Cat 320C (year 2003) lugging down and overheating

[rockfall]

Hi guyz,

I also have an overheating problem with my Cat 320C. I spend a lot on this machine every summer. Had radiator and hydraulic cooler cleaned. Changed the head gasket, replaced three pulleys and fan as cat agent here suggested to replace it with high ambient pulleys which was last summer. Tried lots of technicians but no use. The machine lugs down especially when I try to work two cylinders at a time.

Actually the lugging started 3 years ago after I drained the old hydraulic from the tank and replaced the injectors. I bleed the fuel lines to the engine cylinders for air but no use. Dont know if its a fuel or hydraulic problem. Also I replaced all the filters and cleaned the banjo fittings in the fuel line. Had the diesel pump also calibrated. In addition, the rpm of the machine changed and is lower than normal after I changed the hydraulic and injectors.

I think that if I fixed the lugging problem the overheating problem will be solved with it.

Any suggestions guyz?

Thanks

 

[Mobiltech]

Did you put in the proper part number cat injectors or did you go with aftermarket or jobber injectors?
What type and viscosity of oil did you put in the hydraulics?

 

[rockfall]

We replaced the nossle had original nossles and we use elf 68 hydraulic

 

[Mobiltech]

Does the engine speed and lug improve as the machine warms up after working a while?
Is the high engine speed with no load lower than it was before the nozzles and oil change.
I have had to set up the high idle speed on some 320 s to get it up to spec.
The hydraulic lug can be adjusted by doing a PRV calibration

 

[rockfall]

The engine speed and lug worsen after 5 or 6 hours of working and even stop most of the times coz it cant bear load. The high engine speed I dont remember coz its been 3 years. How can i set the high idle speed.

 

[Mobiltech]

The high idle speed can be hard to set up because there is a factory lock on the adjustment screw.You can cut the lock but its not easy.
Setting the high idle is not going to fix the stalling problem. You either have a pump control problem or an engine low power problem. I would start with some gauges on the prv or pump regulating valve to see if its working. Maybe do a prv calibration.

 

[rockfall]

Hi Mobiltech,

I will do the prv calibration and come back to you. What do you think about the rpm sensor in the bell housing? Can it be the culprit?

thx

 

[Mobiltech]

You can read the output of the engine speed sensor on the cab monitor if you think it's a problem. The 320 c also uses pressure sensors in the hyd pump make sure they read out on the monitor too.
If you enter the service mode you can see all the outputs. The code to get in should be FFF2.

 

[rockfall]

Mobitech, do you know the required output readings coz I dont have a manual to know the outputs. I just know that the rpm should be around 1950.

I will try to get into the service mode and get you the readings. In addition, can I replace the prv solenoid instead of calibration coz I have never done that.

 

[Mobiltech]

The monitor will read out the actual RPM. Calibrating the prv makes sure the solenoid , the wiring and the ECM are working properly.

 

[rockfall]

Mobitech. The main culprit was the backup switch under the armrest. Replaced it for 50 USD. The PRV Solenoid was off because of this switch. Also found out that it was out of calibration so one of the guys sent me the procedure to calibrate the PRV. Now the machine is working very good and is not lugging down.

Thank you guys.

 

[rockfall]

Just for the readers knowledge this switch made my machine choke and stall under load, overheat and the tracks were very weak.. Now all this is gone and rented my machine again on a 18 hour shift per day ;-)

 

[jey_c]

what about overheating?

 

[rockfall]

Overheating is also gone coz maybe it was working harder than it should

 

[Mountainmover]

What is this backup switch thing that is under the armrest? Is it near the wiring harness that runs up under the door size arm rest?

 

[rockfall]

Yes its under the armrest