Author Topic: 2004 3126e HEUI  (Read 654 times)

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Offline 3126E Guy

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2004 3126e HEUI
« on: March 25, 2019, 07:41:10 PM »
In hearing a pulsation noise in my engine I began to diagnose. Found the "noise" was coming from the HEUI outlet tubing with my stethoscope.
In dead head testing the HEUI pump pressure my test hose has an extreme pulsation/vibration. Acts like one or more pistons came off a shoe. The pressure gauge is glycerin filled 0-5000 psi and oscillates to the point of not being able to really identify hi/low pressure data. If I connect the hose from the pump outlet to the head port, rather the steel tubing, the noise level with engine running sounds like a machine gun. With the steel tubing the noise is reduced. I understand the phasing of axial piston pumps and the affect of disconnected piston to shoe failures and this seems just like that condition.

Has anyone completed a dead head test to find this pulsation/vibration on a test hose? Is the pump volume output enough that if one piston became disconnected it would still provide adequate oil to the injectors? The engine runs, no codes?
Any opinions before throwing $ at this would be appreciated.
Thank you

Offline David.e.atherton

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Re: 2004 3126e HEUI
« Reply #1 on: March 25, 2019, 08:46:09 PM »
Guy3126E, with your 3126E a engine s/n number is a must in order to assist you. Second question
do you have the new style Heui pump. Understanding there is a reason as to why before I get
started there are several different 3126E models each different build and signed a serial number. In providing technical information and not options, lot of time is wasted and incorrect
Information is passed along to the Diesel Club membership without correct information to
start with. Ask Dave, Dave Atherton Retired Cat Mechanic.

Offline 3126E Guy

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Re: 2004 3126e HEUI
« Reply #2 on: March 26, 2019, 05:25:33 AM »
Hi David,
Thank you for the reply. Being at work at this time I will need to forward SN when I return home. However, this is a 2004 3126e with newer style HEUI in a FL RV chassis.
I cannot locate a parts breakdown to determine IF the front bearing is a roller of ball and could possibly be the root cause or a possible gear issue. May I ask if you have experienced this before and what was the root cause?
I'm just trying to "prove on paper" before R&R.
I can and will get you the SN later today.
Thank you!

Offline David.e.atherton

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Re: 2004 3126e HEUI
« Reply #3 on: March 26, 2019, 06:28:20 AM »
Guy3126E, yes kinda understand little about this engine. One thing this engine is lot
different than other Diesel engines where being schooled up on how it operates is very
Important. Getting the engine s/n will pull up the build and engine spec’s at shipping of the
engine systems. Have you ever pulled a oil sample of the engine oil and understanding
how this can aid in pin point root cause of what is going on. When I receive the engine
Information I can start in on your problem. Ask Dave, Dave Atherton Retired Cat Mechanic

Offline 3126E Guy

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Re: 2004 3126e HEUI
« Reply #4 on: March 26, 2019, 09:15:25 AM »
Hi David,
Ser# is HEP43883. Being schooled is a great thing. That's why guys like you are an important part of sharing the knowledge.
This engine has been pampered: 5K oil changes with CAT filters, oil tests completed once a year by Cat with NO signs of out of allowable limits. 49.8k miles on her. I find it odd that an axial piston pump creates this much pulsation without some form of internal issue.. Does it decrease with higher rpm? Yes, but not by a large amount. I have completed the dead head test on this engine as verification after the IAP sensor proved defective,spring of 18, and it did not have this pulsation and ran perfect . Same test hose and gauge both times. At that time is was a low tone buzz on the hose. The engine performs well now except the pulsation noise can be heard all the way up front while driving. Just want to avoid a catastrophic failure of the pump and taking out injectors.
Thanks and in hopes to be able to resolve this condition.
Jim

Offline David.e.atherton

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Re: 2004 3126e HEUI
« Reply #5 on: March 26, 2019, 10:58:45 AM »
Guy3126E, the first order of business is warm engine up and pull oil sample and get into a
Caterpillar service shop to get oil sample readout. Second is there any check engine lights
On dash while engine is running. and power loss or smoke at exhaust. Sounds like possible
Problem is located in two areas. Injection Actuation pressure regulator ( location inside the
housing of Heui pump and is non-serviceable and requires removel of Heui Pump exchange
that has Injection Actuation Pressure Reguator inside housing. Looking at Aprox $ 2,300.
and deduct $ 600.00 pump core charge..the only thing you have indicated is the noise but
nothing on performance running or any check engine lights or flash codes. But let’s look at
The easy things first . Go to your engine oil cooler ( location in front of engine oil filter ) than
Looking at engine oil cooler on top corner you will see a 20 mm hex on a plug fasten into
engine oil cooler. Remove that plug and behind that plug and spring there is a plastic check
valve that may be sticking or partly broken. There is also another check on the bottom of oil
cooler also. Same as the top ( cap, spring, check valve. )Applying desk top diagnostic in case
of troubleshooting is not going to work and reading various forum unless someone can provide
factual technical information you are wasting your time. What is your engine oil pressure
running. Unless you have a code of 164-11 or a code of 42-11 is a good indication your problem
Is not located at the Heui pump. Ask Dave, Dave Atherton Retired Cat Mechanic

Offline 3126E Guy

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Re: 2004 3126e HEUI
« Reply #6 on: March 29, 2019, 01:49:10 PM »
Found loose drive gear in HEUI. Gear and shaft damaged beyond use. Replaced with reman unit and purrs like a kitten again.
Thanks for your opinions.
Jim