muncieman Posted August 16, 2022 Share Posted August 16, 2022 Does anyone have an exploded view of a Mack ENDTF 673 Engine or pictures of the front cam and crank gears. Trying to isolate an issue I am having with my 65. I am having a tapping noise that comes and goes and using a stethoscope it sounds like in front of number 1 Cylinder. It is more profound at idle. At times after it heats up, it goes away but re appears. Thanks Quote Link to comment Share on other sites More sharing options...
Full Floater Posted August 17, 2022 Share Posted August 17, 2022 Are the valves adjusted to spec? Quote Link to comment Share on other sites More sharing options...
fjh Posted August 17, 2022 Share Posted August 17, 2022 (edited) 21 hours ago, muncieman said: Does anyone have an exploded view of a Mack ENDTF 673 Engine or pictures of the front cam and crank gears. Trying to isolate an issue I am having with my 65. I am having a tapping noise that comes and goes and using a stethoscope it sounds like in front of number 1 Cylinder. It is more profound at idle. At times after it heats up, it goes away but re appears. Thanks Be careful! on this ! Mack played about with 2 piece pistons in the this era the skirts can break up! Pull the pan and look at the piston skirts on the cyl you suspect! Edited August 17, 2022 by fjh 1 Quote Link to comment Share on other sites More sharing options...
muncieman Posted August 17, 2022 Author Share Posted August 17, 2022 Yes the valves are adjusted to spec. I never thought of the piston skirt but the noise comes and goes. We changed the no. 1 injector but it still makes the sound. I'm going to investigate further. Thanks for the input Quote Link to comment Share on other sites More sharing options...
fjh Posted August 17, 2022 Share Posted August 17, 2022 1 hour ago, muncieman said: Yes the valves are adjusted to spec. I never thought of the piston skirt but the noise comes and goes. We changed the no. 1 injector but it still makes the sound. I'm going to investigate further. Thanks for the input Another thing you could try is putting an extra gasket under the fuel transfer pump to lessen the side load of its cam shaft ! Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted August 17, 2022 Share Posted August 17, 2022 "F' I am not smart on the E-6.. but I wanted your opinion about the endplay screws/button's, in the front cover. is it possible that the cam is walking, and causing a different sound? I have one in my shop, and I expect to get back to it and get it done this year, I have the book on setting the endplay,, but was curious about noise, after reading this post.. jojo Quote Link to comment Share on other sites More sharing options...
fjh Posted August 17, 2022 Share Posted August 17, 2022 (edited) Guess anything is possible joe how ever I highly doubt his cam button has become worn! It’s easy enough to set think it’s a half turn loose idea! The older engines you could take the big bolt off the side of the transfer pump and detention the spring with an extra washer ! I suggested the extra gasket cause chances of finding an extra washer for that bolt would be slim to none these days! As for the button it’s an easy check for sure!chances are the bearings on the fuel pump cam are worn some and he has some deflection of the cam caused by the pump! Causing a fuel knock on cylinder 1 ! Edited August 17, 2022 by fjh 1 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted August 17, 2022 Share Posted August 17, 2022 How 'bout I just read what you post, and soak up the knowledge?? I like these post's because guy's like you teach me something, that will pop into my head later, when I'm on the job.. jojo Quote Link to comment Share on other sites More sharing options...
Popular Post fjh Posted August 18, 2022 Popular Post Share Posted August 18, 2022 (edited) 16 minutes ago, Joey Mack said: How 'bout I just read what you post, and soak up the knowledge?? I like these post's because guy's like you teach me something, that will pop into my head later, when I'm on the job.. jojo All good anything I can past on I do! The intermittent nature of this issue makes me think this is what is going on how ever can’t rule out the skirt issue unless you look! They usually didn’t live long but there still maybe the odd engine out there with these pistons! Your no slouch in the info department your self ! I also enjoy reading the posts you make ! A Wealth Of info ! If it helps anyone here its a bonus! Edited August 18, 2022 by fjh 2 1 Quote Link to comment Share on other sites More sharing options...
Popular Post muncieman Posted August 19, 2022 Author Popular Post Share Posted August 19, 2022 So I figured out what was going on. The truck had sat in different places over the past 10 years and had several people working on it. We were able to isolate it to number 1 cylinder and bought a rebuilt injector thinking it may of been bad. Turns out that someone had it out already and had left the copper washer in it. I pulled the old one out and a washer was on it, however I did not know another was down in so I installed the new injector and sure enough...tap,tap,tap.. I took it apart and looked down with a flash light and was surprised to see it. It was removed, carbon cleaned up and new injector installed and bingo... noise went away. Thank you again for all of your advice. I appreciate it. This is a great site for old Macks 3 1 Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted August 19, 2022 Share Posted August 19, 2022 based on passed events I can tell you your not the first to find two brass washers in a hole; i never heard of one causing a tap noise. like has been said by many here; life is always a learning experience . Quote Link to comment Share on other sites More sharing options...
fjh Posted August 19, 2022 Share Posted August 19, 2022 Good find buddy! Obviously not something I would have been my first go to! Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted August 19, 2022 Share Posted August 19, 2022 That is awesome.. I'm so glad it was a simple fix.. I feel like most of the time, the cause is something simple.. It was good of you to post the fix. I bet it ''Purr's like a Dog'' now... jojo Quote Link to comment Share on other sites More sharing options...
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