The dreaded knock. |
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The dreaded knock. |
atmadsen914 |
Dec 28 2008, 11:06 PM
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#1
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Am I sure I like old cars? Group: Members Posts: 45 Joined: 7-September 07 From: Carlinville IL Member No.: 8,087 Region Association: Upper MidWest |
I recently rebuilt a 2.0/4 motor and installed it in my 914. After getting many fuel system issues sorted out I finally was able to drive it a few times but after about 150 miles of driving. It developed a knock. I readjusted the valves and the knock seems to get better but never goes away. The knock is audible from idle to about 1500 rpm then smoothes out. When I roll the motor over by hand I can hear a knock on every cylinder.
The motor is basically stock with the exception of a web cam (73 grind). I am about to pull the motor and start disassembling as the sound does not seem good. However after many hours of tinkering has not gotten worse. Ideas? or do I just get to do it all over again? |
Mark Henry |
Dec 30 2008, 04:36 PM
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#2
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
What was the end play?
Keep rolling it over as you take it out and tear into it, just in case you get lucky. |
atmadsen914 |
Dec 30 2008, 04:49 PM
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#3
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Am I sure I like old cars? Group: Members Posts: 45 Joined: 7-September 07 From: Carlinville IL Member No.: 8,087 Region Association: Upper MidWest |
What was the end play? Keep rolling it over as you take it out and tear into it, just in case you get lucky. My current theory is actually endplay. I fear the flywheel bolts have loosened. (I was not the one who installed them). As the sound seems to be very similar to when you roll the motor over on the bench without the fly wheel attached. I have no play however on the front side but it is difficult to test with the motor in the car. Just a theory at this point. |
brant |
Dec 30 2008, 05:41 PM
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#4
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914 Wizard Group: Members Posts: 11,632 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
What was the end play? Keep rolling it over as you take it out and tear into it, just in case you get lucky. My current theory is actually endplay. I fear the flywheel bolts have loosened. (I was not the one who installed them). As the sound seems to be very similar to when you roll the motor over on the bench without the fly wheel attached. I have no play however on the front side but it is difficult to test with the motor in the car. Just a theory at this point. not questioning your abilities at all but how was the end play when you first built it? I had one with loose end play that I decided would be "good enough" it was on the outside edge of the specifications it broke the crank shaft in two had a horrible knock at idle and deceleration but under load the crank halfs would catch each other on the angled split and the noise would go away... I hope thats not your situation but how was your end play specs when you did your build? brant |
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