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 Camshaft and Gear Pressfit loosening 
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Junior Member

Joined: October 08 2009, 2:14 PM
Posts: 3
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Post Camshaft and Gear Pressfit loosening
Hello guys,

I have a big problem back home. My car (K8) was running on the minimum oil level for a month while I was waiting to change it.

It started to knock very slightly and I wonder that it was the HLA starting to lose pressure. One week ago I changed the oil and the noise not only didn't vanish, but also started to increase.

On idle it was quiet, as soon as I rev it a little bit, it increased. The noise started to become very strong, as a hummer knock on the head, but very intermittent, gets quiet, increases a lot, gets quiet... . And some times the engine kills, and sounds as something locked it inside.

When the engine is hot, the starter can't start the engine. Looks like something is locking the engine.

When the engine is cold, it starts normally.

I decided to open one Camshaft Cover to take a look, and this is what I found. The synchro helical gear loosed his pressfit with the camshaft and moved axialy. What I imagine is that it is also rotating in relation to the camshaft, taking the engine out of the timing, and then coming back. That would explain the intermittent knocking noise.

I'm starting to think that something locked the left camshaft, and the axial forces of the helical contact made the gear slips aside. Maybe a hydro lock.
But the questions are:

- What would cause the gear to looses its pressfit?
- I could weld some small points to stick it together, but how the hell i'm going to set the synchro between the gear and the shafts again?
- What else could be damaged?
- The piston has contact with the valves in K8? That means. If the engine gets out of the timing, it's possible to piston to hit the valve?

I'm looking to disassemble the engine today.

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March 19 2015, 8:08 AM
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Joined: March 08 2010, 8:21 PM
Posts: 1523
Location: Canandaigua, NY
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Post Re: Camshaft and Gear Pressfit loosening
are you concerned with the one cam with a split gear? If so thats normal to have them missmatched until they rotate into position, both the front and back banks are set up the same.

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March 19 2015, 10:10 PM
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Junior Member

Joined: October 08 2009, 2:14 PM
Posts: 3
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Post Re: Camshaft and Gear Pressfit loosening
Hey Sleeper, I'm not talking about the backlashless system with two helical gears, if it's that you are saying. This mismatch is normal.

I'm saying about the lower gear, on the picture, that slipped aside. If you look on the first picture, you gonna see a gray line. This is the space between the gear and the camshaft that was not suppose to be there.

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March 20 2015, 7:51 AM
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Joined: March 08 2010, 8:21 PM
Posts: 1523
Location: Canandaigua, NY
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Post Re: Camshaft and Gear Pressfit loosening
honestly I didnt even notice that bit. Ild have to check on mine to see what the spacing is, you can check through my WL but the only pics I think i have up are too small to see. The motor is a non interference atleast so you dont have to worry about internal damage. If it was getting warm and binding Im surprised there isnt any wear marks along the head where the gear would rub as well.

_________________
92 GS gold (driver) worklog> viewtopic.php?f=46&t=73405
93 GS red (wrecked)
:D I modify my ride so I can drive around the stupid people :D


March 20 2015, 9:47 PM
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Regular Member

Joined: March 08 2010, 8:21 PM
Posts: 1523
Location: Canandaigua, NY
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Post Re: Camshaft and Gear Pressfit loosening
maybe these will help give you a reference point for spacing?

http://i1033.photobucket.com/albums/a41 ... G_3509.jpg
http://i1033.photobucket.com/albums/a41 ... G_3510.jpg

_________________
92 GS gold (driver) worklog> viewtopic.php?f=46&t=73405
93 GS red (wrecked)
:D I modify my ride so I can drive around the stupid people :D


March 20 2015, 9:52 PM
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