Cp4 GMC Duramax conversion to cp3 common rail high pressure fuel pumps or similar.

[jjeff]

Anyone have experience with this seeing as I made the decision to keep my Sierra and outfit it with more useful options as miles add on I want to take care ahead of time what some call that generations Duramax lml I believe "Achilles heal" cp4 pump is known to self destruct taking out fuel rails injectors etc. I've seen complete cp3 complete bolt in kits out there that reportedly don't mess with emissions or anything else electronically on truck systems and no retune needed. Seen the complete kits practically bolt in for less than a grand. Whereas a cp4 pump self destructs it will cost 10k plus to repair at a garage . I've seen upgraded cp4 x bolt in pumps but not for a Duramax in my lackluster internet searches. I don't want a tuner or even emissions delete. I have noticed a slight drop in fuel mileage by about 1/2 up to two gallons depending what Im Hauling and what speed im going at. Truck only has a little over 125k and is a 2016. Insight,suggestions, and experiences are appreciated. I believe some generations of ram cummins and Ford power strokes also use the cp4 pump and there was a class action lawsuit in the works.

 

[Topzide]

The CP4 "glitter bomb", is a ticking time bomb! No experience with doing this but know of 2 with Rams that had theirs replaced under warranty. One before and one after the explosion! On a quick search, seeing several kits that don't require tuning and have 50 state EO#'s. Is this something that you were going to tackle or farm work out? Some of the sites recommend a shop do the install as they don't support diy installs. Pricing is $1800 and tops out around $2500. Good luck.

 

[jjeff]

Yes find a shop fingers crossed it's a good competent one. my skill set on modern high pressure common rails are lack luster besides being able to change the fuel filter frequently. A couple thousand before a destroyed cp4 makes more sense to me anyway especially if I'm keeping the truck for the foreseeable long term future.

 

[Snobdds]

I don't know much about duramax's, but I do know there are CP4 replacements for a powerstroke. Maybe it could work for a cheby too...

DCR pump conversion. Eliminates the issues with the CP4

Ford 6.7L DCR Pump Conversion | Flying Wrenches

More durable plug-and-play replacement for the CP4 Does not require any ECU calibration OE fit and function Two-piston DCR pump co-developed by S&S/PurePower Biofuel and low-lubricity fuel compatible Patented Eccentric Drive pumping technology Pressure-lubricated cam and bushings...

www.flyingwrenches.com

 

[jjeff]

So Initial estimate for a cp3 conversion done by what seems like a competent knowledgeable shop Specializing in Duramax engines iand Allison transmissions is 6k includes a 4 yr unlimited mileage warranty. On new cp3 pump and all related components so I guess I'll put my dumper dog box on Temporary hold . Before I spend a fortune to me on this anyone go thru with this conversion what were the results? Power, fuel mileage etc.more important reliability. I definitely don't have a big a problem spending cash hiring others to do things for me I have limited or no knowledge of as long as it's done right and how id attempt to do it correctly. Could buy quite a few winter beaters that I'm comfortable working on for this upgrade. In retrospect even a new 1 ton Duramax with limited functional options retails without incentives for close to 70k. Plus I'd be very leary and not enjoy using it like a pickup truck at that price.

 

[jjeff]

According to who I'm buying my new boss v plow from it was one of there top of the line plows, only several yrs old , its never even plowed snow, always stored inside, pictures and Initial inspection by me due in the coming weeks. Figure even if I don't want to drive 500 miles with it on my truck up north I still have my subcompact with manual angle plow I hacked together to work on my tractors loader arms qa up there.

 

[Snobdds]

What?

 

[jjeff]

What?

Pretty much getting a top of the line several yr old brand new boss v plow for pennies on the dollar minus buying a new frame mounted attachment plate for my 3/4 ton truck. Is what I boastfully tried to convey. Meanwhile looking at 1/2 ton crewcab trucks with the 3.0 Duramax. Thoughts or opinions on the 3.0 Duramax for a daily driver and grocery getting light single axle trailer tow vehicle? Things are happening pretty quick.

 

[jjeff]

Posted plow in in wrong thread. Maybe I should get a white 1/2 ton It definitely fits my tech skill age.

 

[Topzide]

Isn't the 3.0 Duramax the one with timing belt that requires the engine to be pulled?

 

[jjeff]

Yes gm upped that service to 150k miles I think. There's is something to it involving the oil pump I believe also buddy who owns the 3.0 says they can change it by pulling the transmission instead, even so if I own something for150k miles since new I don't mind doing or hiring someone to do pretty extensive maintenance to it if it's not what I consider a problem riddled lemon.

 

[Hay Dude]

So Initial estimate for a cp3 conversion done by what seems like a competent knowledgeable shop Specializing in Duramax engines iand Allison transmissions is 6k includes a 4 yr unlimited mileage warranty. On new cp3 pump and all related components so I guess I'll put my dumper dog box on Temporary hold . Before I spend a fortune to me on this anyone go thru with this conversion what were the results? Power, fuel mileage etc.more important reliability. I definitely don't have a big a problem spending cash hiring others to do things for me I have limited or no knowledge of as long as it's done right and how id attempt to do it correctly. Could buy quite a few winter beaters that I'm comfortable working on for this upgrade. In retrospect even a new 1 ton Duramax with limited functional options retails without incentives for close to 70k. Plus I'd be very leary and not enjoy using it like a pickup truck at that price.

Mine was done under a Ram national campaign. Final cost was like 8k, but $0 for me.
I think the truck might have lost just a tiny bit of power. The CP-4 is a higher performance pump than a CP-3, but it’s not reliable, maybe that’s why.


I’m assuming you are stuck with a CP-4 out of warranty?

 

[jjeff]

Mine was done under a Ram national campaign. Final cost was like 8k, but $0 for me.
I think the truck might have lost just a tiny bit of power. The CP-4 is a higher performance pump than a CP-3, but it’s not reliable, maybe that’s why.


I’m assuming you are stuck with a CP-4 out of warranty?

Correct it's a 2016:with about 125k on it I'm keeping that truck might as well have it done now or pay 2x more later. The cp3 conversion is definitely expensive. However it sure seems like this shop that only specializes in Duramax engines and allison transmissions know what there doing and have been in business since the lb7 generation. So 20+ yrs. They also took the time to give me a pretty thorough overview of what they'd be doing and what may be found including possible further procedures to mitigate any issues found.

 

[Racer4]

Our 2010 VW Touareg has a cp4 pump. 237,000 mi so far. I do give it a shot of power service every couple tanks. Fingers crossed.

 

[jjeff]

Isn't the 3.0 Duramax the one with timing belt that requires the engine to be pulled?

It's actually the oil pump belt that should be replaced at 150-200k miles why they use a internal belt to run the oil pump is beyond me. I think it uses a timing chain also. And early versions had timing chain not belt problems from what I heard from my friend who owned one.

 

[jjeff]

Our 2010 VW Touareg has a cp4 pump. 237,000 mi so far. I do give it a shot of power service every couple tanks. Fingers crossed.

Ive used a fuel lubricity additives fairly often changed fuel filters pretty frequently and rarely ran the ,fuel tank below a 1/4 needless to say im pretty confident it's not going destroy itself for awhile I hope. However it will probably be a $12k job if it does.

 

[ruffdog]

 

[jjeff]

Definitely not a shady tree weekend project for me anyway.

 

[Hay Dude]

Definitely not a shady tree weekend project for me anyway.

I’d skip that video just based on the looks of that guy. lol

 

[Hay Dude]

Correct it's a 2016:with about 125k on it I'm keeping that truck might as well have it done now or pay 2x more later. The cp3 conversion is definitely expensive. However it sure seems like this shop that only specializes in Duramax engines and allison transmissions know what there doing and have been in business since the lb7 generation. So 20+ yrs. They also took the time to give me a pretty thorough overview of what they'd be doing and what may be found including possible further procedures to mitigate any issues found.

I guess if the juice is worth the squeeze.
6K into a truck worth??? What were you asking?

And you were going to sell it to me with a CP-4????
Shame on you.
We’re not buddies anymore.