1538 HST error light with over temp, help

metalcaster · Sep 5, 2015

Big weekend with big projects planned and now the 1538 has an error light flashing. Engine temperature rises after a few minutes of running as if the thermostat is not opening up. 81 hours on the tractor. The manual does not help much and the only folks at the dealer today were the parts counter guys not very familiar with the tractor. They suggested I bring it in on Tuesday to get it checked. It ran fine yesterday for the 45 minutes or so that I ran it. Can anyone offer any suggestions? I'm thinking about draining the coolant down and checking the thermostat, presuming that it is under the cast elbow like almost every other engine in the world.
Here is the light that is flashing:

jjlite · Sep 5, 2015

Not sure if this helps but I brush hogged for a few hours and had to clean the screen over the radiator also blew the radiator out it was pretty bad.

metalcaster · Sep 5, 2015

jjlite said:
Not sure if this helps but I brush hogged for a few hours and had to clean the screen over the radiator also blew the radiator out it was pretty bad.

It's clean, gonna try popping the thermostat elbow off.

AchingBack · Sep 5, 2015

Is the engine temperature really rising or is the sending unit defective? I'd try using an external temp. gauge before taking things apart. Your problem is one reason among many I am thankful for owning a tractor without too much modern technology. I hope it is something simple; a loose wire connection, etc..

metalcaster · Sep 5, 2015

So I pulled the elbow off over the top of the thermostat after draining a gallon or so of coolant. Moved the valve on the thermostat down a few times with a screwdriver, it might have been a little sticky at first. It sprung back closed each time. Buttoned it back up and refilled the radiator. Started it up with no error code and the temp gauge stayed down on the C peg as it normally does. Ran it for about 30 minutes without any issues. Thank you Jesus I can get back to the projects planned.

AchingBack · Sep 6, 2015

metalcaster said:
So I pulled the elbow off over the top of the thermostat after draining a gallon or so of coolant. Moved the valve on the thermostat down a few times with a screwdriver, it might have been a little sticky at first. It sprung back closed each time. Buttoned it back up and refilled the radiator. Started it up with no error code and the temp gauge stayed down on the C peg as it normally does. Ran it for about 30 minutes without any issues. Thank you Jesus I can get back to the projects planned.

AMEN.

metalcaster · Sep 6, 2015

OK so maybe I shouldn't be planning on working Sunday? Flashing light is back, temp rising. Will try to get a new thermostat this afternoon and replace it.

metalcaster · Sep 7, 2015

New thermostat did not help, ran 10-15 minutes before the light started flashing and the temp gauge started climbing. When I ran it a little on Sunday morning it started blowing white smoke and lost power, all I could do to get it back in front of the barn. I'll get it loaded up and take it in tomorrow.

Uncle Hulka · Sep 7, 2015

I'm not a diesel mechanic, but that sounds like a problem related to the head, like a gasket or possible warped/cracked head to me. This could happen if the engine got really hot, but that doesn't sound like the case here.

Very sorry to hear of your problems. This thread is especially important to me, as I am very close to purchasing my first band new tractor, and it's between either a 1533 or 1538.

Very best of luck to you and please keep us posted!

metalcaster · Sep 9, 2015

So the dealer checked it out and the temperature sending unit was defective and that is what was throwing the code. They changed it out and it will be ready for pick up in the morning. There have been reports of some temperature issues with the 1500 series mostly running cold per the area rep.