Farmall m engine knock

JustinC · Nov 11, 2014

I have a 51 Farmall M. Tractor has been redone except for motor. Started smoking a while back from burning oil. Found some oil leaking around the plug on the number three cylinder. Now I am starting to hear a white knocking sound around that cylinder area. Am I thinking correctly on doing a in frame with new sleeves and pistons?

Icuby · Nov 11, 2014

Remove all plugs and take a compression test of all cylinders,that can tell you a lot. Could be only valve adjustment and in need of valve guide seals. Take and hold a wwoden dowl{or something similiar] to the cyl.that is makeing the noise and follow it on down or up to pin point the area of the noise.

Brent Zappe · Nov 11, 2014

It depends on what you find on the engine. Such as is there water in the oil (like mud looking)this could be a blown head gasket.Could just be a sicky valve lifter? Could it be a piston slaping in the cylinder because the skirt is broken off. Most people I know would tell me to try to figure this out before thinking of doing the full engine over haul. Question when was the last time the engine was rebuilt? Question would it be better to rebuild it out of the tractor and make sure every thing is straight,Clean and ready to put together. To rebuild in tractor coast almost the same to do if you pulled it out and rebuild it. I would say about 1,800.00 to rebuild right.

Alan K · Nov 11, 2014

Just to add make sure you check the piston pin bushings.

El Toro · Nov 11, 2014

You should have that crankshaft checked for wear.
Hal

Dick2 · Nov 11, 2014

You could just keep using it until parts come out through a hole in the side of the block - or you could tear into the engine and determine the exact cause of the noise.

Personally, I'd opt for a complete tear down and fix the problem(s).

Janicholson · Nov 11, 2014

Not a Flame, solid lifters don't stick, unless the pushrod, rocker, or valve/spring is or are toast. But I also think as though many engines have hydraulic valves. Jim

notjustair · Nov 11, 2014

I'd bet my lunch there's a rod bearing out in there that has the urge to open a window in the side of that block. An M engine with a rod knock is unmistakable - they really bang.

Farmall m engine knock

JustinC

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Icuby

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Brent Zappe

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notjustair

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