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On 16 Aug 2004 at 20:36, jacob.a.schroeder.1 wrote: > I just did a valve job on my squareback this afternoon and once I was done > I started up my car and I heard a knocking noise, and it sounded pretty > bad. A valve job and a valve adjustment are 2 different things. I suspect that you just adjusted the valves. > The noise is definitely coming from the 3rd cylinder and the only way I > can describe it is that it sounds like somebody is hitting a hammer in > there. If I let the car idle long enough it will die because the idle > surges a bit until it swings low enough to die. You say this is a '72. Is this still the original setup with the FI and the vacuum advance and retard distributor? If so, then the only correct timing instructions are in the Bentley manual. Everyone else gets it wrong. Who did you follow? > Here's the odd part... or so I thought. When I disconnect the injector to > cylinder 3, the car starts running "fine" again (fine for running on 3 > cylinders) and the idle stays constant - with no knocking. It's almost as > if my timing is off on that cylinder which is causing it to fire at a > time the cylinder shouldn't be firing, thus its fighting with the > cylinder momentum. I just did a valve job and everything was set to .006 > (I only had to slightly adjust maybe 3 valves that were loose) so I know > the valves are correct. The concern here is that you might have a bad rod bearing, but if this is the problem then it's probably been coming on for some time. There are a couple of things you can check. Using a long screwdriver, put the blunt end in your ear and the other end on various parts of the engine, to try to pin down the point of origin of the noise. It could be a rod bearing (center of case) or a loose cylinder head (cylinder head.) It could just be that you've timed it wrong for a '72. The fact that disconnecting the #3 injector makes it go away just means that #3 is most closely associated with this noise, but it could still have several possible causes. With the engine stopped, rotate it 90 deg past TDC. Get someone to rock the crank back and forth while you listen with the screwdriver. If you can feel the left head move when you do this then the head is probably loose. If the head is tight but you hear or feel a clunk down inside the case, then you probably have a bad rod bearing. Personally, I suspect that a lose head is the most likely cause. > I must add that I'm using Pertronix electronic points, if that adds > anything I'm not sure. Makes no difference. -- ******************************* Jim Adney, jadney@vwtype3.org Madison, Wisconsin, USA ******************************* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ Shameless link for search engines: http://listarchive.type3.org ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~