2011 hino 268 p0402 loss of power

roderex

New Recruit
Owner/Operator
Offline
I have a 2011 hino 268 that is having fault code p0402. It’s losing power only going 30 mph and the turbo seems not boosting and i can hear hissing sound from the exhaust and air bogging out from the air filter whenever it losses power. During mornings and night time it runs good plenty of powerr.whenever the weathers warm and im going uphill it losses power.i let the truck sit to cool down for an hour then it’s okay again until the engine gets warm again. So far we replaced the turbo with brand new oem, all the intercooler hoses, maf sensor, fuel filter, fuel water separator, air filter and cleaned/ baked the DPF filter. Still to no avail but that did make the p0299 code go away. I still have the p0402 active. We are out of idea my mechanic advised me to take it to the dealer for a diagnostic. Dealer advised me to change the egr valve, egr temp sensor and egr cooler. Have you seen egr valve go bad on this trucks? It’s pretty pricey. I don’t want to keep throwing parts on the truck and still having the issue afterwards. Please help
 

Hino123

Expert Expediter
Researching
Offline
I have only ever seen one fail…. In the 11 years that valve has been in use. P0402 is for high egr flow. Essentially the engine ecu has an algorithm/ calculation which judges theoretical egr flow and actual egr differ. If these two do not correlate for over 30 seconds it sets the P0402 code. It uses the intake air temp, mass air flow, injection quantity and engine speed to make this calculation. The trouble tree states a possible defective IAT/MAF, injector, engine speed sensor or ecu as, the probable causes. It doesn’t however list the egr temp sensor, egr valve or cooler as a probable cause. I have NEVER seen a 2011-2021 Hino egr cooler fail. If you don’t have a copy of DX2. I would 100% verify there are no obstructions blocking the MAF/IAT sensor. The egr valve will not open until the engine is 104 degrees. I would try to determine at what temperature the code will set. If the charge air cooler is plugged it could cause a P2099 code for underboost. Check it internally with a mirror for clogging and externally for leaks…. Look for oil stains in the corners. If you have a sister truck try swapping sensors. Look closely at the boost pressure sensor hose for clogging or restriction. I personally would not throw a cooler and a valve at it. It sounds like they are best guessing the diagnosis. I would try a boost pressure sensor, MAF/IAT sensor and a Egr temp sensor before any of that other stuff they recommended. Check that charge air as well. A restriction in the exhaust could also cause that underboost code. You could remove the 4 bolt inlet pipe form the combustion chamber and drive it to see it it makes any difference. If you do make sure to remove both BCU fuses. If you have DX2 this would be much easier. Good luck keep us posted.
 
  • Like
Reactions: roderex

Hino123

Expert Expediter
Researching
Offline
Just re-read your post. Do you have any soot or exhaust leaks. Where is the hissing sound coming from. Is it more notable with the exhaust brake on?
 

roderex

New Recruit
Owner/Operator
Offline
The hissing sound is coming from the exhaust, only happens when the engine is on low power mode. I can hear air puffing out from the air filter also when the engine is on low power. The rpm only goes to 2k max when its low power. Am i on limp mode/derate during this times?

In that one hour that i let my engine cool down. All of the sudden when i start the engine it sounds normal again and have boost again until i go to the highway on a warm day and it will lose power again. Unfortunately i do not have a sister truck to swap sensors with. I might try changing those sensors first by tomorrow and i will inspect the egr valve and cooler for carbon build up.
 
Last edited:

greasytshirt

Moderator
Staff member
Mechanic
Offline
I haven't encountered this before. The exhaust hissing is curious. I'd be tempted to separate the exhaust pipe BEFORE the exhaust brake to rule it out definitively. I have seen them rust and get jammed up on rare occasions.
 

roderex

New Recruit
Owner/Operator
Offline
Thank you guys for your replies. as of now the truck has totally lost power. I might just change the engine. I have found an engine its from a later model 2015 j08e-VC. it has the same engine code as my 2011 hino. it looks the same also. can you guys confirm if this will fit/work with my 2011 hino without issues? thanks
 

roderex

New Recruit
Owner/Operator
Offline
right now it has totally no power..will the 2015 j08e vc engine fit on my truck without no issue?.. mines 2011 but has the same engine code j08e vc..
 

greasytshirt

Moderator
Staff member
Mechanic
Offline
The block, head, and rods are the same, but there may be some internal differences. The ECU programming is different. There's a completely different method of DPF heating between 2011 and 2015. Many external parts are different.

I know you're very frustrated but this is one heck of a parts cannon move.

It would be a nightmare to swap the engine only to find that the condition still exists.
 

roderex

New Recruit
Owner/Operator
Offline
it starts but when i rev it it won't get past 1500 rpm. before it always has power at first before losing power.now totally no power. it has been a total nightmare. it has no engine fault code and it totally lost power. it has been at the dealership twice and some other indie shop no one solved the problem.
 

greasytshirt

Moderator
Staff member
Mechanic
Offline
When troubleshooting problems like this, we gotta go back to the basics, check all the easy stuff, and rule out as many things as possible without spending any money.

When you turn on the ignition, the VNT controller should cycle. Does that happen?

Put your hand on the compressor wheel of the turbo. Does it spin freely?

Rule out the entire exhaust system. Unbolt the exhaust pipe and whatever brackets stabilize it and disconnect it from the turbo entirely. Will this allow it to rev freely?
 

Hino123

Expert Expediter
Researching
Offline
This guy has posts all over the internet on this truck. Seems like he just wants you to use your crystal ball to fix it for him. If he would answer the questions and do some of the visual inspections we could probably come up with a solid solution IMHO. I have seen this issue before on a truck. It would not rev up over 1500 and there was no check engine light. ✌
 
  • Like
Reactions: roderex

roderex

New Recruit
Owner/Operator
Offline
hey hino123 im just like all other people that want their work truck back on the road. what do you feel every single shop and even the dealership can't fix your work truck? would you jump for joy
 

roderex

New Recruit
Owner/Operator
Offline
the turbo has been inspected and replaced with oem brand new. the charge hose changed, egr valve replaced with oem brand new, egr cooler cleaned inspected, the exhaust inspected and baked/cleaned, fuel filters replaced twice! maf sensor changed with new oem.tranny fluid changed,oil changed. with all that i spent trouble shooting my truck i could have bought another engine with the money. that is why not just to get this over with. plus i will have a spare engine for parts. do you think were not doing something here mr hino123?
 
Last edited:

greasytshirt

Moderator
Staff member
Mechanic
Offline
I am approaching this problem like it's in front of me in person, for the first time.
I don't care about all those parts you've thrown at it. I'm going to start from the beginning with the basics.

Can air physically get into and out of the engine? I asked you about the exhaust brake, got no answer. Take the downpipe off the turbo and you'll eliminate everything downstream.
 
Top