'87 S4 Timing Death
#61
#62
Rennlist Member
Also be sure to check that the PKT bracket is still securely fastened to the block. One of the previous failures involved a fracture of the countersunk screw under the tensioner with the two flange-heads being loose.
#66
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
The Conti belts are known to be "stretchier" than the Gates, adding another tension wildcard into the mix. So probably not a good choice even for testing purposes.
The PorKen tensioner is tough to get a tension reading on, since it moves as you test the tension. For sure it's impossible with the Kempf tool; as you twist the belt to get a reading, the tensioner retracts, diddling the reading. It may be possible to get a reading with the later factory tool, but since it too measures difference as it distorts the belt, it may have the same limitations.
I'm close to the opinion that the only way to validate belt tension with Ken's tensioner is using the sonic method, getting a specific resonance when the belt is "plucked".
The PorKen tensioner is tough to get a tension reading on, since it moves as you test the tension. For sure it's impossible with the Kempf tool; as you twist the belt to get a reading, the tensioner retracts, diddling the reading. It may be possible to get a reading with the later factory tool, but since it too measures difference as it distorts the belt, it may have the same limitations.
I'm close to the opinion that the only way to validate belt tension with Ken's tensioner is using the sonic method, getting a specific resonance when the belt is "plucked".
#69
Former Vendor
Now that we all have our own theory....with valid reasons why we do/do not use certain parts....probably time to sit back and wait until the belt area is taken apart and see if any of the ancillary parts broke.
Eliminating cam breakage, water pump seizing, cam drive hub breakage, tensioner hardware breakage, etc. would be a prudent thing to do.
All the individal belt components can be on the workbench in 20 minutes, from the above pictures.
One immediate thing struck me as strange, but I have zero experience to know the answer....
Should the tensioner be able to be compressed with an 8mm Allen on the tensioning wheel?
Eliminating cam breakage, water pump seizing, cam drive hub breakage, tensioner hardware breakage, etc. would be a prudent thing to do.
All the individal belt components can be on the workbench in 20 minutes, from the above pictures.
One immediate thing struck me as strange, but I have zero experience to know the answer....
Should the tensioner be able to be compressed with an 8mm Allen on the tensioning wheel?
#71
Yes you use the tensioning wheel, I use a 8mm Allan socket coupled with a ratchet. Steady pressure and it moves back slowly. I don't think I could do it with just an Allan key.
#72
You can but your hand hurts after it's done. It's not an easy thing to press back in to position. The piston does not retract quickly but with steady pressure it does.
#75
Captain Obvious
Super User
Super User
Another thing to consider is that the Audi tensioner keeps the belt a lot looser on the cam gears than the stock system. When the engine is at rest and cold, you can pull the belt off the cam gears with nothing more than your finger tips. I know this because I did this last summer. Combine this with machined heads that are at or bellow the factory spec and a maxed out Audi tensioner and you got yourself the answer on what happened here.
It's easy to measure if the head was resurfaced to below the factory limit. Maybe start there.
By the way, that belt looks perfectly fine, no sign of heating up from a siezed water pump or any other roller so, that theory can be dismissed.
As for why the cams are advanced, it's possible the crank skipped so much that it stopped where the cams now look advanced.
It's easy to measure if the head was resurfaced to below the factory limit. Maybe start there.
By the way, that belt looks perfectly fine, no sign of heating up from a siezed water pump or any other roller so, that theory can be dismissed.
As for why the cams are advanced, it's possible the crank skipped so much that it stopped where the cams now look advanced.