jinma 224 temp.

[TSMART]

Although my radiator is full and clean, and the fins have been blown out from the inside, AND theres a blue mesh type AC filter I installed in front of the radiator, the tractor gets hot, though very slowly. Battery location in front of the radiator is stupid IMO, but I am no engineer. I wonder just how much cooling that robs me of.

All winter long the temp gage stays around 80, but today in florida where I am using the finish mower, it was like 95 degrees. I try to keep the bucket up a little to increase air to the engine.

But when the weather is this hot, the temp gage slowly (within 2 hours) gets up just to short of the red zone, thats when I drop the RPMS for a while and shut her down. Happens very typically when its this hot, humid. 90 plus. Unfortunately, thats when the grass grows!

I have seen mods where folks poke holes in the cowl (hood) to get increase air flow, maybe I should do that, (would it make a big difference??) but what about changing thermostat when its very hot outside. Is it gonna be a wierd chinese thermostat??? or impossible for me to do??

 

[Walter L]

I think i would first make sure the temp gauge is correct, then have a look at this info, its not on the tractor but is on a diesel engine.
http://pages.prodigy.net/jforgione/MB_WW.html\
If the temp is correct and this dont help then I would think about moving the battery.

Walt

 

[zogman]

How is your water level? Are you finding that you are slowly blowing water out the overflow tube? My Kama is losing water and slowly getting hot and after some expert advice on this forum I believe my problem is the head gasket leaking very slightly pressurizing the radiator. I tried to do a head retorque at 50 hrs but could not get the head bolts out. I am going to try again with my impact gun this weekend.

 

[TSMART]

I checked the level in the radiator, it was about a quart down. So I filled it up completely.

Went to work with the tractor (again, 94 degrees here today) and same thing, in about 2 hours, it heats up. ..no difference at all....(I never have let it go into the red). But I am pretty sure it would creep into the red if I let it go another half hour.

Again, I would like to ask if another thermostat would work better in these hot conditions.

Another thing I don't quite understand...manual says after you work it for a while, drop your RPMS for about 5 minutes before you shut her down.

When I drop RPMs, the fan turns more slowly, right? Less coolant is pumped through the engine, right? So if I drop the RPMS for 5 minutes after working, I would think that would only help to overheat. So I have to wonder why that shut down procedure is recommended. ?????

FYI my JM224 has 140 hours on it.

 

[3RRL]

Just a guess, but more than likely the heat generated from compression and detonation at high rps is 10x what it is at idle? The cooling passages in your engine are only so big and allows x amount of coolant in there regardless of how fast it is flowing. The coolant has to dissipate the heat generated. Yes, the coolant flow is slower, but there is about the same amount of coolant in the passages so the heat is better dissipated and the engine cools down. At least that's what I think...
Mine cools down when I idle it after a high rpm workout.

 

[RonMar]

You want to let idle to dissipate the heat better. As 3RRL mentioned, much less fuel being burnt and less heat being put into the engine, but still the same volume of water so it carries it away better. If you shutdown right after a hard workout, without water flow, the water next to the cylinder liners can boil because it is not being replaced by fresh water from the lower radiator hose/waterpump. The oil up in the cylinder head and down in the bearing surfaces can cook as the high cobustion heat leeches out into the engine. Pretty common to see overheated autos boil over right after shutdown. No more water flow to transfer the heat to the radiator so it boils in the engine, overpressurizes the system and the pressure cap opens to vent the pressure. Engines with turbochargers need this cooldown time even more. The oil will cook in the turbo bearings if the manifold isn't allowed to send as much of it's heat as possible on down the exhaust pipe till it is at the lowest temp possible before shutdown. High speed bearings don't like carbon buildup

 

[TSMART]

Thanks for the explanation. It makes sense.

Now, any ideas about what to do about the slowly rising temp? Are these tractors just not designed to work in the heat?

Again, this same thing happened last summer. Never during the cooler months here in central Florida. Either find a way to increase airflow? Or anything to help to keep the heat down?

I keep the engine very clean. I always run in the green zone (rpms) Don't know what else to do. Hood scoop?? extra Fan rig job??? Many times I need to be on the tractor MORE than 2 hours....I even removed the hood side peices to get more air.....just want to treat it right. Love my tractor. thanks.!...

 

[RonMar]

Have you actually placed a light down behind the radiator and looked thru the passages? All of them? A small automotive light bulb with wires soldered on and taped to a stick works well for this to get it to all the rear face of the radiator, powered from the battery. You could have a few that are not quite all the way open.

What you describe sounds like a system that is just a little bit shy of being able to remove all the BTU's generated by the engine under load. How big is the mower you are running? Does the mower drivetrain spin freely? You could simply be overloading the engine. Some other things to look at would be:

1. How is the fan placed in the shroud. Too deep or two shallow could allow air to recirc around the blade tips instead of being sucked thru the radiator and being blown back along the engine.
2. How does the shroud fit to the rear of the radiator. Any leaks here will allow air to be drawn in this way instead of thru the cooling fins where it needs to go.
3. Is the fan belt the proper tension? if it was a little loose, it could be slipping slightly and lowering both the air and water flow.
4. Have you replaced the thermostat? Remember where these parts came from. It could be that the thermostat initially opens correctly, but after continual heat soak the bi-metal actuator looses the battle to stay open with the spring. Does the temp come down when you take the load off the engine(disengage PTO, keep RPM's on the engine)?
5. Removing side panels was good to improve airflow. How much air do you think can recirc around the sides and top of the radiator, between radiator and hood sides/top? You should try and restrict as much of this as possible with blocks of foam.
6. Where is the air intake/air filter for the engine located. Drawing from hot underhood air could increase internal engine heat slightly. The lower air density would also lower HP which would force the governor to burn more fuel(more heat) to compensate and maintain RPM under load.
7. Injector timing off = lower HP and more throttle to maintain engine RPM.
8. Your battery is in front of the radiator? Well all the newer model 200 series moved it down between the frame rails. Changes cost manufacturers money, so I doubt they did it for no reason.
9. Can you see what is comming out of the radiator overflow hose when it gets really hot? If you are getting a lot of stuff comming out that hose, you could have a headgasket problem that is injecting combustion gasses into the cooling system. This pressure will build and vent thru the radiator cap/overflow hose. The hot gasses will also find their way to the temp sensor and make the gauges seem like the engine is running hot. A radiator overflow catch can/expansion tank is good for this as the combustion gas is a little dirty and the carbon and oil it carries with it will collect in the catch tank as dirty brown/black foam. A catch can is also a good idea to keep the radiator full of fluid and from dumping coolant on the ground every time you run the tractor.

As suggested, calibrate/confirm the temp gauge reading. An infared thermometer is good for this.
Change out the thermostat, or at least verify it's full open/proper operation with a thermometer in a pan of hot water. Does the engine oil pressure drop off with the temperature increase? This is also a sign of overheating. There is probably a domestic equivelant for your thermostat, but I don't have the number. Use the search function, I know this subject has come up before in the chinese forum. Inspection or replacement is pretty easy to do and should only require a gasket at most. A few of the other areas for improvement are all documented over on Johns Jinma site. JinmaInfo2

Good Luck

 

[Wayne_Freeman]

You may have already checked this and if so disregard. Open the radiator cap and run the engine. If there is any bubbles(at all) you have a head gasket leak and it is pushing fluid out slowly. This has happened to me twice and will exhibit you symptoms. If that is the case you will need to pull the head and replace the gasket.

 

[Affordable]

We have the battery boxs that go on the newer Jinmas which lowers the battery down so it's not in front of the radiator,I have been wanting to relocate one to see if it will work and how much modification would have to be done if any,but I have not got one of the old styles in the shop for service to check it. .It bolts on where the front suitcase weghts normaly mount
If you want to call me with some measurements we can see if it will work or e-mail me some pics of the front of your tractor and side shots will help alot maybe we can lower the battery out of the way

Tommy
Affordable Tractor Sales
tommy@affordabletractorsalesco.com
979-865-4002