I have a 320D Excavator Serial Prefix - FAL and it overheats every time 1hour into the job. I have managed to change fan assembly, clean radiator cores, replaced radiator cap, drained and replaced coolant, changed water pump, changed thermostat but the problem still exists. Every 3hrs of operation I have to top up engine coolant because coolant leaks off overflow hose at the radiator cap. When I remove radiator and start up engine (from cold start) the coolant rushes out of the radiator cap. More coolant rushes out of the radiator cap when the engine RPM is increased. I suspected combustion leaks so I did carried out a combustion leak test but test dye did not change color due (no combustion in the cooling system) but I did noticed a lot of air coming out of the cooling system. I do not have the AC running (AC belt removed). Where could I possibly have a air leak into the cooling system? PS, I am waiting on parts to replace head gasket.
I just dealt with a 330d that had speed sensor issues and wasn't kicking the hydraulic fan into the second speed, replaced sensor and calibrated fan and its all good
Thank you for this information. I will have a look into this.
It's highly likely that your radiator coolant flow is reduced. The radiator cells may be clogged at the top or bottom. Also, inspect the lower hose that runs from the bottom of the radiator to the water pump. Check it at full engine speed to see if it's pinched. Does the hose compress at maximum engine speed?
I just checked. There is no clogged in the radiator and bottom hose is not kinked at high RPM.
I'm talking about internal clogging of the radiator cells. You can check this with a pyrometer, looking at the temperature difference between the upper and lower sections of the radiator. We once checked with an endoscope, and all the lower cells inside the radiator were clogged with some kind of fine sand. Before that, the excavator was sinking in murky water.
This one it is fine because we recently removed and had it pressure cleaned (inside) top to bottom. Flow is okay.
It's impossible for everything to be perfect—no gas leaks, a new pump and thermostat, and a perfect radiator—but it's still overheating. Apparently, you've missed something. Again, you won't be able to see the inside of the radiator, and it will be flushed with water, but the honeycombs may be clogged. To see this, you'll need to remove the trays or use an endoscope to look inside.
Thank you very much for this information. I haven't really checked as mentioned. Looks like I will have to go through with second time inspection to confirm this. Thank you once again. I will keep you posted on results.
Also, your excavator has a viscous fan coupling. If the coupling isn't working properly, the fan speed may be low. Different viscous coupling settings can also be applied via CAT ET. In your case, the ideal way to check this is to simply disconnect the connector to the viscous coupling so the fan always runs at maximum speed.
We had occasional issues on the drill rigs of a similar series 325. There’s a setting for the fan, assuming it’s capable of achieving desired rpm, called tropical I think. More fan speed. The monitor should show you desired fan speed (as called for by ECM) and actual. When they’re running at full clip they’re quite loud. There was also an update for certain series with a different viscous fan which would change the routing of the wiring, that’s how I was always able to tell if a machine had the update or not.
Can you post a machine Serial Number so that we can take a look how it was originally built, especially whether or not it was equipped with a tropical fan setting.
If you think you're getting combustion gasses in your cooling system, run it with your cooling system pressure tester installed and see if the pressure rises. If you have a failed head gasket the pressure will climb and wont stop.
My CAT 320C had a blown head gasket earlier this year. One of the symptoms was that I could hear bubbling at the coolant reservoir and see where it was overflowing. It is detailed in this thread: HeavyEquipmentForums
The Gregybwoy wrote that he tested for combustion leaks in the cooling system. And the test showed no gases in the system. The question now is, did he do the test correctly?