2240 Overheating

[Peter White]

I have a 1976 2240 that just started overheating under what seems to be normal use (brush-hogging).
I'm thinking either thermostat or water pump but not sure how to determine which is faulting.. Or other cause....

 

[Bob]

Have you THOROUGHLY cleaned the radiator fins of debris and check the fan belt?

Next thing is to replace the thermostat.

It is RARE (but DOES happen once in a while) for a waterpump to fail to pump water. This CAN happen if the coolant is really nasty, and has eaten off the impellor.

Also, IIRC that engine sometimes develops cylinder sleeve pitting.

Any moisture or milky oil foam on the dipstick or oil fill cap?

 

[buickanddeere]

New fan belt properly tensioned. Once an old belt gets glazed they slip unless they are so tight the bearings are being damaged.

 

[buickanddeere]

Note Bob said replace the thermostat, not remove the thermostat.
Its a shock to most but the stat is really in there for a reason.

 

[dieseldoc]

Dont remove thermostat it will actually run cooler with one in.Water pumps rarely fail completely but check pulley to make sure its not wore out.

 

[Leland]

try washing out the raditor with a hose or blow it out with compressed air , be careful if using a pressure washer so you don't bend the fins and block airflow going thru core ,I had to do it several times a year when mowing water ways all the dust and trash just gets sucked right in there from the fan and blocks things up fast .

 

[John Heine]

Are adding any coolant?Does oil look milky? I would run a check to see if there is hole in cylinder liner.Engines that have sleeves need to have coolant addtive to stop cavitation on the sleeve.John Deere tells you that you use JD coolant conditioner.I have seen this problem before.First water pump is replaced never the problem.When the sleeve is the problem first thing it overheats the hole is so small you will not see anything in the oil.

 

[Peter White]

Haven''t been adding any coolant.... with the exception of the last time it boiled over..... oil looks clean, replaced 10 hours ago and still looks good, no milky look to it.....

How do you run a check to see if there is a hole in the sleeve ?

 

[John Heine]

Several different ways to check for cavitation errosion on sleeve.You could drain engine oil fill radiator with water put radiator tester on radiator put pressure let it set see if you get water in pan.I worked for John Deere industrial dealer for 21 years we used lots that type of engine.They made them 3-4-6 cylinder.The way I checked for this problem and I thought this way a easier way.Remove injectors from cylinder head.Remove rocker arm shaft so valves stay closed.Fill radiator up into neck leave cap off.Use rubber tip on blow gun put air into injector hole watch to see if you get bubbling in radiator.BE CAREFULL KEEP HANDS OUT OF FAN AND BELT.WHEN YOU PUT AIR IN CYLINDER THAT PISTON WILL GO TO BOTTOM OF LINER AND WILL TURN ENGINE.JD used many of these engines in industrial equipment this way very common problem.Another way is to remove oil pan fill radiator with water put radiator tester on pressurize system get a light and look where sleeve comes out of block.If you do have this problem youshould replace all the cylinders they will all have damage on them.

 

[John Heine]

One thing I forgot to tell UNHOOK BATTERY