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Recently, I replaced my timing belt, water pump and belt tensioner. Everything looks fine but I noticed something. With the old tensioner (17 years old), the old belt would sit at slightly different position on the pulleys. I mean when I tensioned the old belt with the old tensioner and cranked the engine by hand (to take up belt slack), the belt walked a little more and sat on a different position on the pulleys but with the new belt and new tensioner, the belt walks a little less before sitting in its place. The following picture shows belt location on intake pulley (with the old and new tensioners).

enter image description here

Should the new belt sit at exactly the same position on the pulleys with the new tensioner like the old set up? Is this normal that the new belt walked less than the old one after cranking the engine by hand? New belt tensioner has been installed and tightened properly like the old one.

This is a side by side comparison:

enter image description here

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  • That belt looks too small, should match the width of the pulleys...
    – Solar Mike
    Aug 5 at 8:51
  • It is the original OEM belt for the car and is the right size. Aug 5 at 9:02
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    @SolarMike I think it looks thinner than it really is due to the shadow caused by the timing cover and the camera flash.
    – HandyHowie
    Aug 5 at 10:00
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Lets sum it up:

  1. You used the right parts.
  2. The pulleys are synced.
  3. The tension is correct.
  4. All the bolts are tightened.
  5. The belts rests at the correct position onto the pulley.
  6. You checked the alignment of the tensioner pulley.
  7. After several revolutions of the crankshaft by hand the points above are still correct.

If all the points above are matched, then I'd consider this job done correctly.

The fact that the camshaft pulley settles in an slightly different position I'd consider as irrelevant. Maybe it is a sign that the old and new tensioner bearing have different running resistance, either the old one was worn or the new bearing needs some run-in. Maybe the old belt became stiffer. Maybe the new belt has a slightly different stiffness. Perhaps there was some misalignment of the tensioner before (that your engine survived by some miracle) and you corrected that. In the end it is irrelevant.

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  • Thanks a lot for your answer. Yes, I tensioned the belt correctly and tightened tensioner bolt. Then, I cranked the engine by hand and the belt walked into its place (the position you see in the above picture with the blue arrow) and remained in its position. Aug 11 at 15:54
  • After that, I cranked the engine more and more to make sure it doesn't walk and it didn't. I even started the engine and let it run for 20 minutes and revved it a bit and the belt stayed in the new position again. It seems that the belt insists on this new position. Aug 11 at 15:55
  • The only thing I didn't understand is that you said: The belt rests at the correct position on the pulley. How do you recognize the correct position of the belt for each car? Aug 11 at 15:57
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    With "correct position" I intend that the belt stays in the center of the pulley, as it does on your car.
    – Martin
    Aug 11 at 19:28
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The new position looks like it is more correct than the old position, which looked too far back.

Looking at the location of the tensioner, wear would likely cause the tensioner pulley to tilt up at the front, which could cause the belt to move back on the pulleys.

Was there much play in the old tensioner?

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  • I forgot to check play in the old tensioner but this is what I noticed with the new tensioner that the belt walked less and didn't go as far back on the pulleys as the old one. I just wanted to know if this is normal that the belt walked less? Is it dangerous to start the engine with the new position? Aug 5 at 9:00
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    Turn it over several times by hand. You could even disconnect the ignition and turn it with the starter to feel more confident. As long as it sits well away from the edges and you have it tensioned correctly you should be fine.
    – HandyHowie
    Aug 5 at 9:28
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    The new belt looks fine from that angle. How much of the pulley is visible on the rear side of the belt that I can’t see?
    – HandyHowie
    Aug 11 at 12:14
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    I would be happy with that outcome.
    – HandyHowie
    Aug 11 at 12:23
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    It sounds like you have done everything correctly. Correct tensioning is vital for longevity. If you are confident you have tensioner it correctly, you should no problems with the belt. Well done.
    – HandyHowie
    Aug 12 at 20:27

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