Blowby

Have gas 4 CYL.tractor 55hp range 4000hrs plus,has some blow by at times.What/When I should be really cocerned and start repairs?What repairs?

Usually rings.

ALL engines have some blow by it is fact of life. Now when you get to the point you check the gas and fill the oil it is time to rebuild it but if your say burning a quart of oil once a week and using it hard no big deal

Some blowby at times? Explaining that in more detail would help us help you.

Years ago a neighbor had a 656 IH diesel that had blowby so bad he would tie a gallon jug under the blowby pipe.At the end of a hard day he would dump that oil back in the engine.It ran for years like that as it was his big tractor and he had no money.

Wondering why you have blowby... Also consider all engines have some blowby, it may be more noticeable in cold weather, as in water vapor being boiled off as the engine warms.

Do you know the history of the tractor? Maintenance, as in air filter care, oil changes? Has it sat outdoors for years unstarted? Traumatic events, overheated, run/sat with bad head gasket? All these factors can affect the rings ability to seal. If you suspect something along these lines has happened,or the problem quickly gets worse, associated with any abnormal noises, it may be time to go in and do some repairs.

Several determining factors as to when to do repairs. Excessive blowby is typically caused by worn compression rings, something that normally occurs to any engine over time.

If what you are seeing is a steady, light flow of smoke coming from the breather tube, more so under load, it's worn rings.

If you see a hard "puffing",as in one cylinder is blowing by, probably associated with idle misfire, and fouling of one plug, there could be a more serious problem, like a damaged piston, broke or stuck rings that have lost their ability to seal. This is more serious and should be looked into soon.

If it's just worn rings, a lot depends on how much you use it and who uses it. If you are the sole user and know it's habbits, like how often to check/add oil, you can get by for a long while. As the wear progresses, problems will slowly increase, as in oil consumption, fouling plugs, loss of idle quality, and loss of power.

Will it damage the engine to keep running this way? Not really, that is if it's just normal wear. By the time it gets worn to the point it's not practical to keep going, it will be time for a complete overhaul where everything will be made right again.