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Tann1 09-24-2012 17:59:58 72.171.0.142 Report to Moderator	Recently purchased a 79 cat d3. Engine was overhauled 23hrs ago runs great. I've noticed when cranking before it fires u hear a loud deep clunk or "knock" . U can listen and hear it when running but at that point it doesn't stand out just sounds lika diesel. Noise sounds more lower and rear just not sure what it is. Deffinately not a rod or it would have flung through the block by now being that loud and holds 50lbs oil pressure and once warm almost no blowy. Is this a normal noise for a 3204? Any help is appreciated thanks [Reply]   [No Email]
Tann1 09-30-2012 14:14:00 67.142.130.29 Report to Moderator	Re: D3 engine noise in reply to Tann1, 09-24-2012 17:59:58   I have pulled starter and spun flywheel all way around noticed no bured up or damaged spots just normal wear. Also starter is fairly new replaced by last owner when it "would barely crank over" just a deep knock almost like cracked flywheel or loose converter bolt sound. But those checked out good as well least what I could get visual of. Trying to get all the little kinks Outta this thing is taking longer than expected as usual haha. Get to take track off next weekend to rebuild blown tensioner. So excited bout that. I feel backhoe will be very handy for handling that. [Reply]  [No Email]
Brian Allen 09-30-2012 14:03:02 142.169.215.28 Report to Moderator	Re: D3 engine noise in reply to Tann1, 09-24-2012 17:59:58   As Old Magnet suggested, you need to pull the starter to check for damaged teeth on the ring gear, I suggest doing it before the starter destroys itself. A file should remove any damaged areas on the ring gear teeth that cause the starter to ride up (usually in one spot where the starter first engages the ring gear). Brian [Reply]  [No Email]
tann1 09-25-2012 04:15:11 166.137.88.27 Report to Moderator	Re: D3 engine noise in reply to Tann1, 09-24-2012 17:59:58   The noise is when the engine is cranking but before it actually fires up. Not at initial starter engagement. Notice it more when engine is cold simply because it cranks longer before it fires. I would guess its one knock per engine revolution. Thanks [Reply]  [No Email]
NCWayne 09-24-2012 21:47:39 69.40.232.132 Report to Moderator	Re: D3 engine noise in reply to Tann1, 09-24-2012 17:59:58   You say you hear a clunck or 'knock' before it cranks....have you pulled the starter to insure the bendix isn't buggered up and the sound your hearing is it engaging in the flywheel starter ring? I have also seen starters that would hang up when starting, if the teeth were screwed up. When that happened, instead of kicking out like they were supposed to, they would motor around (((until something blew up or the engine was stopped and they released until the next time,)) and would cause all sorts of odd noises. On the opposite end of the spectrum. I had one in a CAT scraper years ago that made no noise at all until you wound the engine up to a high RPM, and then it sounded like some sort of jet turbine. When pulled the starter was so hot I had to use welding gloves just to get it on the ground as it was too hot to even think about handling otherwise. Good luck and let us know what you find. [Reply]  [No Email]
Tann1 09-24-2012 18:01:30 72.171.0.142 Report to Moderator	Re: D3 engine noise in reply to Tann1, 09-24-2012 17:59:58   Also no difference when hot or cold. Thanks [Reply]  [No Email]
Old Magnet 09-25-2012 07:32:21 108.93.152.109 Report to Moderator	Re: D3 engine noise in reply to Tann1, 09-24-2012 18:01:30   I'd be checking for buggered up teeth on the flywheel ring gear. [Reply]  [No Email]