2009 Hino 268 Frequent Regen

johnpham · Jan 17, 2017

I'm facing a 09 Hino 268, J08E engine with frequent regen, the last interval between regen was 64 miles.
Previous work done was replaced turbo, and cleaned DPR.

The driver report that the DPR bar went from 1 to 2 then jumped straight to 10 then he has to do a regen.
took a look at the differential pressure reading was 16 kPa at most. Differential Pressure Standard value should be at 23.0.

Question is am i facing a clogged DPR or is it some thing having to do with the temp sensors?

johnpham · Jan 17, 2017

Did a wiggle test on both TEMP sensors and they seem to be ok.

greasytshirt · Jan 17, 2017

johnpham said:
Did a wiggle test on both TEMP sensors and they seem to be ok.

This 'DPR graph jumping' has a few distinct causes. Often, the temp sensors on the inlet and outlet of the DPF are at fault. These sensors ought to be replaced every 200-250k or so. Just about as often is the wiring harness to the sensor within an inch or two of the connector. There's something about the way the harness is shaped, it will vibrate right at that spot. Eventually the wires break inside. This area also gets hotter than hell, so insulation and stuff suffers. You can electrically load test this whole circuit, but have the ignition off and remove EVERY connector at the ecu if you attempt to do so.

So you put a turbo on it? Did the old one pass a bunch of slimy tarry goo into the CAC? They often do, and it might not be that noticeable. You need to clean out the CAC. Either have it hot-tanked in an aluminum safe cleaner, or fill it with chlorinated brake cleaner and let it soak for a long time, then shake it up and pour it out. Don't use a flammable solvent. If any is inside when the engine is fired up, it'll run away. There are dangers of heating chlorinated solvents too, so please make sure that thing is completely dry before reinstalling it. If there's evidence of the CAC having cracked, replace it. No boost leaks can be tolerated.

Modify the ITV if you haven't already. Replace the air filter. Adjust the valves. Install the crankcase vent filter (and larger cap) from an 2011 and newer truck. All of these steps ensure the engine gets all the oil-free air it can handle, which is important for productive regens at normal intervals.

The last thing that can cause graph jumping is the engine software, but this effects maybe 10% of vehicles.

johnpham · Jan 18, 2017

Turbo replacement was due to lack of power and code p0045 VNT. The turbo itself was in good shape...don't remember if anything passed through the turbo..
I'm new to truck terminology so what is CAC?
I will replace both temp sensors before going further with this..
I will take a look at the IVT to see if it has been modified...I remember see this in the tech tips

Thanks a gain Greasytshirt....

greasytshirt · Jan 18, 2017

johnpham said:
Turbo replacement was due to lack of power and code p0045 VNT. The turbo itself was in good shape...don't remember if anything passed through the turbo..
I'm new to truck terminology so what is CAC?
I will replace both temp sensors before going further with this..
I will take a look at the IVT to see if it has been modified...I remember see this in the tech tips

Thanks a gain Greasytshirt....

CAC is charge air cooler. The intercooler. If in doubt, clean it out.

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