'73 175 MF gas..blue smoke sometimes

RandyB(MI) · Jul 26, 2017

Tractor starts and runs perfect. Has been real clean up 'til a few days ago. Tractor has set around idle for much of last 2 years. Couple days ago it started blue smoke, not real heavy but steady and at all rpm. Took down road to get warmed up and wide open in road gear. Still no change. Today started it up to move some other tractors and ran perfectly clean . Moved it to another area and let it set running at around 700 rpm or so. Ran clean for 10 min. Looked over after that and smoke again but cleared up after another 5 min. Just seems to be hit& miss whether it blue smokes. Vent tube is open. New 15-40 Rotella oil. Also did this before oil change but seems to be worse now. Do I need to just put this on a plow and work the crap out of it? Do oil rings set up from non use? Chevy v-8,s used to do this back in the '70,s when the "too small" oil drain back holes in heads would plug up from either gunk or deteriorated valve umbrella seals and would do this same thing. Just wondering if there,s something I'm missing here.

ptfarmer · Jul 26, 2017

Does it smoke when you go from wide open throttle down to idle really quick. That would be intake valve seals, but the way it sounds you may have a oil ring on the pistons sticking.

rockepg · Jul 27, 2017

X2 on the sticky rings. You could put a quart of marvel oil in there and run it arounda bit. That "may" rinse things off enough to function consistently again.
Does the amount of smoke change under load?

nophun · Jul 27, 2017

Sounds like valve seals to me. Maybe shut it down when its smoking and pull and read your plugs once it cools which will tell you which cylinder or all cylinders. As a generalization, ring problems tend to put far more oil in the cylinder which can leave the plugs wet with oil whereas valve seals will foul plugs over time. If plugs look good and stay good, I'd look towards exhaust valve seals leaking and oiling the manifold.

RandyB(MI) · Jul 27, 2017

No, it doesn't smoke more when decelerating which I figured would rule out seals also. Also, usually when it does smoke...it does it right from start up so shouldn't even have oil up in top yet. I haven't had it on a "real" load yet but doesn't seem to change much when out on road and quickly opening up throttle to wide open. I'm thinking the ole guy I bought it from didn't do much with it in maybe last 10 yrs by looking around his place and life situation. My son in law has a perfect little 3-16 mounted Oliver plow I was thinking of mounting up and find a couple garden plots to plow for free just to get it hot and work it. It's a clean engine and quiet and starts/runs so good. Got the AG4-236 Perkins. Sounds like my next move is plowing. I couldn't believe it yesterday when I started it up to move it out of the way, and it never smoked a bit until after about 10 min sitting running. Then after about another 10 min with slight smoke, it cleared up again and I moved it back and revved it up for a while and cleared up again. No rhyme or reason to it.

gtractorfan · Jul 28, 2017

Got a Massey Ferguson 165 that smokes part of the time just like yours. Have used it on a bush hog in tall grass which puts a good load on it, didn't change the intermittent smoking. On a recent oil change I used an additive "no smoke" which didn't change anything.

ptfarmer · Jul 29, 2017

If you want to try something before taking it apart you could pull the spark plugs. Make a 50/50 mix of acetone/automatic transmission fluid, fill the cylinders with it, put the spark plugs back in so the acetone doesn't evaporate. Disable the tractor so it can't be started for a few days while the mix works its way down into the piston rings (the longer it can sit the better). After it sits pull the spark plugs out, crank it over, and see if it spits out any of the mix. The acetone/atf mix could possibly free up the rings, if it doesn't you are going to have to open the engine up eventually anyways. Running, or working it hard usually won't make it better, it will probably make it worse.

RandyB(MI) · Jul 29, 2017

Thanks , Pt , for your post. What baffles me is, if it had stuck ring/rings seems it would do it right when started cold and maybe get better as everything expanded some. How could it start up cold the other day and burn clean for 5-10 min??

'73 175 MF gas..blue smoke sometimes

RandyB(MI)

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ptfarmer

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rockepg

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nophun

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RandyB(MI)

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gtractorfan

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ptfarmer

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RandyB(MI)

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