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CAT 299D Fuel leakage code...

HitachiEX

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May 11, 2022
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@Makers Acres Im getting the same fault code (1239-1) on a Hitachi Zx140w, Works ok in Economy mode but won’t last more than 10 minutes on power model, Only happens when the fuel temperature reaches 86°c which seems very hot to me compared to our zx210 that runs around 45°c all day, have changed injectors ,SCV on the fuel pump, rail over pressure valve, going to try replace the high pressure fuel pump next and see is there a difference
 

Makers Acres

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The usual replacement sequence, by doing the cheapest first in order of expense, goes - rail pressure relief valve (or complete rail if valve is not sold separately), injectors, then lastly HP pump.
I was told the valve is a complete package with the Rail now and is around 2K, which is ridiculous!

@Nige What are the side effects if I just install new injectors and don't update the injector code in the engine ECU?
 

Nige

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@Nige What are the side effects if I just install new injectors and don't update the injector code in the engine ECU?
It will run, just not at optimum 100%.
I was told the valve is a complete package with the Rail now and is around 2K, which is ridiculous!
Perfectly illustrates the amount of coin a bit of preventive maintenance can save doesn't it.?
 

Makers Acres

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Absolutely!

Good to know. Still trying to find a solution to installing injector trim codes. I might have the injectors back before I can figure out a solution for that.
 

EarthWorks88

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Oct 16, 2020
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I just solved this issue on our 259d3 that originally had this fuel leakage code this morning, but then changed to 157-4 (rail pressure voltage below normal) when I unplugged and plugged back in the rail pressure sensor connector and could not get the original fuel leakage code to pop back up, even though the operator said he could not go 20 feet before the fuel leakage code would come on. When I first got to the machine, before unplugging the sensor the fuel leakage code would pop up for me at half throttle still in park. My issue was the signal wire at the rail pressure sensor was making a poor connection in the connector. I was getting sporadic voltage readings on the signal wire when back probing while plugged in even though I could find no issues with wire integrity or voltages unplugged. Finally decided to de-pin the connector and found the signal wire spade connection was very loose compared to the ground and 5V. I squeezed the harness side connector that goes to the sensor pin and taped the signal wire to prevent the other 2 from touching and just plugged the bare wires back in the sensor and it started hauling ass around the job and finished a regen. Not sure if this may be your issue, but may be worth checking out.
 

Makers Acres

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I just solved this issue on our 259d3 that originally had this fuel leakage code this morning, but then changed to 157-4 (rail pressure voltage below normal) when I unplugged and plugged back in the rail pressure sensor connector and could not get the original fuel leakage code to pop back up, even though the operator said he could not go 20 feet before the fuel leakage code would come on. When I first got to the machine, before unplugging the sensor the fuel leakage code would pop up for me at half throttle still in park. My issue was the signal wire at the rail pressure sensor was making a poor connection in the connector. I was getting sporadic voltage readings on the signal wire when back probing while plugged in even though I could find no issues with wire integrity or voltages unplugged. Finally decided to de-pin the connector and found the signal wire spade connection was very loose compared to the ground and 5V. I squeezed the harness side connector that goes to the sensor pin and taped the signal wire to prevent the other 2 from touching and just plugged the bare wires back in the sensor and it started hauling ass around the job and finished a regen. Not sure if this may be your issue, but may be worth checking out.
That is great info! I did play around with those wires for a while but never went as far as you did. For some reason the original wire harness was pulling on those wires pretty hard and I had to cut back some zip ties and untaped things until they were no longer stressing the wires.
When I unplug the sensor I get faults right away in the CAT with different error codes. I tried wiggling the wires and stressing them when running the engine and was never able to get that to trigger the code.

I have also noticed fuel getting into my engine oil, so I do think something is physically wrong. When I found out that the injectors are bathed in oil, I was going to just trying pulling the injectors and swapping all the o-rings. I slept on it and thought that because I had them out and due to the difficulty to remove them, I decided to send them off for testing.

I just got the tests back and 2 out of the 4 injectors did fail the tests. One was over performing and one was underperforming is what I was told. I will get the full report once then injectors get back to me. Apparently Kubota does not allow these injectors to be rebuild in the US, so no injector house will take a stab at rebuilding them.

I ordered two more, but still uncertain where the fuel getting into the oil.
 

ozarkag

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Fuel in oil has 2 main options, one is fuel return lines from injectors, the little banjo bolts and copper washers. Especially if you, ( or someone) had injectors out before.
2 is High Pressure fuel pump shaft seal can leak. The injectors themselves, AFAIK, cannot leak fuel into oil. Any fuel in oil is a cause for concern, not only is oil being diluted, but I have seen more than one overfill to the point oil is pushed thru the turbo, resulting in uncontrolled runaway.
 

Makers Acres

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Fuel in oil has 2 main options, one is fuel return lines from injectors, the little banjo bolts and copper washers. Especially if you, ( or someone) had injectors out before.
2 is High Pressure fuel pump shaft seal can leak. The injectors themselves, AFAIK, cannot leak fuel into oil. Any fuel in oil is a cause for concern, not only is oil being diluted, but I have seen more than one overfill to the point oil is pushed thru the turbo, resulting in uncontrolled runaway.

I ordered all new Banjo bolts, washers, seals, and a new return line since I have it all apart anyways.

I think you are right, but the CAT service guy I spoke to said that there is a chance due to the way these injectors are bathed in oil. I am guessing that fuel could get pushed back during the compression stroke if that copper washer is not seated properly.
 

Makers Acres

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I am going to post some CAT troubleshooting about Fuel in the oil...

Probable Causes:
1. Oil Change IntervalThe oil should be changed at 500 hours.

Perform oil sampling to ensure that fuel dilution is not flagged prior to the next 500-hour oil change interval.
2. DPF Nearing 3000 Hour Maintenance IntervalInspect DPF for plugging.

A. Establish communication with Caterpillar Electronic

Troubleshoot the diagnostic code 523602-0 High

Frequency Regeneration code is active can cause fuel dilution. If this code is present refer to “Diesel Particulate

Filter Active Regeneration Occurrence is Excessive”.
3. Low Load ApplicationFuel dilution can occur in low load applications.

Refer to Special Instruction, REHS3007 , Duty Cycle of Machine Applications Requires a Reduced Oil Change Interval. In addition low load applications can result in more frequent active regenerations which can also cause fuel dilution.
4. Leaking SealsA. Remove the injector from the affected cylinder and visually inspect the injector O-ring seals for damage.

If leakage is found and the O-rings are in good repair, there may be a problem with the injector. Replace the injector. Ensure that the new trim codes are installed.

Refer to Troubleshooting, "Injector Trim File - Install" for details.

If the leakage is not located, add the appropriate dye to the fuel tanks. Run the engine at high idle for several minutes. Shut down the engine and remove the valve covers. Use a black light to check for traces of dye around each injector.

If 523602-0 Exhaust Gas Temperature : High Most
Severe (3) code is present, it may cause fuel dilution.

Troubleshoot the root cause of the code first.
5. Fuel Injector TipA. Use Cat ET to perform the "Cylinder Cutout Test" to identify any cylinders that may be over fueled.

B. A fuel injector tip that is broken or fractured is a possible cause of a cylinder that is being over fueled. If a cylinder is identified by the test, Remove the injector and check the injector tip for damage. Check the fuel injector tip for cracks or breakage.
6. Leakage of Fuel Return LineA. Check for fuel leakage of the fuel return line under the valve cover.
7. Cracked Cylinder HeadA. Look for signs of damage to the internal passages for the fuel supply to the injectors in the cylinder head.

Check for pin hole leaks. Refer to Disassembly and Assembly.

This is my plan of attack.

Step 1, Replace all 4 injectors! Thanks @Nige for persuading me into this.

Here is how I am addressing the above table:

Number 1: It has been 2.5 years since I changed the oil, but I only have 145 hours on the oil itself. I am going to change it after the injector replacement.

Number 2: I don't think this applies to me, and I can't really check without the computer.

Number 3: This 100 percent applies to me and I think this might be one of the real culprits. I have been running this machine the last 3 years at low load and less then 1800 RPM because of the Fuel Leak Code.

Number 4: I will be replacing all seals including rubber, copper and other metal washers with the new injectors.

Number 5: New Injectors also addresses this issue.

Number 6: I am replacing this line and all seals that are associated with this.

Number 7. Let's hope not! The fuel return line is the only thing that goes through the head and it looks like only a very small pathway, maybe an inch or so long. This would be very bad luck if somehow this cracked.

I should have new injectors by mid next week, and I will post my results after the install.
 

Nige

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Number 1: It has been 2.5 years since I changed the oil, but I only have 145 hours on the oil itself. I am going to change it after the injector replacement.
FYI, from the O&M Manual for your GTC-prefixz machine if it is not accumulating a large number of hours the following recommendations apply.......

"The following guidelines should be followed if the service hours are not met:

1. Items listed between 10 and 100 service hours should be performed at least every 3 months.
2. Items listed between 250 and 500 service hours should be performed at least every 6 months.
3. Items listed between 1000 service hours and 2500 service hours should be performed at least every year."


Back to that dirty word Maintenance again........
 

Nige

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the original paperback manual that came with it.
My quote above came from the latest online iteration (Dash 25 updated May 2024) of the Operation & Maintenance Manual. If your paper O&M Manual is an earlier version the text it contains with these recommendations may differ. Here's another snippet for you. Again if you don't have the latest version the text may differ somewhat......

The normal oil change interval for the machine is Every 500 Service Hours or every one year provided that all the following conditions are met:
  • An engine oil in the Operation and Maintenance Manual, "Lubricant Viscosities" is used.
  • Cat filters are used.
  • The altitude does not exceed 2300 m (7545 ft).
An oil change interval of Every 250 Service Hours or every 6 months is required when any of the following conditions occur:
  • Not using a recommended engine oil in the Operation and Maintenance Manual, "Lubricant Viscosities".
  • Cat filters are not used.
  • The altitude exceeds 2300 m (7545 ft).
 

Makers Acres

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My quote above came from the latest online iteration (Dash 25 updated May 2024) of the Operation & Maintenance Manual. If your paper O&M Manual is an earlier version the text it contains with these recommendations may differ. Here's another snippet for you. Again if you don't have the latest version the text may differ somewhat......

The normal oil change interval for the machine is Every 500 Service Hours or every one year provided that all the following conditions are met:
  • An engine oil in the Operation and Maintenance Manual, "Lubricant Viscosities" is used.
  • Cat filters are used.
  • The altitude does not exceed 2300 m (7545 ft).
An oil change interval of Every 250 Service Hours or every 6 months is required when any of the following conditions occur:
  • Not using a recommended engine oil in the Operation and Maintenance Manual, "Lubricant Viscosities".
  • Cat filters are not used.
  • The altitude exceeds 2300 m (7545 ft).
Thank you! I do use all CAT products and recommended viscosities since I am in a warm climate and don't need to worry about those cold starting temps.
 

ozarkag

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Good info. We have started recommending oil change intervals of 250 to 300 hrs on all small diesels with 500 hrs book itervals. I have seen total bearing failure at 700 hrs on an oil change. . . . It's just not worth it, oil is cheap. And we do use Mobil 1300, which advertises extended change intervals.

One thought on #7 on your list, supply to the injectors is not thru the head, however the connection to the Injector is under the valve cover. A high pressure leak will put a significant amount of fuel in oil.
 

Makers Acres

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Good info. We have started recommending oil change intervals of 250 to 300 hrs on all small diesels with 500 hrs book itervals. I have seen total bearing failure at 700 hrs on an oil change. . . . It's just not worth it, oil is cheap. And we do use Mobil 1300, which advertises extended change intervals.

One thought on #7 on your list, supply to the injectors is not thru the head, however the connection to the Injector is under the valve cover. A high pressure leak will put a significant amount of fuel in oil.
I normally only go about 150 hours on my oil changes, but that normally takes me 2-3 years to get to that point.

For number 7, in the manual it was specifically related to the return line that only passes through about 1 inch of the corner of the cylinder head. This would really suck if something there was cracked.

I am replacing everything else related to the fuel return lines and the new bushings and o-rings on the high pressure side just to make sure that gets ruled out.
 

Nige

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We have started recommending oil change intervals of 250 to 300 hrs on all small diesels with 500 hrs book itervals. I have seen total bearing failure at 700 hrs on an oil change. . . . It's just not worth it, oil is cheap. And we do use Mobil 1300, which advertises extended change intervals.
500-hour oil changes were only ever introduced as something of a sales gimmick.

It all started with Sales Department (I'm talking about manufacturer level here, not dealer) constantly badgering Engineering to "reduce the amount of preventive maintenance work required, it's making us look bad compared to the competition". So Engineering did exactly that, and while doing so put a load of caveats into the O&M Manual as to what type(s) of operating conditions would cause the PM schedule to fall outside "standard". Standard in this case being a 500-hour oil change interval. These included: -

Use of lubricants that did not meet the required standard.
Use of non-OEM filters (although personally I have an issue with that one)
High altitude.
Engines operating a very low number of hours per day/week/month, etc.
Engines operating at low load factors.

The big problem in all this is that generally the customer doesn't read the caveats. Or if they do read them the logic behind the caveats doesn't sink in. All they see is "500-hour oil changes" and thats it.

In my work I never ran into this because our machines were generally clocking 500+ hours per month on average. On the other side of the coin I spent a lot of time working in the Andes and believe me trying to convince customers that the fact they were operating at 8,000+ft above sea level required them to reduce oil change frequency from 500 to 250 hours was a very hard sell. Eventually after a lot of badgering by the affected dealers Cat even produced a Special Instruction regarding operating engines at high altitude which made the job of convincing them somewhat easier.
 
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