looking for is help from more experienced guys like yourself to correct my mistake.
Thanks!
No I'm not a mechanic by trade but with the right tools and instructions there's usually not much that I can't accomplish. Yes I make mistakes, I'm human. All I'm looking for is help from more experienced guys like yourself to correct my mistake.
Thanks!
...but again, which DIY did you use? ...we may need to warn people away from that version(?)
Cheers
03-26-2017, 06:13 AM
#12
Are you absolutely 100% sure the pin was in the hole in the crank, and not in a gap between the counterweights? It can be a little tricky to get the hole lined up if you've not done it before since you can't see directly in to the hole. I use a torch and a small make-up mirror to make sure its right before I put the pin in.
1, can you still get the cam locking bar in place? There's no point taking the covers off yet since the plates for the locking bar are indexed to the cams. If the bar will go in then the cams are definitely where you think they are
2, with the vibration damper back on, where is the timing mark relative to the arrow on the belt cover?
I have a feeling you have got the cams and crank out of sync, but as yet I'm not quite sure how to get them back other than removing the cams which is quite a big job!
Oh btw, never turn these engines backwards with the cam belt on. The belt tensioner setup is designed to work only with the engine rotating clockwise. It slackens off if you turn it backwards and things get out of time.
You should be able to turn the crank back 45* from TDC with the belt removed. This ensures no pistons are at TDC so you can work on the cams without bending anything.
My thoughts at the moment are to get the crank 45* before the mark, and line the cams up with the tool, then see if the crank will go back to 0. Problem is, if its out of sync then you may not be able to get it there. That'll take some thinking about, but I do have a couple of V8 blocks in the shop so I'm sure we can figure it out.
TDC marks on these are for cylinder #5 as said, which is counter-intuitive. That's front right looking at the motor.
Oh, and loosening the cam sprockets is essential to getting proper tension on the belt and correct cam timing. Ignore any marks on the sprockets themselves and use the locking bar as the only reference. The cams are on a taper lock so back out the bolt 1/4" and use a bearing puller to pop them off. As you tension the belt you'll see the sprockets rotate on the cams, then you lock them in place with the bolt once its all set.
(I know I repeated a few things others have said here. Just putting all my thoughts together
)
1, can you still get the cam locking bar in place? There's no point taking the covers off yet since the plates for the locking bar are indexed to the cams. If the bar will go in then the cams are definitely where you think they are
2, with the vibration damper back on, where is the timing mark relative to the arrow on the belt cover?
I have a feeling you have got the cams and crank out of sync, but as yet I'm not quite sure how to get them back other than removing the cams which is quite a big job!
Oh btw, never turn these engines backwards with the cam belt on. The belt tensioner setup is designed to work only with the engine rotating clockwise. It slackens off if you turn it backwards and things get out of time.
You should be able to turn the crank back 45* from TDC with the belt removed. This ensures no pistons are at TDC so you can work on the cams without bending anything.
My thoughts at the moment are to get the crank 45* before the mark, and line the cams up with the tool, then see if the crank will go back to 0. Problem is, if its out of sync then you may not be able to get it there. That'll take some thinking about, but I do have a couple of V8 blocks in the shop so I'm sure we can figure it out.
TDC marks on these are for cylinder #5 as said, which is counter-intuitive. That's front right looking at the motor.
Oh, and loosening the cam sprockets is essential to getting proper tension on the belt and correct cam timing. Ignore any marks on the sprockets themselves and use the locking bar as the only reference. The cams are on a taper lock so back out the bolt 1/4" and use a bearing puller to pop them off. As you tension the belt you'll see the sprockets rotate on the cams, then you lock them in place with the bolt once its all set.
(I know I repeated a few things others have said here. Just putting all my thoughts together
)
Last edited by MikkiJayne; 03-26-2017 at 06:24 AM.
03-26-2017, 07:04 AM
#13
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https://www.audiworld.com/forums/a8-s8-d3-platform-discussion-60/d-i-y-timing-belt-replacement-2887533/
03-26-2017, 07:19 AM
#14
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Are you absolutely 100% sure the pin was in the hole in the crank, and not in a gap between the counterweights? It can be a little tricky to get the hole lined up if you've not done it before since you can't see directly in to the hole. I use a torch and a small make-up mirror to make sure its right before I put the pin in.
1, can you still get the cam locking bar in place? There's no point taking the covers off yet since the plates for the locking bar are indexed to the cams. If the bar will go in then the cams are definitely where you think they are
2, with the vibration damper back on, where is the timing mark relative to the arrow on the belt cover?
I have a feeling you have got the cams and crank out of sync, but as yet I'm not quite sure how to get them back other than removing the cams which is quite a big job!
Oh btw, never turn these engines backwards with the cam belt on. The belt tensioner setup is designed to work only with the engine rotating clockwise. It slackens off if you turn it backwards and things get out of time.
You should be able to turn the crank back 45* from TDC with the belt removed. This ensures no pistons are at TDC so you can work on the cams without bending anything.
My thoughts at the moment are to get the crank 45* before the mark, and line the cams up with the tool, then see if the crank will go back to 0. Problem is, if its out of sync then you may not be able to get it there. That'll take some thinking about, but I do have a couple of V8 blocks in the shop so I'm sure we can figure it out.
TDC marks on these are for cylinder #5 as said, which is counter-intuitive. That's front right looking at the motor.
Oh, and loosening the cam sprockets is essential to getting proper tension on the belt and correct cam timing. Ignore any marks on the sprockets themselves and use the locking bar as the only reference. The cams are on a taper lock so back out the bolt 1/4" and use a bearing puller to pop them off. As you tension the belt you'll see the sprockets rotate on the cams, then you lock them in place with the bolt once its all set.
(I know I repeated a few things others have said here. Just putting all my thoughts together )
1, can you still get the cam locking bar in place? There's no point taking the covers off yet since the plates for the locking bar are indexed to the cams. If the bar will go in then the cams are definitely where you think they are
2, with the vibration damper back on, where is the timing mark relative to the arrow on the belt cover?
I have a feeling you have got the cams and crank out of sync, but as yet I'm not quite sure how to get them back other than removing the cams which is quite a big job!
Oh btw, never turn these engines backwards with the cam belt on. The belt tensioner setup is designed to work only with the engine rotating clockwise. It slackens off if you turn it backwards and things get out of time.
You should be able to turn the crank back 45* from TDC with the belt removed. This ensures no pistons are at TDC so you can work on the cams without bending anything.
My thoughts at the moment are to get the crank 45* before the mark, and line the cams up with the tool, then see if the crank will go back to 0. Problem is, if its out of sync then you may not be able to get it there. That'll take some thinking about, but I do have a couple of V8 blocks in the shop so I'm sure we can figure it out.
TDC marks on these are for cylinder #5 as said, which is counter-intuitive. That's front right looking at the motor.
Oh, and loosening the cam sprockets is essential to getting proper tension on the belt and correct cam timing. Ignore any marks on the sprockets themselves and use the locking bar as the only reference. The cams are on a taper lock so back out the bolt 1/4" and use a bearing puller to pop them off. As you tension the belt you'll see the sprockets rotate on the cams, then you lock them in place with the bolt once its all set.
(I know I repeated a few things others have said here. Just putting all my thoughts together
)Yes I'm 100% sure that the crank was locked in the proper position.
I removed all spark plugs as advised by others and the crank turns easily in both directions until reaching about 45degress above and below TDC.
Like I mentioned above I never popped the cam pulleys off and that seems to be where I went wrong.
Also yes I am able to get the locking bar onto the cams but the crank issue still remains.
Now searching high and low for the simplest way to correct my silly mistake.
Thanks
Last edited by FirstAudi2001; 03-26-2017 at 07:22 AM. Reason: Forget to mention
03-26-2017, 07:34 AM
#15
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First I would like to thank everyone for their efforts in helping me.
At this point I understand that my crank and cams are out of sync. Am I correct by thinking with the crank 45degrees below TDC I should be able to play around with the position of the cams in hopes of getting lucky enough to get everything back in sync. I know it might be a long shot but is my theory at least logical?
At this point I understand that my crank and cams are out of sync. Am I correct by thinking with the crank 45degrees below TDC I should be able to play around with the position of the cams in hopes of getting lucky enough to get everything back in sync. I know it might be a long shot but is my theory at least logical?
03-26-2017, 10:12 AM
#16
AudiWorld Super User
I used the following guide but I believe I went wrong because I loosened the bolts but never actually popped the cam pulleys loose. At this point I know that I have the crank and cams out of scynk. Please tell me that there's a way to correct it without opening the engine.
https://www.audiworld.com/forums/a8-...ement-2887533/
https://www.audiworld.com/forums/a8-...ement-2887533/
You do not actually need to pop the cam pulleys off (I never have on any car, including my D2). And contrary to some beliefs, you may hand turn the crank & cam pulleys against each other and it will not bend any valves ... I and many others have done this ... the contact is absorbed by the hydraulic lifters.
I only use a homemade cam lock (doesn't lock) just to check timing, when the crank is at TDC (#5 ... or bar can't fit)
The cam pulleys have nothing to do with belt tension ... only the eccentric pulley and the damper (5mm gap). The pulleys are "keyed" to exhaust cams, so unless they have been abused by past mechanics, your relative cam timing has not changed appreciably since the engine was made ... now only the cam pulleys relation to the crank pulley matters.
First pull the belt back off ... sorry, but necessary.
Then "allow" (push em) the cam pulleys to move a little (up to 45 degrees easily) and then turn the crank on up to TDC and lock it. Moderate resistance will not hurt anything ... people are WAY too paranoid about valve damage, does not happen in this engine by hand-turning these pulleys out of sync.
Then, turn the cam pulleys back to where the bar will fit and mark their position with paint marks (sharpie) . Fit the belt around the crank pulley first, then rock the cam pulleys (pass side first) to fit the belt on, then over to the other side, and rock pulley back to catch the right teeth for the pulley to go back to proper timing position.
Tension things as normal, then check to see if the bar fits back on properly ... if so, hand the engine again and recheck the bar fitment. If it's off a tooth or more, start again.
If you have already popped off the pulleys, you need to look at the REAL Bentley Manual (Audi) to go through all the steps.
Cheers
Last edited by silverd2; 03-26-2017 at 10:32 AM.
03-26-2017, 10:42 AM
#17
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I looked at that DIY which was on a D3 ... close to the same as D2. At a glance, looked like he took some short cuts (I take WAY more, but that's another discussion).
You do not actually need to pop the cam pulleys off (I never have on any car, including my D2). And contrary to some beliefs, you may hand turn the crank & cam pulleys against each other and it will not bend any valves ... Myself and many others have done this ... the contact is absorbed by the hydraulic lifters.
I only use a homemade cam lock (doesn't lock) just to check timing, when the crank is at TDC (#5 ... or bar can't fit)
The cam pulleys have nothing to do with belt tension ... only the eccentric pulley and the damper (5mm gap). The pulleys are "keyed" to exhaust cams, so unless they have been abused by past mechanics, your relative cam timing has not changed appreciably since the engine was made ... now only the cam pulleys relation to the crank pulley matters.
First pull the belt back off ... sorry, but necessary.
Then "allow" (push em) the cam pulleys to move a little (up to 45 degrees easily) and then turn the crank on up to TDC and lock it. Moderate resistance will not hurt anything ... people are WAY too paranoid about valve damage, does not happen in this engine by hand-turning these pulleys out of sync.
Then, turn the cam pulleys back to where the bar will fit and mark their position with paint marks (sharpie) . Fit the belt around the crank pulley first, then rock the cam pulleys (pass side first) to fit the belt on, then over to the other side, and rock pulley back to catch the right teeth for the pulley to go back to proper timing position.
Tension things as normal, then check to see if the bar fits back on properly ... if so, hand the engine again and recheck the bar fitment. If it's off a tooth or more, start again.
If you have already popped off the pulleys, you need to look at the REAL Bentley Manual (Audi) to go through all the steps.
Cheers
You do not actually need to pop the cam pulleys off (I never have on any car, including my D2). And contrary to some beliefs, you may hand turn the crank & cam pulleys against each other and it will not bend any valves ... Myself and many others have done this ... the contact is absorbed by the hydraulic lifters.
I only use a homemade cam lock (doesn't lock) just to check timing, when the crank is at TDC (#5 ... or bar can't fit)
The cam pulleys have nothing to do with belt tension ... only the eccentric pulley and the damper (5mm gap). The pulleys are "keyed" to exhaust cams, so unless they have been abused by past mechanics, your relative cam timing has not changed appreciably since the engine was made ... now only the cam pulleys relation to the crank pulley matters.
First pull the belt back off ... sorry, but necessary.
Then "allow" (push em) the cam pulleys to move a little (up to 45 degrees easily) and then turn the crank on up to TDC and lock it. Moderate resistance will not hurt anything ... people are WAY too paranoid about valve damage, does not happen in this engine by hand-turning these pulleys out of sync.
Then, turn the cam pulleys back to where the bar will fit and mark their position with paint marks (sharpie) . Fit the belt around the crank pulley first, then rock the cam pulleys (pass side first) to fit the belt on, then over to the other side, and rock pulley back to catch the right teeth for the pulley to go back to proper timing position.
Tension things as normal, then check to see if the bar fits back on properly ... if so, hand the engine again and recheck the bar fitment. If it's off a tooth or more, start again.
If you have already popped off the pulleys, you need to look at the REAL Bentley Manual (Audi) to go through all the steps.
Cheers
I follow everything that you are advising but for some reason the crank wont turn completely to tdc no matter which way I turn the cams.
I can turn both cams 360degrees with out any resistance other than the spring in the cams, I can even get the cam locking bar in its correct position.
The crank rotates freely in both direction until I get close to the TDC marks on the cover.
Any idea on what could cause this problem? As an example, it almost feels as if the crank locking pin is installed but incorrectly. Just to further clarify, the locking pin is not installed as of now.
03-26-2017, 11:45 AM
#18
AudiWorld Super User
Wow ... I'm temporarily stumped, since the engine was running fine before. I'm gonna post a link to this thread over on QW ... and hope someone has other theories on what the "obstruction" is (?)
...stand by.
...stand by.
03-26-2017, 12:12 PM
#19
The cam pulleys have nothing to do with belt tension ... only the eccentric pulley and the damper (5mm gap). The pulleys are "keyed" to exhaust cams, so unless they have been abused by past mechanics, your relative cam timing has not changed appreciably since the engine was made ... now only the cam pulleys relation to the crank pulley matters.
If you don't crack the cam pulleys then you are setting different tension between the crank and bank 1 cam (using the damper) and between bank 2 cam and the crank using the eccentric. You're not setting tension at all between the two cams because they can't move. Doing it this way may work, but its not correct.
Pertinent to the OP's situation, not releasing the cams only prevents the belt being tensioned properly. I don't see how it could have caused the engine to be so dramatically out of time.
Suggestion: with the plugs out, use a small wooden or plastic stick to see which pistons are up at the top. From that we can figure out where the bottom end is right now and possibly find a solution.