753g running hot

[bobcatgrant]

Hey guys, Merry Christmas. My 2002 753g is all of a sudden running hot, like to shutdown. when I started it the other day to move it, it didn't sound right. I guess if I had to explain like something was muffled. Anyway that day I was moving it so it run for like maybe 5 min until I shut it off and was done. Went to plow with it this morning and it started fine but still had that different muffled sound. About 10 min into it the temp gauge spiked way up and I could smell antifreeze so I limped it back to the garage where it shut itself off. I opened the back and didn't see any leaks. the coolant overflow jug was where it should be with coolant but I could hear a faint bubbling noise which I cant locate. I let it cool down to open rad cap and it was way low. topped it off and started it again and ran it the temp went up to the yellow on the gauge before I decided to shut it off after a couple of minutes. Help!!! Where should I start??

 

[farmshop]

Fan belt? Separate belt on the left side of the engine. Also check water pump belt on the other side of the engine. Fan belt has a spring loaded tensioner that can wallow out throwing the belt of

 

[foton]

Fan belt? Separate belt on the left side of the engine. Also check water pump belt on the other side of the engine. Fan belt has a spring loaded tensioner that can wallow out throwing the belt of

look at the engine oil just to be sure it does not look milky. it could be a stuck thermostat , also some engines if they develop a air bubble around the thermostat they do not self purge, I do not have a clue if your engine would do that. some engines have a bypass tube others have a v or pinhole in thermostat to let air cycle its way out. hopefully it is not a head gasket. A inferred temp gauge would be handy.

 

[bobcatgrant]

look at the engine oil just to be sure it does not look milky. it could be a stuck thermostat , also some engines if they develop a air bubble around the thermostat they do not self purge, I do not have a clue if your engine would do that. some engines have a bypass tube others have a v or pinhole in thermostat to let air cycle its way out. hopefully it is not a head gasket. A inferred temp gauge would be handy.

oil looked good, belt on the right side was spinning everything. where's the tstat located? could we be thinking water pump? It did have a slight vibration at 3/4 throttle when i did run it when it was cold. no leaks anywhere. looks like my xmas present is going to be kubota motor parts? I do confess im not a diesel mechanic but can turn a wrench or am not afraid to.

 

[foton]

oil looked good, belt on the right side was spinning everything. where's the tstat located? could we be thinking water pump? It did have a slight vibration at 3/4 throttle when i did run it when it was cold. no leaks anywhere. looks like my xmas present is going to be kubota motor parts? I do confess im not a diesel mechanic but can turn a wrench or am not afraid to.

I would think it should be in the upper radiator hose housing connection on the engine. But it can be else where.

 

[farmshop]

I would think it should be in the upper radiator hose housing connection on the engine. But it can be else where.

Thermostat is on top of the engine on the right side. I would still look at the fan belt and the fan drive to make sure it's turning. It is separate from the alternator belt on the other side of the engine.

 

[bobcatgrant]

Thermostat is on top of the engine on the right side. I would still look at the fan belt and the fan drive to make sure it's turning. It is separate from the alternator belt on the other side of the engine.

ok so i went to give it a go today. checked the radiator fuild and it was low. Should it be up the top? i topped it off and let it run at idle till warmup which was about 5 min. Ran it about 5 min at 3/4 throttle and it crept back up to the yellow on the temp gauge before i shut it down. I can smell hot antifreeze somewhere but i can find any leaks on the ground or anywhere. Let it cool and opened the radiator and it was down again. Any clues? All advice is appreciated.

 

[bobcatgrant]

ok so i went to give it a go today. checked the radiator fuild and it was low. Should it be up the top? i topped it off and let it run at idle till warmup which was about 5 min. Ran it about 5 min at 3/4 throttle and it crept back up to the yellow on the temp gauge before i shut it down. I can smell hot antifreeze somewhere but i can find any leaks on the ground or anywhere. Let it cool and opened the radiator and it was down again. Any clues? All advice is appreciated.

also looking for any manual, parts, service, shop to help me out. I thought there was a link somewhere for those.

 

[foton]

also looking for any manual, parts, service, shop to help me out. I thought there was a link somewhere for those.

get a radiator pressure tester pressurize the system to what ever pressure listed on the rad cap on a cold engine and look for leaks, hopefully you will be able to find it then and further internal engine testing can be avoided.(head gasket)

 

[flyerdan]

get a radiator pressure tester pressurize the system to what ever pressure listed on the rad cap on a cold engine and look for leaks, hopefully you will be able to find it then and further internal engine testing can be avoided.(head gasket)

If it isn't showing any leaks, it sounds like it's ingesting it, which, at that rate, should exhibit some pretty good steam clouds out the exhaust.
The pressure tester is a good idea, and a handy bit of kit to have anyway, but you can also run it with the radiator cap off and see if you get any bubbling from cylinder pressure. If you do, that tells you the head gasket is probably the fault (hopefully it's that as Kubota heads are notoriously intolerant of overheating).
753 parts and service can both be found in the V V V thread.

 

[farmshop]

If it isn't showing any leaks, it sounds like it's ingesting it, which, at that rate, should exhibit some pretty good steam clouds out the exhaust.
The pressure tester is a good idea, and a handy bit of kit to have anyway, but you can also run it with the radiator cap off and see if you get any bubbling from cylinder pressure. If you do, that tells you the head gasket is probably the fault (hopefully it's that as Kubota heads are notoriously intolerant of overheating).
753 parts and service can both be found in the V V V thread.

Look closely at the water pump. They can be hard to see leaking there is a weep hole kinda behind the pulley

 

[bobcatgrant]

Look closely at the water pump. They can be hard to see leaking there is a weep hole kinda behind the pulley

Ok so Ive gotten to the problem i think. Took off air cleaner and hoses and removed the belt cover. Looked fine .Started motor and same issues . Well one of the belts is bad as in a higher speed it wont move but at idle it does? Very interesting. Anyway so there are three belts on the left side of the motor, drive (big thick one) one that drives the fan and then this other one thats grooved thats bad. Trying to locate a part number for it. Drive belt is 6726898 and the fan belt is 6715478(says it 40" long) Its this last belt im trying to find a part number for. Its longer than 40"and serrated. Previous owner has writtten in the owners manual that the h2o belt is 6715478 which is wrong. According to bobcat parts fiche it is the fan belt correct?

 

[bobcatgrant]

Ok so Ive gotten to the problem i think. Took off air cleaner and hoses and removed the belt cover. Looked fine .Started motor and same issues . Well one of the belts is bad as in a higher speed it wont move but at idle it does? Very interesting. Anyway so there are three belts on the left side of the motor, drive (big thick one) one that drives the fan and then this other one thats grooved thats bad. Trying to locate a part number for it. Drive belt is 6726898 and the fan belt is 6715478(says it 40" long) Its this last belt im trying to find a part number for. Its longer than 40"and serrated. Previous owner has writtten in the owners manual that the h2o belt is 6715478 which is wrong. According to bobcat parts fiche it is the fan belt correct?

Me dumb. So the i figured it out i think. So Im looking at the drive belt and its only got 2 grooves. It should be 3 right? outside groove was seperated from other 2 Which is why I thought it was another belt. It flipped off/broke and knocked the fan belt off.

 

[farmshop]

Me dumb. So the i figured it out i think. So Im looking at the drive belt and its only got 2 grooves. It should be 3 right? outside groove was seperated from other 2 Which is why I thought it was another belt. It flipped off/broke and knocked the fan belt off.

Yup drive belts are 3 rib. Fan belt is desperate out side of it