KNOCKING SOUND IN TIMING BELT?

  • Tiny
  • Jeremilorenti
  • 1997 VOLKSWAGEN JETTA
  • 81,000 MILES

So the other day I went to start my 1997 Jetta GLS 2.0, and it didn't want to turn over, but finally did, only to have it stall one second later, and have a puff of white smoke come from my engine. When I looked, the timing belt had snapped off. With this car it has a dual V belt setup. The thicker belt had snapped off. (The one on the crank, alternator, and ac compressor).

I went to try and start the car again, and it started right up, perfectly. Sound clean, and drove smooth.

I bought a new timing belt and put it on, and now the car struggles to start up again, and when it is on, there is a LOUD knocking sound coming from the area of the belt. Also, the car and electronics feel like it has surges or energy. Lights dim, idle goes down, etc.

Keep in mind though, that when the belt was off, the car was fine.

What could this be?

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Wednesday, September 26th, 2012 AT 4:27 PM

21 Replies

  • Tiny
  • KHLow2008
  • EXPERT
  • 41,981 POSTS

That is not the timing belt. It is the serpentine belt and symptoms indicates possibly one of the alternator or A/C compressor being seized. Remove the belt and manually turn the alternator and A/C to see which is not turning.

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Wednesday, September 26th, 2012 AT 6:20 PM
  • Tiny
  • Jeremilorenti
  • MEMBER

Ah I see, my mistake.

When I changed the belt yesterday, I did check to see if the pulleys moved, and the alternator moved freely, but not where it would just spin continuously. The AC pulley however, did not budge with me trying to hand turn it.

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Wednesday, September 26th, 2012 AT 6:46 PM
  • Tiny
  • Jeremilorenti
  • MEMBER

Might help you to know that prior to changing the belt, there was a lesser knock, but still a loud one.

And my AC never worked, as in it would not blow out cold air.

This leads me to think it is the AC Compressor that is causing this.

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Wednesday, September 26th, 2012 AT 6:50 PM
  • Tiny
  • Jeremilorenti
  • MEMBER

Also I just checked, the AC pulley does spin when the car is on, but it is very shaky. It pivots a lot.

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Wednesday, September 26th, 2012 AT 7:35 PM
  • Tiny
  • KHLow2008
  • EXPERT
  • 41,981 POSTS

You seem to have a bad A/C bearing problem if it waves a lot while turning and is the main cause of the belt shredding/snapping.

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Thursday, September 27th, 2012 AT 5:52 AM
  • Tiny
  • Jeremilorenti
  • MEMBER

I replaced the AC Compressor with a Bypass pulley and also replaced the alternator.

Now the car has NO knocking sound.

Seems like it's all fixed EXCEPT now the belt squeals LOUD when I accelerate or turn the steering wheel.

I don't believe the belt is loose, as I could not get a 1130 sized belt on but was able to get the next size up, being a 1170 or something around there.

It was a bit difficult to get the belt on even with the tensioner pulled back all the way.

Do you think the belt could be too tight? Would that cause squealing?

Also, when the belt was off, my steering was extremely smooth and easy, but now with the belt, in addition to the squeals, the steering is extremely hard and rough.

What could it be now?

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Thursday, October 4th, 2012 AT 10:13 PM
  • Tiny
  • KHLow2008
  • EXPERT
  • 41,981 POSTS

I believe the power steering belt tension is too loose. An oversized belt might not have sufficient tension even if it is adjusted to maximum.

Belts do not slip onto the grooves easily. After getting part of the belt onto the groove, you need to turn the crankshaft to let it slip in.

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Thursday, October 4th, 2012 AT 10:27 PM
  • Tiny
  • Jeremilorenti
  • MEMBER

Why would the steering be easy when the belt was off?
Wouldn't that mean the powersteering pump wasn't even being powered?

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Thursday, October 4th, 2012 AT 10:28 PM
  • Tiny
  • Jeremilorenti
  • MEMBER

And I think the belt is tight, personally.

The belt size I tried prior to this one was not long enough and would not go on the pulley, but this one does, but was hard to get on.

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Thursday, October 4th, 2012 AT 10:30 PM
  • Tiny
  • Exovcds
  • MEMBER

KHLow2008 is talking about the V belt (the one that runs the water
pump & power steering).

http://www.germanautoparts.com/Volkswagen/Jetta/Engine/15/4

You are talking about the serpentine belt that you replaced.

If I am reading things right...

Thomas

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Thursday, October 4th, 2012 AT 10:41 PM

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