Water Pump or Thermostat????

MotorSeven · Aug 23, 2011

I check fluids regularly and glance at the temp gauge frequently. Today I took a load of logs up to the house site, off loaded and shut the tractor down. I heard something new after the engine was off...kinda a whirring noise....hmmm, that was odd. About 6 hrs later I started it up and it struggled, then white smoke out of the exhaust. I shut it down and pop the hood. Coolant is blowing out of the overflow tank. The tractor was not up to temp, so I opened the rad cap and had to add over a gallon of water. Started it back up and water is shooting out of the rad fill hole and the overflow tank??? The whole system seems to be under pressure, so I shut it down and can hear water gurgling back into the block for about 30 seconds. So, is it a water pump or thermostat failure? An I assume I have blown the head gasket since I had white smoke.

Drat....bad timing as I have hay to bale tomorrow...........

RickB · Aug 23, 2011

My money is on a blown head gasket.

PoorMansCat · Aug 23, 2011

You have a blown head gasket... Sorry for you misfortune... THis seems to be a re-occuring theme with the little Kioti engine... hhhmmmm...
Make sure you replace all the cylinder head bolts when you replace the head gasket.. Also, make sure you have a competent machine shop surface the head. The proper finish on the head gasket surface is CRITICAL.. "Smooth as a babys but" is NOT what you want.

Coyote machine · Aug 23, 2011

Ditto on the head gasket. How many hours on the engine? Sorry to hear of the bad luck and timing, but better in the yard than out in the fields, yes? Anything blocking air flow to the radiator? Any signs leading up to the failure?
Check your oil level too to see if it is high due to possible coolant flowing into the crankcase. Even if it's normal change it and the filter when you put the engine back together. De-carbonize your piston heads while you have it apart as well.

MotorSeven · Aug 24, 2011

Y'all were right, blown head gasket. PMC, yes Kioti has had some problems with head gaskets but the mechanic said mostly on the DK55's & Ck20's. Thanks for the tip on machining and bolts I wil make sure that gets done. He has only seen a few on the 30, 40 & 45's. Kioti has issued an updated version of the gasket for the 55's.

I did the paper towel test of the oil which showed water in the oil & the oil level was a half inch high. On a good note I am still under warranty until 6/12 & they said it will be about a week.

No signs leading to failure, no blockage other than the normal pre-screen when hogging(I always watch the temp gauge) and I stop and clean it as soon as the gauge rises a bit. I'm at 520 hrs.

Ok, no explain something to me. Why the over pressurization and the failure of the water to circulate? I thought it was going to be a thermostat stuck closed, but the mech said, "no those are the symptoms of a blown head gasket". In a gas engine the water will continue to circulate even with a blown gasket, so why does on on a diesel stop the flow and try and blow it out the overflow and fill hole?

amaxwell · Aug 24, 2011

Extra high compression of a diesel engine???

PoorMansCat · Aug 28, 2011

Not sure if this will answer your question, but a head gasket can "blow" is several different forms. The one that it sounds like you have experienced is the most noticable... t has failed and allowed combustion gasses into the cooling system. With 10psi. of coolant pressure in the radiator and up to 500 lbs of compression and "tons more" of combustion pressure, it doesn't take much to push the fire ring out and find its way to an area to relieve that pressure. THis could be to a head bolt hole, oil passage, or like yours, to a coolant passage.
I have never seen the inside of a Kioti engine, but some general things to look for would be to check the cylinder head for warpage, top of the cylinder block for warpage, around the tops of all cylinders for low areas. Also, the surface finish should be correct to factory spec. for the gasket surfaces. If this is too smooth, the gasket will creep under the head and blow again. Not sure if Kioti requires it, but it may be wise insurance to run the tractor for an hour or two at light load after repair then shut down, allow to cool, and re-torque all the cylinder head bolts again.

MotorSeven · Aug 28, 2011

Thanks PMC for the info!

MotorSeven · Aug 30, 2011

I called yesterday and they have not got to it yet. I have hay that needs to be put up and load/deliver so I asked for a loaner. The owner said, "come pick one out" :thumbsup:

He had a DK55 but it was a cab and way too new(demo), so I picked a demo Mahindra 55 horse shuttle shift. I guess I just don't get the whole shuttle thing, it almost requires the same motions as a gear tractor. The Mahindra ran great and has a beast of a loader on it, but man o'man after 45 min of stacking 4x4's in the barn......I miss my HYDRO:laughing:

blue262 · Aug 30, 2011

Search the post for kioti blown head gasket and you will find my posts and pictures of my CK-25 that blew a head gasket last december at 500 hours. Same symptoms as yours. I got to do my head gasket job twice because I didn't change the head bolts the 1st time and one popped while I was torqueing it. It's a simple little engine to work on and doesn't take long to replace the gasket and reset the valves.

The head gasket design sucks..very little gasket margin around the coolant holes.