The new C15 acert engine

Valley Springs, CA

#606 Mar 2, 2012
A few months ago I changed the thermostats from the 195* to 180* I had to use the cummings ones because you cannot get anything but 195* from cat. I had to use the o-rings from the cat ones . It made a good difference in temp. likes to run at 185 to 190 now. It will still go up to 215* pulling hills until you switch the fan on manual.Dont run me over on the highway though because I'm the one only going 57mph . Dont care if I get there late I'm getting 6.3mph . 1300rpm
don waldron nj

Jersey City, NJ

#607 Mar 16, 2012
mike wrote:
IíM having problems with a Cat C 15 the manifold gasket between the turbo keeps blowing out. We have replaced the center manifold and put on a new turbo but it is still blowing out at high altitudes
It's not the altitude It's the gaskets themselves their made out of regular metal ,when the should be made out of stainless steel ,according to cat own inside bulletin !!! Should be a recall nut they won't costs money ,I have 3 c15 acerts bought new and replaced them 4 times to date ,and three turbos because of the failed gaskets ,they break apart and go right into the turbo !!! I'm replacing a set tommorw that is only 13 months old and 30,000 on them ! The truck only has 292,000 total need to call cat and start bitching ,or a lawyer !
don waldron nj

Jersey City, NJ

#608 Mar 20, 2012
Chris Young JAKE BRAKE wrote:
I have a 2006 acert c15 and it is total junk!!!
250,000 engine ran away due to turbo failure and burnt whole engine up.
200,000 miles later,#1 rocker arm breaks,and #6 injector busts filling my crankcase full of diesel fuel. 4 days later 2 more broken rocker arms,and another bad injector,I now have metal shavens in my oil. 1 burned valve,and cam shaft is scratched to hell!!!
DETROIT DIESEL is your best choice,for trucks that you cant get a detroit in,get the cummins ISX,their a die hard engine!!!
CAT'S SUCK ever since 2003 on
Chris that sucks ,cat had what I'll call I silent recall on the rocker arms ! They would update all the rocker arms only if one bent ,nice right ! I had it happen on 4 of my Kenworths mind you they only had about 40,000 miles max .FYI your turbo probably failed because of the excuse manifold gaskets ,their not like the old c15 s ..
Their is a tube welded to it ,the weld cracks and sends the pieces into the turbos ,go to a cat dealer and ask to see one and you'll understand! Also cat knows this and does nothing about it !! I personally lost 4 turbos do to this ..need more people to file a class action lawsuit ! Here's my email . [email protected]

Columbus, OH

#609 Apr 5, 2012
I have a c15 twin turbo in my 05 kw, I would like to do away with twin turbo and go with single one, any ideas?
Alex the CAT engine fan

Bellefonte, PA

#610 Apr 10, 2012
Don't take after EPA 2007 engines. They have problem with regenerations.

Marion, IN

#611 Apr 10, 2012
wrongway wrote:
I have a c15 twin turbo in my 05 kw, I would like to do away with twin turbo and go with single one, any ideas?
It can be done, but it takes some work. The Accerts use twin turbos to move more air & create a higher boost pressure, which works hand-in-hand with the IVA system (Intake Valve Actuators). The expense of converting it to a single turbo probably outweighs the benefits....

A single turbo for an earlier C-15 engine would work, but you'll have to reprogram the ECM with a new "profile" for the engine. I would use the profile for a 2002 engine (serial number beginning with 6NZ). You will also have to "disable" the IVA system, and replace all of the housings above the rockers, if you want the engine brakes to work. Use housings from a single turbo C-15. The way your engine is configured now, these housings contain two IVA solenoids & one jake brake solenoid. You can't just "back-off" the IVA solenoid pistons, because the entire system (jakes included) is operated by oil pressure, which is controlled by the IVA system. When you disable the IVA system, you also disable the jakes :(

The truth is, if your twin-turbo is properly tuned, it will out-perform the older single turbos. We have both engines in our fleet, and I've done extensive work on each. Good luck with your truck!

Lexington, KY

#612 Apr 11, 2012
Question; Can someone tell me what it takes to change an accert cat engine over to single turbo (03 6NZ) engine, I am going to change mine over for better fuel mileage dearing an overhaul?

United States

#613 Apr 18, 2012
Cat rocks get your p d i up grade thats performance diesel injection outa salt lake big mpgs and power like my old cats useta have pdi baby 720000 no problems at all

Hickory Hills, IL

#614 Apr 26, 2012
can some one tell me about a c-15 475 twin turbo with 1.1 mil miles will last long ? and what should i check in order to buy a good motor?
please response.

Marion, IN

#615 Apr 27, 2012
neil wrote:
can some one tell me about a c-15 475 twin turbo with 1.1 mil miles will last long ? and what should i check in order to buy a good motor?
please response.
Has the engine already been "overhauled" or had any major work done to it? If it has that many miles, and has NOT been overhauled, it will probably need to be done within the next 200,000 miles. If the engine serial number begins with MBN, avoid this engine. If it begins with MXS, it's a better engine & worth rebuilding.

Cats are the most expensive engine to rebuild, I've seen dealers charge 15,000 to 20,000 for an overhaul. If you're able to do it yourself, the parts can be purchased for approximately 5,000 or so.

In all honesty, I would look for a truck with a Detroit or Cummins engine that has less miles on it, if possible. You will get much better fuel mileage & repair costs will be less, saving you BIG money every day!

Chicago, IL

#616 Apr 27, 2012
thank you for your advice Ken .i will look into cummins or detroit.

Marion, IN

#617 Apr 29, 2012
neil wrote:
thank you for your advice Ken .i will look into cummins or detroit.
You're quite welcome! Good luck finding a suitable truck for your operation :)
Cat God

London, KY

#618 Apr 29, 2012
Well let Me start by saying, you are not the only one, these engines are to tegious to be in an on hwy application, I am a mechanic for a Cat dealership,
I was A technician in the shop and the shop supervisor took another job in the company to get away from ACERT Tecnology, as our shop done some of the testing on these engines, I was aworded the position of shop forman and began the battle of ACERT, alot of these engines were sold on because of the sucess of the 3406E and early c-15, I stayed with it for 5 years and my technicians were the best,they had learned more than anyone on how to get them to run, but problem being, the bolt on parts,dpf,controler,art head ect will not last, anmd the clean air intake from the dpf was a joke they pulled dirt in every engine,I could go on and on about this engine, it is just a poor product, now my side of the story, I took the abuse from the customer {and i understood why} but the problem was no support from caterpillar or the dealership, we are in a heavy haul area and these engines will not work dependablly in this area. I know alot of people in this area lost everything trying to haul with these engines, Now me being in a position of managment how could i recomend a product that i don't belive in myself ? well after asking damn near everybody in the company for help and receiving none I was perswated to take a job with the company outside the truck engine dept, this costed me abot $20,000.00 a year less pay but i would rater have my digmaty and not have to lie to the hard working truckers, or anyone for that matter,
The management in our branch has covered up so much stuff that it's hard to keep track of all of it, now i'am not sure but i have been told that the dealer ships swaping the acert engines out and installing older c-15 or cummins to keep the whole thang from blowing up on them and going o court
Due to me haveing no help or support my health has declined and i have made myself sick over these engines and watching my friends struggle trying to stay in bussiness with these inferior engines.
The cat God

Marion, IN

#619 Apr 30, 2012
What was the REAL purpose of your post? I find most of your story unbelievable, but I guess it could have happened. Yes, there were many problems with these engines, and I would not recommend buying one. However, if you truly KNEW what you were doing, then you could have made these engines perform properly, instead of watching your friends go broke!

I maintain a fleet of 35 trucks, 23 of which are twin turbo Acerts. We have 5 older single-turbo C-15's, 2 older N-14 Cummins & 5 newer ISX Cummins. The Acerts have 500 to 700,000 miles on them, with NO major breakdowns. Yes, I've changed the ECM configurations on all of them, and they average over 6 mpg. Keep in mind these engines are in W-900 Kenworths, which are not the most aerodynamic trucks, either. Plus, we're "Meat Haulers", so these trucks are ALWAYS loaded heavy, pulling running reefers!

The key to succesful operation of these engines is to physically inspect the valve train regularly, retorque the rocker arm hold-downs & adjust the valves, intake actuators & engine brakes at the same time. I pull the valve covers & inspect them on a 6 month interval. I also connect to the ECM every 6o days to review engine performance & check all of the operating parameters, as well.

I will agree with you on one thing...most CAT dealerships employ "parts changers", not "real mechanics" who thoroughly understand the engine that they are working on! Kinda sounds like the shop you described :(

If any of your friends are still running these Acerts, they can post ANY question here & I will be happy to provide the correct answers, or they can bring it by MY shop for a "tune-up" :)
Cat God

London, KY

#620 Apr 30, 2012
To the Guy that is dissatisfied with the ACERT , best advise, find a cheep truck or engine with serial # 2ds,1lw,2ws,550 hp or better a 1mm or 5ds 600 hp and have dynoed all and these are the ones that produce the advertised Hp, and with a little tweeking with some fls 11 and fts 7 and a program for breaksaver, and some 5232 injector cods, will move the hp up around another 50 hp on the 550 and around 75 on the 600, just heep an eye on the pyrometer, and back out a little on a real long grade, to prolong engine life (675 Big Dog )

Sacramento, CA

#621 May 1, 2012
Jason Rappold wrote:
how is this engine holding up now its been out for a couple years.In the market on buying new truck.Should be Cat or Cummins?Heard a lot of problems with Cat twin turbo
I heard cat was going out of business no longer making engines? Is that true?

Marion, IN

#622 May 1, 2012
chuck wrote:
<quoted text> I heard cat was going out of business no longer making engines? Is that true?
Cat stopped producing on-highway engines prior to the 2010 EPA mandates. The engines that they produced to meet the 2007 EPA mandates were a total disaster, and the DPF systems (Diesel Particulate Filter) systems failed constantly. Many owners of 2008 model year trucks with these engines couldn't keep them on the road, due to mechanical failures :(

All of the Cat Acert engines in our fleet were produced in 2006, and installed in the 2007 Kenworth W-900's that we run. These engines were designed to meet 2004 EPA mandates, and have been very reliable, for the most part.

NEVER buy a Cat C-15 manufactured from 2007 on!!

Lagos, Nigeria

#623 May 17, 2012
pls DynPro, am on hot seat and need help on using pwm potentiometer to control governor of the C32 cat engine, its a new one, thanks


#624 May 18, 2012
2003 c-15 475 horse boost usually runs 30-35 but latley was cutting out when temp got up to 200 so i had to run the fan all the time now it cut out at any temp any one now y i changed turbo preuusure tested ir to air changed thermstate and heat sensors what else

Marion, IN

#625 May 19, 2012
jesse wrote:
2003 c-15 475 horse boost usually runs 30-35 but latley was cutting out when temp got up to 200 so i had to run the fan all the time now it cut out at any temp any one now y i changed turbo preuusure tested ir to air changed thermstate and heat sensors what else
When you tested the air-to-air, was it done with a pressure-testing kit? Also, why was the engine running hot in the first place? Did it turn out to be that the thermostats were "stuck open"?

When was the last time you changed the air filters? Air restriction will not only cause an engine to run hot, it won't be able to develop proper boost through the turbo, either. Did you blow the dirt out of the "Radiator core/air-to-air core/AC Evaporator" combo in front of the engine?

When an air-to-air system can't properly "cool" the intake air, the engine temp will run about 10 to 15 degrees hotter all the time & the engine won't "boost or pull" like it should. We had a 2002 C-15 like yours that did just that, there was a small crack in the air-to-air aftercooler. I replaced the aftercooler, temp dropped, engine was boosting 35 again.

If you have all the temperature issues solved already, and it still won't boost or perform properly, maybe the problem is being caused by low fuel pressure. The only was to test this is to physically connect a pressure gauge to the fuel return line right before the fuel pressure regulator where the fuel filter housing is mounted on the driver side. It should be 75 psi @ an idle, and 100 psi @ 1800 rpm.

Don't pay someone to connect a "computer" to your system, they CANNOT tell the fuel pressure that way! Good luck with your truck :)

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