Hey everyone. I have a Farmall M with a loud knocking noise coming from the number 1 cylinder. Tractor will hardly move,misses and knocks loudly and is definately down on power. If the number one cylinder wire is unplugged the tractor runs without knocking albeit down a cylinder. There is also some oil blow by coming out of the air filter. Anyone have any suggestions? Thanks....
Farmall M Engine Knocking
- Thread starter cm9
- Start date
It sound like you have a sparkplug wire hooked up wrong which is causing big ignition advance in that cylinder. If it was a bearing or a wrist pin they wouldn't stop knocking when the plug was disconnected. It might be two of the 4 cylinder plugs are on the cylinder but only one is firing early enough to effect the engines sound and performance. Any other info on how this occurred. After changing plugs, working on distributor, ect.
When it was off were the plug wires removed. If so there is a slight chance that one plug was put on the wrong plug at the distributor. I don't know the firing order but you might be able to take one plug out at a time and check to see if it is firing around top dead center on each cylinder. If two are out of time try switching them around and see if it makes a difference. Before you go pulling plug wires, label the order of which one goes were.
Kiwi Farmall
Bronze Member
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- Mar 28, 2011
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- Mossburn ,New Zealand
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- 1941 Mccormick Deering Farmall A and 1947 Mccormick Deering W4
Go back to the basics and check the timing of the distributor ,check the cap has number one lead inline with the rotor when at TDC on cylinder number 1.Check plug gaps .It will something simple like that,as these are a basic system.Firng order will be 1-3-4-2 but I am not sure of the rotation.
Checked it out today. Started up no problem but was still knocking. We unplugged the number one wire and it went away. Plugged it back in and the knocking noise was still gone. It did come back after a few minutes. Going to change plugs, wires, cap,rotor, condenser and points tomorrow.......
DJ54
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- IH Farmall 656 gas/ IH 240 Utility/ 2, Super C Farmalls/ 2, Farmall A's/ Farmall BN/McCormick-Deering OS-6/McCormick-Deering O-4/ '36 Farmall F-12/ 480 Case hoe. '65 Ford 2000 3 cyl., 4 spd. w/3 spd Aux. Trans
I'd suggest copper core wires.
art
Super Member
Seen this before, yes number one has something wrong! To miss match plug wires or disconnect them will get rid of the noise because there is no load.