CP4 Scare - Fuel filter 2013 Checy 3500 Duramax

matt86m

matt86m

Well-known member
Joined
May 6, 2021
Messages
1,028
Reaction score
1,216
Had a bit of a 'scare' with my truck last week.

Driving to Mesa, AZ, Im 35 miles from a buddy's house when the motor died on me in heavy traffic and wouldn't start. AAA to the rescue.

History: 2013 Chevy Duramax, 57,000 miles, VERY well taken care of (except by me as you will see :lol:  ) Had a slight 'hard' start after it sat for a couple weeks, didn't think anything of it. Started fine after that. Loaded it up and got to Tom Wells Rd in AZ and had to crank it for 30 seconds or more before it started. While driving 70-75 had a couple slight hesitations in the throttle, got into stop n go traffic and it died. Right before it died I did get a "change fuel filter" warning on the dash then it disappeared. 

Mistakes: I didn't check the dash info to see how much fuel filter life was left before leaving! Had 7000 miles on it since the last change. I owned an '07 Dually/Duramax for 9 years and always changed the fuel filter every other oil change (5000 mile intervals)

While we were in Texas hunting, one of Joe's guys changed the fuel filter but couldn't get it to stay primed. He just went thru the dreaded CP3/CP4 destruction and it cost him over $10,000 to fix the fuel system.

Turns out he didn't get ALL the air out of the filter - didn't prime it enough. When we got home another guy came over with a scanner, NO codes and he primed the filter as I turned the key. It took A LONG time and 4-5 times before it stayed running. Let the truck idle for over an hour, started it several times and all was good. Was able to drive home with no problems.

Are you still reading?! :lol:  

As I was passenger for an 11 hour ride I was able to read nightmare story after story of CP4 (that's what I have) failures.

SO,,,,my question, what have you done to 'prevent' this from happening?

I have read about lift pumps - not cheap but a HELL of a lot cheaper than the thing scattering metal thru the fuel system.

What else is there to help prevent it from happening?

:cheers:

 
Last edited by a moderator:
I have a 2016 duramax and have the same CP4 fears. From what i've read and been told the best option is to run a lift pump and add a diesel additive to the fuel every time you fill up or you can do a CP3 conversion. I got quotes for both and doing the lift pump is the cheaper option but not by much. I guess the reason for the CP4 failures is because U.S. diesel is too clean for it and does not lubricate the pump properly. The station that I fill up at only sells the renewable diesel fuel and from everything I've read its actually a much dirtier (more oils) fuel than regular diesel which is actually a good thing for the CP4 because it helps keep it lubricated better. I don't have a lift pump either, I just throw some additive in the fuel every time I fill up and so far I haven't had an issue. I bought my truck with 60k miles and currently have 85k on it. Fingers crossed everything stays good lol I'm probably selling the truck next year and buying a 2021 or newer so I don't really feel like putting the money into this one. 

Also, I could be completely wrong with everything I just posted but that is the information I was able to find on all the forums and research I have done

 
I have a 2011 LML. I added a lift pump and the install was not terribly hard. Worst part was draining the tank to add the sump pump. I could help you do it if needed.

I also run an additive as well. Lubrication additive from https://www.hotshotsecret.com/lx4-lubricity-extreme/

Also added the fuel system saver from https://www.wcfab.com/i-31420523-exergy-performance-system-saver-improved-stock-inlet-metering-valve-fca-mprop.html

There is alot of talk on the internet of failures but if you look at the true data, its really a small amount.

 
Carwashguru said:
I have a 2011 LML. I added a lift pump and the install was not terribly hard. Worst part was draining the tank to add the sump pump. I could help you do it if needed.

I also run an additive as well. Lubrication additive from https://www.hotshotsecret.com/lx4-lubricity-extreme/

Also added the fuel system saver from https://www.wcfab.com/i-31420523-exergy-performance-system-saver-improved-stock-inlet-metering-valve-fca-mprop.html

There is alot of talk on the internet of failures but if you look at the true data, its really a small amount.
Click to expand...
I may say a little differently about the percentage, my son works @ Ford in Irvine, they have over a dozen SuperDuty's in their service department right now that have failed CP4 pumps. The worst parts is Ford is blaming the owners of these trucks and trying to deny the claims. @ $80-100k for a truck, they should be kissing the customers asses with those expedited repairs.

 
Last edited by a moderator:
I got tired of sleepless nights and just did the S&S Cp3 conversion 4 years ago along with a fass lift pump. Anxiety is way down now. Now I Just worry a little about the emissions crap is all. 🥴

 
my buddies early 2015 LML failed at like 55k and the repair was $11k but the guy who did it filed an insurance claim for bad fuel causing the issue and he got the whole thing covered through his car insurance.  (shop is aGD member).  my truck is a 2013 LML and i went 250k miles with a stock setup, no lift pump, no additives. at 250 i did everything. i replaced the radiator, water pump, every water hose on the engine, radiator lines, and the fuel pump.  i decided to go with a new GM fuel pump, the same C4.   i looked at the conversion but i believe it had risks of smog issues, like there is an extra hose on the cp4 that cant get hooked upif using a CP3, etc.  I felt with all the bad press on the current pump and possible class action, that the newest GM  pump would be even better than its CP4 predecessor.  that was a lot of work, i dont wish that on any buddy and i did it myself.

just so you know how it works (at least on my truck) there is no lift pump so the CP4 does all the work of sucking the fuel from the tank, through the filter and up to the top front of the motor!  so the slightest plugged filter causes a big issue in that the pump can now cavitate.  by installing a lift pump it now supplies the filter and CP4 inlet with pressurized fuel and its easier to push through a plugged filter then to suck through one. thats why its important to replace filters early.

the lift pump is a great idea.  i think what's on the market is way overkill so i opted not to.  it hink Ford later has started to put electric lift pumps in their trucks with the CP4 and has a lot better luck then chevys without it

 
the issue is contamination of the fuel... Def, water... then the pump goes bye bye....even with a lift pump

 
Your only options besides a CP3 conversion are installing a lift pump, religiously utilizing fuel additive, regular filter replacements and driving the truck regularly. Most of the people I know that have had this issue usually do not have lift pumps or are not participating in the items i mentioned. I know several 200k plus mile LML owners that maintain their rigs properly under daily use without injector pump failure. 

CP3 conversions can be risky business regarding emission regulations. However, there are 50 state legal conversions that do have a CARB  EO#. S&S has one for example: https://dmaxstore.com/products/?route=product/product&path=2290_1065_2030_2036_2148&product_id=2213

 
i had a cp4 fail on my 11 lml   cause i just have to know why it failed i took it apart.  So there is a small gear pump on the back that draws fuel from the tank that was the actual failure. my assumption is that the gear pump struggles to draw the fuel from the tank at the rear of the truck possibly cavitates and starts to disintegrate the small metal particles then go into the high pressure section of the pump which are ceramic pistons with very tight tolerances the smallest bit of junk will stick the piston and destroy the pump and contaminate the rest of the system. so by adding a lift pump. The lift pump built in has very little load on it. now if you actually get contaminated fuel with water in it the water will destroy the pump in minutes when you heat and pressurize the water to 25k psi it will gaul the metal and the pistons in the pump will seize.      A new pump is about 1000.00 dollars for the pump and not too bad to change but if you have to do the rails injectors cooler lines your in for a big bill. i got away with only changing the pump but there is still bad injector or something because when it is hot it is hard to start it has been that way for the last 100k miles the truck has 200k on it and a ton of idle hours it runs 10 hours a day 5 days a week so the hours are thru the roof

 
Last edited by a moderator:
I agree with @Carwashguru about the internet hype and actual low numbers.  There are millions of CP4 pumps out there and the failure rate is small in comparison.  That being said I have 3 friends that have had CP4 failures in their LML Duramax's.  I bought a used 2014 LML in July 2021 with 207k miles.  The previous owner had always used Diesel Kleen fuel additive and had a Fleece in tank lift pump installed.  I switched to a Caterpillar fuel filter and oil filter.  I recently added a deep sump oil pan but not for the added capacity.  I did it because the stock GM pans hold about a quart of engine oil in them that cannot be drained.  The AFE deep sump pan doesn't have this issue.

I'm at 270k miles.

20220604_175934.jpg

20220604_175938.jpg

This is how much oil cannot be drained from a stock GM pan.

 
Realbadlarry said:
the issue is contamination of the fuel... Def, water... then the pump goes bye bye....even with a lift pump
Click to expand...
DEF is only injected in the cat/particulate filter downstream of the fuel pump and motor,  correct?

the the pump spends its lift in suction without a lift pump, so its harder on it and with the lift pump it has pressurized fuel constantly on the inlet side

(again i dont have a lift pump) but service my filter understanding the system
 

RE:  thats another good reason to change the filter as it is a water separator and the GM has a water sensor, i have never seen it show water ever

 
Last edited by a moderator:
nzulmer said:
Your only options besides a CP3 conversion are installing a lift pump, religiously utilizing fuel additive, regular filter replacements and driving the truck regularly. Most of the people I know that have had this issue usually do not have lift pumps or are not participating in the items i mentioned. I know several 200k plus mile LML owners that maintain their rigs properly under daily use without injector pump failure. 

CP3 conversions can be risky business regarding emission regulations. However, there are 50 state legal conversions that do have a CARB  EO#. S&S has one for example: https://dmaxstore.com/products/?route=product/product&path=2290_1065_2030_2036_2148&product_id=2213
Click to expand...
that kit is $2600 bucks  yikes.  my new updated CP4 was like $500 and when i pulled out the old one at 250,000 miles it was beautiful too literally thought why am i replacing it!

i would rather save the $2100 and replace the pump every 100k

 
You must log in or register to reply here.
Back
Top