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Tim
Tim, Foreman
Category: Heavy Equipment
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Experience:  23 Years Heavy Equipment and Truck Repairs Shop and Field in the Minning and Construction Industry
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3126 cat engine with low oil pressure..full throttle..idel..shutdown

Customer Question

i have 3126 cat engine with low oil pressure in normal operated temp. and after full throttle and then back to idel speed the engine is shutdown and can not started .

regard
anwer
Submitted: 5 years ago.
Category: Heavy Equipment
Expert:  Tim replied 5 years ago.

Hello, Welcome to JA , My name isXXXXX will try to help. coulpe questions for you, how does the oil look and feel, any chance you have fuel in the oil, or coolant( doesnt always turn milky) . Have you hooked up a manual gauge to see the oil pressure, and are we talking about engine oil pressure, or heui pump oil pressure, please reply with ser# XXXXX let me know

 

Tim

Customer: replied 5 years ago.

dear

the oil was change and the oil level is ok, oil filter changed, fuel filter changed and there is no oil in the cooling system or fuel.

when we start the engine and the RPM is 800, cooling temp.is around 30C and the oil pressure is 50 psi. when the engine is in the operation temp. 80-100 C and the oil pressure in this time is 25-20 psi and the warning low oil pressure light is on with RPM 800 and the engine still running after that we increase the engine speed to full throttle and back to normal RPM the engine is shutdown and can not started immediately but after 2-3 minuet the engine start normal.

this problem happened only when the low oil pressure light on and when we reduce the speed to ideal speed only.

but if the RPM is 800 for along time until the oil pressure is less thane psi and the warning low oil pressure is on, the engine still running with no problem

 

regard

anwer

Expert:  Tim replied 5 years ago.

Hello, Thank you for that, just to be clear I wanted to make sure there was no fuel or coolant in the OIL, not vise versa, if the oil is new, the correct weight , and not fuel diluted then that is good. Fuel or coolant diluted oil will not pump when it warms up. Have you verified with a seperate manual gauge that the oil pressure is infact low? also, you are saying that the light is comming on and showing 20-25 psi as low oil pressure at 800 rpm, at operating temp? Last please supply your engine ser # XXXXX there are many uses of the 3126 engine.

 

Sorry for the questions, just want to make sure I am looking at the correct problem.

 

Tim

Customer: replied 5 years ago.

dear, i am sure there was no fuel or coolant in the oil, and the oil pressure is low.

knowing that the engine is fitted the cement unit used in well oil services jobs, i mean we have only tow different engine speed (ideal speed 800 rpm - full throttle 2500 rpm). as u know the fuel injectors is operated by oil pressure so when the engine is at full throttle 2500 rpm and we need to decries the speed to ideal, the engine is shutdown cause of the oil pressure in this case can not effects to operate the fuel injector (no fuel inters the combustion chamber).

engine model:3126 cat, S/N: 9ZR0-3145, engine hours: 296 h.

 

regard

anwer

Expert:  Tim replied 5 years ago.

Hello, thank you for that yes I Know that the HEUI needs oil pressure to work, but the oil sending unit is part of the inputs the ECM reads to control the Heui . to make high oil pressure for injection. click Here is the trouble shooting needed, please let me know what you find.

 

Thank you,

Tim

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