Brain Trust Input Please ---- Isuzu Box Truck DEF issues

[J DUNN]

I have a 2016 Isuzu NQR we use for hauling cabinets that has 181,000 miles. It won't go above 45mph and our regular shop for oil changes and minor maintenance says it's a DEF issue that you need to take to a dealer.

Dealer quote is below, roughly $12k repair. I bought the truck brand new for $45k-ish and have gotten some good life out of it. Here are the options I see, listed in the order I'd most likely do them.

1. Sell or trade in truck for a new cab and chassis, go to box company and have them swap the box and lift-gate to the new chassis.

2. Fix it at current dealer and bite the bullet.

3. Take it to another dealer for another quote?

4. Get some illegal/janky advice from RDP and take it to some illegal shop that will bypass and cut all the DEF out which will only lead to smog cert issues down the road.

5. RDSUX, try a new forum



Dealer Quote

Replace DEF Injector
Labor: $210.00
Parts: $489.22
-(1.0) INJECTOR ASM; D


Replace DPF and SCR asms
Labor: $1,260.00
Parts: $7,006.72
-(1.0) DPF FI W/O CORE $2,301.39
-(1.0) CATALYST ASM; D $4,436.69
-(1.0) GASKET; DPD $47.72
-(1.0) GASKET; DPD $39.39
-(3.0) GASKET; FILTER, $60.51


Replace Contaminated NOx sensors
Labor: $420.00
Parts: $1,778.72
-(2.0) SENSOR;DEF DCM $889.36

 

[ChumpChange]

Where are you located? What dealer? PM if you’d like as I have a couple Isuzu dealers as customers.

 

[QC22]

Something is not right. Why replace the DEF injector? If that’s the only problem, then why replace the DPF AND SCR? Both can be cleaned. What’s the fault? This quote looks like 100% of the after treatment replacement. Super overkill unless there is missing info.

 

[evantwheeler]

4.

 

[Justsomeguy]

Something is not right. Why replace the DEF injector? If that’s the only problem, then why replace the DPF AND SCR? Both can be cleaned. What’s the fault? This quote looks like 100% of the after treatment replacement. Super overkill unless there is missing info.

I agree.

4.

I will never promote breaking the law. I will also not disagree, it's a solution that has many benefits. Also downsides.

 

[Bigbore500r]

I have a 2016 Isuzu NQR we use for hauling cabinets that has 181,000 miles. It won't go above 45mph and our regular shop for oil changes and minor maintenance says it's a DEF issue that you need to take to a dealer.

Dealer quote is below, roughly $12k repair. I bought the truck brand new for $45k-ish and have gotten some good life out of it. Here are the options I see, listed in the order I'd most likely do them.

1. Sell or trade in truck for a new cab and chassis, go to box company and have them swap the box and lift-gate to the new chassis.

2. Fix it at current dealer and bite the bullet.

3. Take it to another dealer for another quote?

4. Get some illegal/janky advice from RDP and take it to some illegal shop that will bypass and cut all the DEF out which will only lead to smog cert issues down the road.

5. RDSUX, try a new forum



Dealer Quote

Replace DEF Injector
Labor: $210.00
Parts: $489.22
-(1.0) INJECTOR ASM; D


Replace DPF and SCR asms
Labor: $1,260.00
Parts: $7,006.72
-(1.0) DPF FI W/O CORE $2,301.39
-(1.0) CATALYST ASM; D $4,436.69
-(1.0) GASKET; DPD $47.72
-(1.0) GASKET; DPD $39.39
-(3.0) GASKET; FILTER, $60.51


Replace Contaminated NOx sensors
Labor: $420.00
Parts: $1,778.72
-(2.0) SENSOR;DEF DCM $889.36

Looks like a "parts swapper" wrote up the quote.....i.e, they don't know how to troubleshoot, so they just throw the kitchen sink at it with parts and hope replacing anything and everything related to the exhaust emissions system fixes it.

I'd start by getting a second opinion - see if there is a good independant diesel mechanic who does Isuzus, let him take a look.

 

[monkeyswrench]

If you can, find out what codes it's throwing. Injector going bad is pretty rare on NPR's. More often than not, injector performance is bad due to the DEF filter in the tank being clogged or contaminated. Occasionally the injector tip may get clogged up...if someone has the IDSS software, they can crank up the def pump pressure and clear it out.

If it's a DPF of "SCR catalyst performance" code, there are some cleaners you can run in the fuel, and do a couple forced regens. Had a customer that didn't want to bite the bullet yet...a treatment every month and a half or so limped it along for another year.

 

[BUDMAN]

Where are you located?

 

[J DUNN]

Where are you located?

Orange County, CA

Fullerton

 

[mattyc]

I have a 2016 Isuzu NQR we use for hauling cabinets that has 181,000 miles. It won't go above 45mph and our regular shop for oil changes and minor maintenance says it's a DEF issue that you need to take to a dealer.

Dealer quote is below, roughly $12k repair. I bought the truck brand new for $45k-ish and have gotten some good life out of it. Here are the options I see, listed in the order I'd most likely do them.

1. Sell or trade in truck for a new cab and chassis, go to box company and have them swap the box and lift-gate to the new chassis.

2. Fix it at current dealer and bite the bullet.

3. Take it to another dealer for another quote?

4. Get some illegal/janky advice from RDP and take it to some illegal shop that will bypass and cut all the DEF out which will only lead to smog cert issues down the road.

5. RDSUX, try a new forum



Dealer Quote

Replace DEF Injector
Labor: $210.00
Parts: $489.22
-(1.0) INJECTOR ASM; D


Replace DPF and SCR asms
Labor: $1,260.00
Parts: $7,006.72
-(1.0) DPF FI W/O CORE $2,301.39
-(1.0) CATALYST ASM; D $4,436.69
-(1.0) GASKET; DPD $47.72
-(1.0) GASKET; DPD $39.39
-(3.0) GASKET; FILTER, $60.51


Replace Contaminated NOx sensors
Labor: $420.00
Parts: $1,778.72
-(2.0) SENSOR;DEF DCM $889.36

I would recommend you get a second opinion. There are three components there that all play a role in the same system. Did they provide test results or a reason for condemning each component? Sounds like a shotgun repair to me. You cant condemn an SCR with faulty nox sensors. Did they provide you with any codes that were set?

 

[J DUNN]

This is dealers input:

Scanned truck and found code P20C9 (DEF control module requested MIL illumination) P208E (DEF injector stuck)
downloaded health report and also found code P2000 (DEF System NOx Trap Low Efficiency) oil level ok, Fuel API
rating of 48 (High), low side fuel pressure at 84psi and 185psi at WOT (Normal), there is soot in tailpipe , removed
NOX sensor #2 and found contaminated with soot, more than likely both the DPF and SCR have been breached, went
through diag flow chart for P208E code, tested resistance of injector and found at 2.9 ohms (Needs to be between 11
and 14 ohms, DEF Injector will need to be replaced, recommending replacement of DPF Injector, replacement of both
SCR and DPF Assemblies along with replacing both NOx Sensors then performing manual regeneration to make sure
temperatures get up to specs

 

[rivermobster]

@OCMerrill is an expert on these.

 

[J DUNN]

I really appreciate your guys help and input. Thank you for taking time out of your day to help me even though there is no boating content in this thread.

 

[monkeyswrench]

I really appreciate your guys help and input. Thank you for taking time out of your day to help me even though there is no boating content in this thread.

It's related to boating. Income to boating coefficient...hell of a lot more important than light beer or rainbow flags

 

[DaveH]

the really janky thing to do would for the DPF to be stolen (unheard of in these days) and insurance repairs the truck.

 

[hman442]

Sounds like that dealer wants to change every possible item, to ensure that it is fixed. Is there a good independent shop in your area that would diagnose the actual issue/code? All of those components didn't fail at the same time! However, be prepared for one component failed, the Cat & screens are 95% clogged, etc. Hopefully you can get into a shop that'll give you options, and help you make a good decision, instead of just replacing all of it.

 

[OCMerrill]

@OCMerrill is an expert on these.

Unfortunately not so much a DEF Isuzu.

I agree with @hman442 though. Dealers of heavy equipment heavily watched over. Need an independent guy that can actually clean the DPF.
Perhaps running a additive to light off the catalyst in the DPF filter so the SCR can do its job.

All my Isuzu's were NPR's of the early 2000 vintage and shit they rarely broke down for anything. Best business truck ever and they are missed often. Fuck you CARB.
I have since decided to give allowances so employees use their own trucks.

 

[RVR SWPR]

I really appreciate your guys help and input. Thank you for taking time out of your day to help me even though there is no boating content in this thread.

Ask Kevin (Monkeywrench) talk you on phone for few minutes. We had same regen issues. Kevin has correct info. Thanks again MW.

 

[24 Sleekenforcer]

Sure sounds like you need to start with a DEF injector, most likely not enough def fluid in the system to generate enough heat to burn the soot from the DPF . Then run a regeneration several times to clean it up. I have a d-max ounce the took 19 regs to get it clean.

 

[24 Sleekenforcer]

Also make sure your air filter is clean and clean the MAF sensor. This is a overlooked on diesel’s. If the engine can’t breathe it plugs the DPF .

 

[BAS]

These are wear items. They all go in line with each and get repaired and cleaned at the same time. You can clean them, call DPF Alternatives on LA. I’ve never serviced a DPF and not an SCR at the same time nor do knock sensors and not done the inlet and outlet at the same time. I ran all my trucks that broke down in California through Chris Romash at Sierra Truck Repair, Fontana. He’d fix them or tell me where to go. Pm me I price maybe I’ll be it as is

 

[colenighthawk]

Orange County, CA

Fullerton

Is your shop on Fender Ave by Sam's club and Homedepot?

 

[J DUNN]

Is your shop on Fender Ave by Sam's club and Homedepot?

No, close though. Down Acacia between 91 and Orangethorpe.