LML CP4 Problems

stroke250

I May Be Lost...
Jul 1, 2008
490
18
18
Idaho
If anyone wants to donate some of those new CP4's in the pump kits, I am always available. :hug:

We are currently working on a kit that will prevent the contaminants from entering the high pressure side. The first prototype worked flawlessly, however, we are trying a new design now that will cut costs drastically for the end user if successful. :thumb:

Anxious to see the results and end product.
 

LBZ

Super Moderator
Staff member
Jul 2, 2007
9,905
151
63
46
B.C.
So did I dream this or did I hear talk of one of the drawbacks to the cp3 conversion was it created a lope or something odd like that?
 

LBZ

Super Moderator
Staff member
Jul 2, 2007
9,905
151
63
46
B.C.
I would think that would be a tuning issue. Not strictly due to the CP3
I believe you would be right, but I think that was part of the problem. On some trucks the problem couldn't be tuned out.

Would need to hear from someone who encountered it directly I guess.

My thoughts on the best route would be to throw on a lift pump and the new fangled bypass when it comes available and try to make it live off warranty this way.
 

stroke250

I May Be Lost...
Jul 1, 2008
490
18
18
Idaho
So did I dream this or did I hear talk of one of the drawbacks to the cp3 conversion was it created a lope or something odd like that?

I never had any loping issues with my CP3 conversion(Exergy Sportsman) on my 2011. I would venture to say to any related issue like it would be tuning or part(bad) related.
 

LBZ

Super Moderator
Staff member
Jul 2, 2007
9,905
151
63
46
B.C.
the rail surge is what is the draw back to a cp3 swap it can be tuned out but some trucks take a looootttt of tweaks.

With the strides exergy has made on cp4s I would just do a stroker cp4 and call it a day.
There's nothing on their site for info.
I wonder what sort of improvements they are making to help these things last?
 

Steveoduramax

New member
Feb 1, 2019
3
0
0
socal
hi new member . i have a 2016 duramax 74k miles 2nd owner. i bought from dealership at 19k miles. my cp4 just went out ruined the whole fuel system. chevy is saying warranty doesnt cover it. my warranty book says truck has 5yr/100000 powertrain. one dealership says its 5yr/50000.any help would be thankful. i cant afford 10k for this repair..
 

2004LB7

Super Moderator
Staff member
Dec 15, 2010
7,132
2,226
113
Norcal
From here: https://www.chevrolet.com/important-information

"Every 2016/2017 2500/3500 series Heavy Duty (HD) Silverado Pickup equipped with a 6.6L Duramax Turbo-Diesel Engine comes with a 5-year/100,000-mile Limited Powertrain Warranty and 5-year/100,000-mile 24/7 Roadside Assistance Program and Courtesy Transportation Programs."
 

06gmc

Loud and Heavy
Jun 24, 2017
97
0
6
SWMO
unless you have done something to the truck to void then warranty it should definitely be covered. Is the truck completely stock?
 

Steveoduramax

New member
Feb 1, 2019
3
0
0
socal
after talking to chevrolet directly multiple times they some what agreed the cp4 is covered.Then talking to my nearest dealership back in fourth for hours. They kept saying just bring it in and let us look at it. My response was its a simplke question is the cp4 covered. After debating forever i was finally told its covered and to tow it in.ill keep yall posted on what happens.My next question for you folks what should i do to prevent this again. cp3 swap is not a option for about a year.
 

clrussell

pro-procrastinator
Sep 23, 2013
5,928
399
83
Dealer just covered one of my customers 15 cp4 failure. Truck had 98k on it. Gave him a two year unlimited mileage warranty with the repair.
 

clrussell

pro-procrastinator
Sep 23, 2013
5,928
399
83
Beings he was a customer Corbin was the truck tuned at all? Lift pump?

100% stock. He purchased used and the pump went a week later. He’s been a long time customer, we just hadn’t got to the goods on this truck yet.