Does engine need rebuilding, Yanmar 1500

swmillbrook · Oct 4, 2013

Yanmar 1500 was on a hill, nose pointed downward, while operating a posthole digger in idle position. Engine got very hot. It will still run but makes a different noise and not as much power as before. Haven't checked for metal flakes in oil yet. If none are present, is there something else to check before diagnosing an engine rebuild?

clemsonfor · Oct 4, 2013

If anything i think you may have blown a head gasket? How much oil is in the tractor? The hill should not of mattered unless you were really low on oil, these tractors dont have a sump its just a flat plate. Whats the oil level now, did you have to refill after say 3 qts? Start tractor and look in the radiator with the cap off and see if you see bubbles in thier indicating a blown head, or oil in there or water or coolant in your oil, which indicates a blown head.

Dont say for sure your bearings are shot.

winston1 · Oct 4, 2013

Does it have a knock? Is exhaust smoke different than before? Are you thinking slope maybe caused oil pressure loss?

deepNdirt · Oct 4, 2013

Not sure this suggestion would help

but what was the fuel level while sitting on a hill? sorry! I always try ruling out the simplest of things and then move on to the more complex things,

Gale Hawkins · Oct 4, 2013

If it does not have a water pump and the front end was pointed down could that not impact thermal coolant flow?

Car Doc · Oct 4, 2013

fwtw My engine has the oil pickup at the front of the engine so if his does also that wouldn't be a concern running low on oil because its tilted. Probably a radiator issue of some kind plugged with seeds or tubes inside plugged or fan belt slipping. There is always the chance it had issues before and now they are just bigger. my .002

deepNdirt · Oct 4, 2013

Gale Hawkins said:
If it does not have a water pump and the front end was pointed down could that not impact thermal coolant flow?

Maybe! if perhaps the catch bottle was leaking and loosing enough coolant, would be certain to run hot, But you have made a good point, It would be difficult for this type of cooling system to force coolant into area's of the engine if not enough pressure pushing it, I would think if the coolant level became low enough there could be some area's on the upper side of the one cylinder wall while in an angle not receiving adequate coolant,

When reading back I see the OP stated was in Idle when running hot, I've noted my 1700 will run warmer at idle than at a higher RPM, could had something to do with it, Just like cars setting idle with the A/C on will run a bit warmer, Got to get air through the radiator in order to keep the water temp down,