Hey, my 330D excavator is overheating hydraulic and engine. I checked bypass valve. The slow return check valve is little bit damaged on its extremities but can move freely indside. Could that lead to the overheating problem if any leak occurs ?. Noting that the bypass valve is still good. And noting that at speed 10 the excavator when I raise the boom up and I keep the joystick on its postion the engine will go from 1950 rpm to 1550 rpm then go up to 1750 rpm. Power shift and negative flow are well calibrated. And at lower speeds performance isn't so good but can be operated. Fan speed is good.
How do you know that your fan speed is good?
Sound is good and suction is good. And rpm monitored with a tachometer
The problem is also that the engine is losing speed when we apply load.
When the engine slows down, is it smoking? If you're convinced that the NFC is good and the P/S is properly calibrated, you need to be looking at a fault in the pump regulator (unlikely) or someone has been tampering with the horsepower screws (more likely). And... ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓
No it s not smoking. I first though about the regulators!. Horsepower screws are on the pump regulators right? They are used to adjust nfc also right? Tell me more about that. S/n t2y00397
Where are the horsepower screws located?
OK, to answer your question. On the pump regulators there are two hex adjuster screws stacked on top of each other. These are the two stage horsepower adjustment screws. To the side of these is a smaller adjuster screw. This regulates the NFC. But let's back track a little; When you're diagnosing overheating in a piece of machinery, you first have to ask the fundamental question 'Is the machine putting out more heat than the cooling system can disperse or is the cooling system not dispersing a normal amount of heat properly?' You say the engine isn't smoking when it slows down (comes under load). That's a classic sign of underfuelling. But at the same time, you're getting overheating. These two facts together don't make sense. I would say that you've either got two problems at once, ie low engine power & a cooling system problem OR you're misreading some of the symptoms.
The horsepower screws are same as those who regulates output flow of the pump?? Anw is there a way to calibrate horsepower screws? My problem I guess is from calibration so the pump is producing more heat than it is supposed to produce. And the performance of the engine is low Cz it's affected by the pump the pump requesting more power than the engine could deliver So it's also overheating. That's my analysis for the problem that I am facing.
And I also calibrated the main relief valve so the Max pressure is around 36000kpa
Yes, the HP screws regulate the flow of the pump, AT A CERTAIN PRESSURE, and AT A CERTAIN RPM. Yes, you can calibrate the hp settings but you need a flowmeter, and pressure gauge, and a tachometer, and the information to make the ECM provide a fixed powershift pressure. It's a non trivial operation. What makes you think that the pumps are demanding more power than the engine can produce?
Because when I increase the load too much. The engines turns off. Noting that power shift and negative flow are well calibrated. Remain the hp screws. Any ideas on how to calibrate them noting that I don't have a flow meter. Should I increase or decrease the flow?
I don't see where you ever checked the radiator and hydraulic oil cooler for plugged up fins. An infrared thermometer will give you a good indication of how well that is working. Check the inlet temp at the water pump against the outlet temp at the thermostat and post what the difference is. As Cmark says above, what you are describing doesn't make much sense.
My excavator only overheats when I apply load. And I calibrated negative flow and and power shift pressure. But its performance still not good.
Is the engine speed sensor on the flywheel clean and reading correctly? That one is for the machine ecm.
The problem was from my pressure gauge... Now everything is fine. I just want to know how much the temperature difference should be between the inlet and outlet of the oil cooler. I got a 10 degrees Celsius different that would be enough ? Ambient temperature is around 40 noon here
A cooler in good condition will give a temperature change of up to 10 degrees C (18 degrees F), so yours would appear to be bang on the money.
And btw my engine is consuming more diesel than it should. And I still have problem with overhearing hydraulic and engine. Calibrations are ok. And oil cooler and radiator are ok. Bypass valve is new. Main relief valves well valibrated. Fan speed correct. Water pump new. Water temperature regulator new. What shall I do?