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CP4 to CP-ISB21S3 (revised CP3) change for 2021 6.7L Diesel Trucks -- Merged Threads

Epsilon Plus said:
Are you hard up for a truck? 12% off MSRP is the Net accepted norm pretty much all year long. Difference being now that since RAM is promoting it the dealer just gives it to you without the annoying haggle.

I love my RAM and am not here to tarnish the brand but I wouldn't be caught dead buying a 2020 without further developments in whether there will be a TSB/Recall for them.

If you just can't wait, build dates July and after should have the the revised symmetrical cam CP4. Otherwise see here for the "dimple":

hdrams.com

How to tell if you have the Asymmetrical CP4 or new Symmetrical CP4 -- MOD[DO NOT DISCUSS THE CP3 CHANGE IN THIS THREAD]

[MOD: HPFP Recall issued 11-11-2021] Compliments of @Jimmy07 : Here’s two advanced communications for it: https://drive.google.com/file/d/17Iw3kDj_LagGfe0yds7PCPcb0UGyeJkd/view?usp=drivesdk https://drive.google.com/file/d/1lZTH2UY2mvIR2bSBgyxg5lBzBBq2XbAA/view?usp=drivesdk
hdrams.com hdrams.com
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I should add, I'm currently at 16% discount to MSRP without trying for more due to CP4. That may change calculus?
 
Last edited by a moderator:
16% off
Call industrial injection and get their drop in CP3
Save some money and be done with it

Also how many of you guys trust your local dealer to successfully convert the pumps? Hearing about the service centers horror stories is trust it coming from the factory over anyone else except maybe myself or a trusted diesel shop.


Sent from my iPhone using Tapatalk
 
Admin said:
Just heard back from my PR rep at RAM. Confirmed directly from them that they did change the pump for 2021 and he's just checking for me now to see if the change applies to the HO as well since we have only seen the standard output so far.

Looks like I really did buy my truck a few months too early, the funny thing is I factory-ordered one when it looked like I wasn't getting this one and that factory order got switched to a 21 and is just about to be built lol.
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Did rep have any thoughts on a possible TSB or recall?
 
4,000 thread views in 3 days. If you haven't guessed, this is pretty big news to the RAM HD enthusiast world.

As for trusting the techs to do the work, I'll take my chances. Its either them swapping it to a 3 or changing the entire fuel system when my asym punches the clock. Tearing my dash out for a 7 hour A/C improvement? No thanks. OEM CP3 swap? I'd be first in line if possible.
 
So they obviously didn't have ANY faith in the CP4.2 pumps if they only used them for what, 4 months?
 
For them to make the change for production trucks this fast they have had to have it planned for several months. They did wait for in-field results from the new version pump.
 
TXramHD said:
So they obviously didn't have ANY faith in the CP4.2 pumps if they only used them for what, 4 months?
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2019-2020 so more than 4 months. Two full production year models.

CP4.2 is a 2 piston CP4

The original asymmetrical cam lobe pump and the new single dimple symmetrical pump are both CP4.2 pumps.
 
Brutal_HO said:
2019-2020 so more than 4 months. Two full production year models.

CP4.2 is a 2 piston CP4

The original asymmetrical cam lobe pump and the new single dimple symmetrical pump are both CP4.2 pumps.
Click to expand...
Ah ok. I wasn't aware they put the cp4.2 into trucks before September. Thanks for clarification.
 
There still have been no Internet reported failures of the dimple. July to now is enough out there and enough miles to have heard of something by now I figure.

Id still rather have a CP3, but hell I've got the hair trigger pump, Id take the dimple at this point!
 
Epsilon Plus said:
There still have been no Internet reported failures of the dimple. July to now is enough out there and enough miles to have heard of something by now I figure.

Id still rather have a CP3, but hell I've got the hair trigger pump, Id take the dimple at this point!
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Me too, my truck is a July build if I recall correctly and it's the original CP4.2 lol, probably one of the last ones built before the change over.

To be perfectly honest though I'm not super concerned about it, I'll just make sure the truck is gone before the warranty is up. Hell I haven't even taken photos and written an article on it yet introducing it as our new long term test truck.
 
Does the guy at FCA who in 2017ish said "yeah let's go with that one," spend a lot of time hiding in the crapper these days?? I can't help but wonder..
 
Admin said:
Me too, my truck is a July build if I recall correctly and it's the original CP4.2 lol, probably one of the last ones built before the change over.

To be perfectly honest though I'm not super concerned about it, I'll just make sure the truck is gone before the warranty is up. Hell I haven't even taken photos and written an article on it yet introducing it as our new long term test truck.
Click to expand...

After reading about how the front cover and maybe timing gear and some other stuff is different I could see them just TSBing the asym pumps with the dimple if they did anything. A FB poster who claimed to work at Cummins says he couldn't be specific but that it has a different name internally than CP3 and made mention of the story we all heard that Cummins was the one that forced FCA to change it.

What a show.
 
Epsilon Plus said:
After reading about how the front cover and maybe timing gear and some other stuff is different I could see them just TSBing the asym pumps with the dimple if they did anything. A FB poster who claimed to work at Cummins says he couldn't be specific but that it has a different name internally than CP3 and made mention of the story we all heard that Cummins was the one that forced FCA to change it.

What a show.
Click to expand...
Yeah, I really don't think they're going to be a retrofit through the dealership type deal in the event of a CP4 failure.

I feel that the internal remedy for the asymmetrical pump is going to be the symmetrical pump so I'm curious to see how those play out, I don't think I've heard of any failures on those yet. My guess is that based on lead times for design, testing, etc they would have had to start testing this new pump about a year ago. As I mentioned my contact at Ram couldn't identify the new pump and I'd put money on it that it is not exactly the same as the CP3 although it looks it externally.

I don't necessarily think this is a sky is falling scenario. Keep in mind people don't head to the internet to say how great everything is, it's usually to look for resolutions or to complain. The CP4 obviously has its issues as has been seen but I'm willing to bet based on the total amount of trucks on the road CP4 failure percentages are probably lower than people think, obviously the catastrophic failure that it can cause is concerning.
 
Hopefully the new pump will be an oem stroker type cp3 which would be amazing, can’t wait for a reputable aftermarket shop to open one up. If anyone hears of the name Cummins calls it please let us know, also epsilon what did you mean by “hair trigger” pump above?
 
It does make you wonder....if they can bump up torque again and now make 1,075 lb/ft AND meet all emissions requirements...why the hell did they switch to the CP4 to begin with??
 
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