Cat engine operation question

[Dave Atherton]

Gentleman, forgive me for taking up so much space but there has been great input on a very
important subject that affects all of us. Clearing of diagnostic codes many thoughts on this subject
an well understanding diagnostic codes. With cars and pickups many codes come and go so a cheap
AutoZone code reader will clear codes and many people do just that. With your motorhome Diesel
engine I would suggest not clearing any codes until knowing for fact code is not active. Good case
in point end of BAC Farmington Rally. One motorhome had work preformed about month before
coming to Farmington and started to leave and check engine light came on. Owner returned back
to rally grounds and Dave connected Cat ET to his engine and pulled several logged event codes
that required attention. Owner talking with service shop that preform services month earlier and
the shop foreman wanted me to clear all codes so he could return home 500 miles away. In talking
with owner I really did not want to clear the code that I printed out because I would remove for
the next Cat service shop what had been overlooked with earlier repair. Long story short by not
Clearing the codes present and owner could return home, service at different Cat shop by having
Not cleared codes found several issues over looked and saved lot of money because information
was not cleared. Gentleman the point is our engines require trained mechanics to understand what
to do and yes information is not available on the internet as some may feel they can find.
Dave Atherton Retired Cat Mechanic

[Dave Atherton]

Gentleman, hate to keep adding problems but again everyone should be made aware of.
Aftermarket parts believe we touched on this subject but may we need to touch on this again.
Quartzsite, AZ. Camping on the BLM land and owner working on his motorhome and getting
caught up on repairs. Caterpillar C-9 replaced 2 injectors results of some generic code reader. Ordered
The injectors from Amazon and installed injectors says he saves a real lot of money. Dave got
called out on service call to that motorhome because the motor would start and run but run it
down the road at 45 mph engine would shut down to idle like it running out of fuel. Going through
fuel system troubleshooting problem it was determined problem had to be in the injectors just
installed.( this is where the look alike part comes into play.) that when I found out injectors were
Non-Cat. Removed 2 injectors from my Cat C-9 engine that I have for instruction and installed
In this owners Cat C-9 engine went for test drive runs out fine with the used Cat injectors. Removed
my injectors and suggested to owner to buy the correct Parts from Caterpillar. Going deeper into
What is going on, the diesel fuel go through the fuel rail and around each injector and returns excess
fuel back to fuel tank in front. ( cause of problem the screen at the injector opening Was about
half the size opening as the caterpillar injectors which would starve Engine of fuel above 45 mph.)
To this gentleman from up north he felt the savings out weight Caterpillar high cost. Than owner
wanted to buy my used injectors that I would not sell them because conflict  of interest telling a person what is wrong but just happen to have a part to sell you. Dave Atherton Retired Cat Mechanic

[Lee Welbanks]

Very well said Dave, don't be fooled by any engine part that states: "Just Like OEM Cat" the only OEM cat parts come from Caterpillar. I wonder what the end cost was for this guy installing  two non OEM injectors in his motor?

[Robin Goffrier]

Here is a follow up to my post on the Cat C9S Check Engine light and related issues. To review, the yellow check engine light came on about 500 miles into a trip 920 miles south to Indio, CA. The light would not reset, indicating an active issue. Then, about 300 miles out at an elevation of 7,300' the engine lost power 3 times in about 15 seconds but regained full power and ran fine for the balance of the trip down. (At no time did a red check engine light illuminate.)  I had a diesel mechanic, not from Cat, come to the RV park and run the codes. The first was an inappropriate response from the #2 fuel injector.  It would not reset and the light remains on.  He found a second code that would have given a yellow check engine light had it not already been illuminated from the first issue.  The second code was an inappropriate response from the turbo actuator. ( the power loss issue at the high elevation) That situation resolved itself and the light went away.  The closest Cat facility is about 75 miles away in Riverside, CA. That was in mid October of this year. So now we are back in Bend, OR having driven our tow home for the holidays.  This morning I visited with the Cat dealership in Redmond, OR where the coach is routinely serviced. They were most helpful and told me the specific code I gave them was related to the fuel injector monitoring system and would have no bearing on the operation of the engine, which runs fine.  The actuator code was related to the geometry of the tubo blades and may or may not be a continuing problem.  But in any case I was given a green light to drive the coach back to Bend in the Spring and have it checked out by them at that time.  That's what I know at this time.  Thank you all and particularly Dave for the great input.  And to all, a very Merry Christmas and safe travels in 2019.

Robin G