Hitachi zx290lc-5 coolant overflow

[kevman6]

I have a zx290lc-5 It runs great, but wouldn't come up to temp unless we blocked part of the radiator. We found no thermostats and replaced them. Now it overflows the reservoir bottle and spits out coolant overflow tube. Then eventually will overheat and shut down. It will run great with one thermostat in it with some cardboard over part of radiator, but always has too much flow into the reservoir bottle. Is there a separate bypass thermostat for the bottle? The fan sucks air through the radiator. I would assume that is the proper direction. The excavator came from a hot climate, and i am assuming thats why the thermostats were taken out. Lots of power, no other problems. Hitachi tech was just out to initialize a regeneration. It wouldn't come up to temp before the cardboard was put in. He said everything seemed OK, but needed thermostats. Any ideas would sure help.

 

[Delmer]

run a hose from the overflow tube into another overflow bottle full of water, see if it bubbles, and builds pressure on the cooling system right away when started cold. or get an exhaust gas test kit. The head gasket may be leaking, or something else may be leaking.

 

[rondig]

Also check rad cap....had that problem on my 200 deere.

 

[kevman6]

Have a technician coming out this morning, it's doing crazy things. Warms up to temp, and then when the thermostats
open up and i raise the RPM, it drops the temp down to the zero mark. Coolant is cold to touch as is all the hoses and routing for coolant are cold. Thermostats are correct ones. I cracked the intercooler bleeder bolt open and got some air out, but still wouldn't bring temp back up. If anything, it should be overheating. The tech should be able to tell if the sending unit is failing, but doesn't seem likely because it follows the warm up curve.
The regen request makes me wonder about a possible head gasket leaking into the exhaust, then it might be restricting the element. Still has cavitation in the overflow, however dealer says that is normal.
It makes me wonder what all they do to these in hot climates like Arizona to keep temps down while they work them.

 

[Vetech63]

There needs to be more troubleshooting done. When the temp comes up, verify somehow that the temp at the thermostat outlet is the temp setting of the thermostat. Make sure the thermostats are in correctly as I have run into machines that have had them installed upside down. If your temp at the thermo housing is correct (180-190 or somewhere near there) if your water flow from the water pump is good the temp at the top of your radiator should be the same. If you have good airflow through your radiator, you should have around a 30-35 degree drop in temp at the lower radiator hose.
It sounds to me like you could have 2 different issues possibly. If you top the radiator off with antifreeze and put your overflow bottle on the full mark (before you start the engine) the system should work at this full capacity. If you are still losing fluid out the overflow tank, I would check the radiator cap first. You could possibly have a gasket leak at the head, but I would think that would show up regardless of the cardboard or not. Its possible that your temp sender is faulty, but it shouldn't cause the overflow tank to spill over. A faulty temp sender can cause the engine ECU to slow or stop your engine.
General rule of thumb is...…….the thermostats regulate the temp and the speed of the water going through your radiator. The water only absorbs the heat of the engine, the airflow through the radiator is what cools the water.
Also, Im not sure what type of fan drive system your machine has but recently I had a JD loader that wouldnt heat the cab. When you started the machine, the fan sounded like a helicopter taking off. The machine had a problem with the electrical part of the fan drive and it was in full drive all the time throughout the engine rpms. You couldn't run that machine hard enough on a cold day for the engine to ever heat up. Its worth checking into also if you have that kind of system.

 

[kevman6]

Service rep came out and confirmed my suspensions. We checked thermostat orientation and topped of radiator and bled system before starting engine. immediate pressure into overflow bottle with new cap. Being picked up today and sent to dealer for head gasket (I Hope nothing else). I would normally do it myself, however outside in 20 deg temps is a big NO.

 

[garyw]

I'm assuming its a 4HK1 engine that's fitted to the machine? I would like to think that the EGR coolers have been checked on the machine? I've seen many a customer go down the route of removing the head and it turns out to be a leaking EGR cooler. These are very prone to fail if not bled properly and also exhibit all the similar symptoms of a head failure.
Also, i have seen a few engines with head bolts broken on the rear of the engine causing the obvious head gasket issues.