PapaSmurf Posted October 4, 2007 Share Posted October 4, 2007 I just "finished" swapping an l26 into my 78 z. I changed the timing chain, the distributor, starter, everything to correct this problem and I can not figure it out. At low rpms, there is a loud rattle from the rear of the motor, I thought I didn't tighten the intake/exhaust manifold on well enough. I did though. Nothing seems to be lose or rattling. However the flywheel can move about half an inch in either direction, up or down with no resistance.... Shouldn't be able to do that should it?? The rattle goes away when I put the choke on the rear carburator closest to the noise. It doesnt seem to do much when I choke the front carb. The car seems to need a chance to wind up before any acceleration is felt like my vacuum advance is not functioning. I have a brand new distributor, I installed it TODAY. The vacuum line isn't leaking from anywhere. And the last symptom is when the motor is shut off it diesels for a few seconds LOUDLY with lots of rattlin clankin horror. Is this a bad motor? Did I somehow manage to put the timing chain a tooth off again? I stared at that timing for days trying to find something wrong with it... Quote Link to comment Share on other sites More sharing options...
naviathan Posted October 4, 2007 Share Posted October 4, 2007 Ok the flywheel shifting around isn't right. Was this swap from an automatic? The auto uses longer bolts through the flexplate because of the spacer needed. If those bolts are used on a regular flywheel they won't tighten down all the way. As for the rattling, if it goes away when you choke the rear carb the butterfly on that carb might be loose. Check it over real good and see whats rattling or missing. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted October 4, 2007 Share Posted October 4, 2007 The flywheel symptoms do NOT sound good. Not closely related, but the exact same symptoms on my daughter's Dodge turned out to be a flexplate that had cracked all the way around the crank bolts so that it could also be turned about 3/8" either direction at the ring gear with no resistance. And NOISE, jeez, at idle it was loud, but as soon as any load was put on it (put in gear and driven), it quieted down. Quote Link to comment Share on other sites More sharing options...
SilentNight1647 Posted October 6, 2007 Share Posted October 6, 2007 My guess goes to a broken flywheel, it shouldn't move at all. That would contribute to you noise when idling. If it is dieseling leave it in gear when you shut it off and slip the clutch a bit the extra resistance will keep it from doing that. My '72 does the same thing. Also get a listening stick and listen to each intake runner for a knocking noise that may indicate a bad bearing, drain the oil while your at it look for bearing metal. Good luck with this it took me 2 weeks to track down a noise in a Mustang that turned out to be a rod bearing. Quote Link to comment Share on other sites More sharing options...
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