What ^^ he said!! I don't remember ever seeing a cracked block on a Kubota that hadn't been frozen. Lots of cracked heads though! ( and bent rods!!)
Overheating problem
- Thread starter TexasGlenn
- Start date
A stupid question but would the bent rods show any symptoms? When I start it and let it idle it starts easy and idles smooth.
I believe he means bent connecting rods, not push rods. You hydrolock a diesel, it bends the con rods.
Well everyone, The wife and I decided to bite the bullet and I’m going to try the head gasket and see what the head looks like. Probably try to start next Saturday. I ask for your prayers for knowledge and ability. It’s been 37 years since I’ve been that far into a engine with a year of auto mechanics and a year of Ag mechanics in high school. And those were a 52 flathead Ford 6 cyl and a 8N Ford tractor!
Any obvious do’s and dont’s? Can I get by with just the head gasket ($100) or do I need the upper gasket kit ($240)?
Thank you again.
Any obvious do’s and dont’s? Can I get by with just the head gasket ($100) or do I need the upper gasket kit ($240)?
Thank you again.
Generally it is unusual to be able to replace just a head without removing exhaust manifold, intake manifold, valve cover, etc., so if these gaskets come in the kit then it probably is best to purchase.
If I'm that deep into it with labor, I like to replace what I can given the likelihood it will need servicing and thus repeating the disassembly... Generally saves time and aggravation in the future.
Good luck and keep us posted on how it goes.
bent connecting rods cause the compression ratio to be lower than it should be. this causes harder starting and rough running when cold. They will usually smoke a little more than normal to. If your tractor isn't showing these signs you likely don't have bent rods. It IS a good idea to check piston protrusion when you have the head off though! Just checking that they all are very close to the same is sufficient because it would be rare that you would bend all the rods.
In general, take pictures of the cylinder head before and after cleanup. There are guys on this forum who can spot a crack with a glance.
Cleaning the block and head are not like the old days because the newer engines have softer metals. So do not use metal razor blades or steel knives to clean and scrape. Do not use the fiber sanding pads as they disintegrate and will get into the moving engine surfaces. Read up on the new techniques as the newer gaskets require flat surfaces.
Do not use any sealant with the gasket unless Wolfman gives you advice to do so.
Cylinder head seating is critical. Bolts need to be clean and oiled. Clean out block threads so you get a true torque reading.
Torque wrench needs to be calibrated. Get a digital torque block from Harbor Freight to check your torque wrench. Do the entire torque sequence in three lifts, from 1/3 to 2/3 to full torque.
The labor part should go fairly quickly, except for cleaning, and getting the parts. If the cylinder head has a crack, let the forum know. Sometimes a member has a hard to find part.
While you are in there, you may want to check valve clearance.
Cleaning the block and head are not like the old days because the newer engines have softer metals. So do not use metal razor blades or steel knives to clean and scrape. Do not use the fiber sanding pads as they disintegrate and will get into the moving engine surfaces. Read up on the new techniques as the newer gaskets require flat surfaces.
Do not use any sealant with the gasket unless Wolfman gives you advice to do so.
Cylinder head seating is critical. Bolts need to be clean and oiled. Clean out block threads so you get a true torque reading.
Torque wrench needs to be calibrated. Get a digital torque block from Harbor Freight to check your torque wrench. Do the entire torque sequence in three lifts, from 1/3 to 2/3 to full torque.
The labor part should go fairly quickly, except for cleaning, and getting the parts. If the cylinder head has a crack, let the forum know. Sometimes a member has a hard to find part.
While you are in there, you may want to check valve clearance.
I’m starting to prepare for the job. I can’t seem to find much information on this engine. According to tractordata.com the engine is a Kubota F2803 5 cylinder. Does anyone have the sequence and torque specs for the head bolts?
So I have been monitoring the thread by three oaks since it seems we have similar problems. I noticed he ran the exhaust gas and pressure tests and they both turned out no leaks. So now I’m getting cold fee about diving into the head right away. Do y’all think it would be a good idea for me to do those tests first? And possibly the water pump? Or should I go to the head this weekend?
Water pump lack of circulation you might check with laser thermometer.
Radiator, hoses, thermostat, engine oil level = all checked(?)
Of course, we're not looking for extra unneeded work.
If the problem is now a gasket, then the cylinder head will crack - more dollars.
If the cylinder head cracks, then damage can happen quickly.
For myself, I would rather open it up and have a look. And would rather pick my time to do it so the tractor is not down at a critical time when I need to work it.
Only you know your schedule and where you are willing to roll the dice.
Ran some more tests. Got a block tester and pressure tester through Orielley’s loaner program. The block tester said not for diesel engines. What would be the difference? I ran it anyway at idle and at PTO speed. The fluid remained blue. I let it run for about 20 minutes at PTO speed and checked the hose temperature several times. The temperature was within 2 degrees at the top hose and bottom hose. I took the top tank temperature and it was 209 degrees. The gauge read about 1/4” from the red. Let it idle about 3 minutes and it went down to about 3/4 gauge. Let it cool down about a hour. Tested the cap at 13 psi. In 3 minutes was down as 10 after 15 minutes was at 4 1/2 psi. Pressured the system. After 20 minutes dropped 1 psi. Noticed moisture around the thermostat housing. Never put the thermostat back in and old gasket. Also the belt seems tight enough but I have the alternator as far as it will go on the bracket.
So I have a thermostat and gasket, fan belt, and radiator cap coming. Should I have the radiator rodded or check the water pump? Never thought to check for bubbles in the radiator this time? Wonder what could have caused them before?
So I have a thermostat and gasket, fan belt, and radiator cap coming. Should I have the radiator rodded or check the water pump? Never thought to check for bubbles in the radiator this time? Wonder what could have caused them before?
The inlet and outlet temperatures should NOT be the same if the cooling system is working.
Several items come to mind in this case:
1. Thermostat stuck closed, but it seem this is not currently in the system when the above data was taken. If true, this is not the problem.
2. Water pump not pumping coolant through radiator/block. Is the pump pulley rotating? Draw a line on the pump pulley to make it easier to observe if it is rotating proportionately to engine RPM. Yes, see number 3, No fix water pump or belt system see 4
3. With no thermostat installed and engine cool, remove radiator cap and observe for coolant flow. Do you see coolant flowing? Yes, see number 5, No water pump not functioning.
4. Fan belt not tight enough causing water pump pulley to slip. Remove belt and verify pump rotates freely by hand.
5. Verify radiator is not clogged internally and the external fins are not plugged with grass/seeds/weeds/mud or anything else that can get sucked into the fins. Some radiators also have protective screens that can prevent proper airflow through radiator.
6. Is the fan installed in the correct direction?
7. I don't like the drop in pressure. Suggest duplicating the test when the thermostat housing leak is fixed. Track over a longer period of time while noting coolant temp. Pressure will decrease as coolant temperature decreases. Once temperature stabilize any drop in pressure is a concern.
Good luck!
Diesel exhaust and gasoline exhaust are not the same. The chemical reagent in the fluid must be diesel exhaust reactive.
Radiator not working, if it were dumping heat into air there would be a temperature difference.
Normal operating coolant temperature should be about 180 degree F.
Should take radiator and disconnect it to do a flow test. Will it let water move through core? If plastic tanks then cannot rod it. Might be able to chemically get obstructions out, maybe.
From cold start with radiator cap off, should be able to see thermostat open by indication of flow at top of radiator. Or very briefly bypass radiator with large clear tubing element, to check flow with water pump.
Bubbles can also be caused by air pockets when changing coolant.
So I got in some of my parts and had a little time today. Bottom line is I put on a new fan belt and radiator cap and without a thermostat and straight well water (I know bad idea) after almost 30 minutes of shredding the temperature gauge was barely half.
My idea moving forward is to do another flush to hopefully stop any corrosion. Take out the radiator and thermostat housing, pour distilled water through the radiator and block and then install the new thermostat. Put everything back together and fill with distilled water and coolant. Also will do a oil change since itÂ’s been awhile. Any thoughts?
My idea moving forward is to do another flush to hopefully stop any corrosion. Take out the radiator and thermostat housing, pour distilled water through the radiator and block and then install the new thermostat. Put everything back together and fill with distilled water and coolant. Also will do a oil change since itÂ’s been awhile. Any thoughts?
TG, here's a link to give you some ideas of a non-corrosive radiator flush, used and recommended for Mercedes Benz.
http://dieselgiant.com/mercedes_citrus_flush.htm
http://dieselgiant.com/mercedes_citrus_flush.htm
Will fill y’all in on everything soon but do have a question. Does my M4700 have a drain plug for the coolant? I can’t find any. Always just take off and a bottom hose.
So after everything it looks like it was the fan belt with possible assist from the radiator cap.
One problem I had was I put in the thermostat and gasket. When added the coolant had a leak at the housing so I tried to tighten more and cracked off a piece of the lower housing. Had to JB Weld it back together but works fine now. Shredded over 20 minutes and never even got to half gauge on temperature. Thank you to all who helped.
One problem I had was I put in the thermostat and gasket. When added the coolant had a leak at the housing so I tried to tighten more and cracked off a piece of the lower housing. Had to JB Weld it back together but works fine now. Shredded over 20 minutes and never even got to half gauge on temperature. Thank you to all who helped.
This was a very helpful thread to our Kubota B3030 that has been overheating (bottom of red zone before shutting off to protect the engine) for at least 7 years while mowing 5 acres.
We have been through every scenario listed here, replaced belts, thermostats, anti freeze, flushed, radiator caps, on and on. Still get to the bottom of the red while mowing.
I did the radiator temp test at the top and bottom of the inlet and outlet 216 degrees at top and bottom. now I was just totally puzzled. Water pump? Clogged internal coils?
LONG story short, he has told me so many times that he has used coil cleaner and hosed out the condenser and radiator yearly (another problem we just ignored was AC not working after the tractor warmed up to HIGH in the New England summers).
THE FINAL FIX: Although the condenser and radiator looked great, I decided to do the cleaning myself. I followed the instructions, sprayed the stuff on, waited 10 minutes and hosed off (he said that is what he did, only once each attempt.)
I did it once with the hose and saw a lot of discolored water and grass dust etc. (but visually it looked perfect) So, I did it again but was concerned that I could not get behind the condenser which eats up 3/4 of the radiator area ... so I got out my (2000psi) pressure washer on a 40 degree nozzle and spent a lot of time cleaning front to back and BACK to FORWARD through the shroud and fan fins. Did this for at least 30 minutes using the coil cleaner 3 times.
RESULT: Tractor runs like brand new. Temp gets to a 1/4 of an inch over cold instead of 3/4 into the bottom of the RED and the AC is ICE COLD all day. ;-) Such a simple but elusive fix!!!!
I hope this helps someone else!
We have been through every scenario listed here, replaced belts, thermostats, anti freeze, flushed, radiator caps, on and on. Still get to the bottom of the red while mowing.
I did the radiator temp test at the top and bottom of the inlet and outlet 216 degrees at top and bottom. now I was just totally puzzled. Water pump? Clogged internal coils?
LONG story short, he has told me so many times that he has used coil cleaner and hosed out the condenser and radiator yearly (another problem we just ignored was AC not working after the tractor warmed up to HIGH in the New England summers).
THE FINAL FIX: Although the condenser and radiator looked great, I decided to do the cleaning myself. I followed the instructions, sprayed the stuff on, waited 10 minutes and hosed off (he said that is what he did, only once each attempt.)
I did it once with the hose and saw a lot of discolored water and grass dust etc. (but visually it looked perfect) So, I did it again but was concerned that I could not get behind the condenser which eats up 3/4 of the radiator area ... so I got out my (2000psi) pressure washer on a 40 degree nozzle and spent a lot of time cleaning front to back and BACK to FORWARD through the shroud and fan fins. Did this for at least 30 minutes using the coil cleaner 3 times.
RESULT: Tractor runs like brand new. Temp gets to a 1/4 of an inch over cold instead of 3/4 into the bottom of the RED and the AC is ICE COLD all day. ;-) Such a simple but elusive fix!!!!
I hope this helps someone else!