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Wayne, Journeyman
Category: Medium and Heavy Trucks
Satisfied Customers: 9532
Experience:  worked on, Gmc, Macks, Freight liner,Mercedes Benz,,Ford, sterling
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Cat 320C-LU smoking under load, new injectors have been

Customer Question

Cat 320C-LU smoking under load, new injectors have been installed and all pressure regulator seals replaced.
Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Expert:  Wayne replied 1 year ago.

Hi I'm Wayne

I will help you with this

what color is the smoke, bluish,white or black

let me know

Customer: replied 1 year ago.
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Customer: replied 1 year ago.
Black smoke
Expert:  Wayne replied 1 year ago.

Thank you for that

that can be 2 things,

restricted air intake

or injectors over fueling

I suggest to remove the air filter and see if it still does it

if yes, replace the injectors

I hope this helped you

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Customer: replied 1 year ago.
New air filter, hydraulic filter and new injectors been installed.
Customer: replied 1 year ago.
Engine runs fine with no load. Only smokes under pressure.
Expert:  Wayne replied 1 year ago.


I did not see the inj, replaced ,sorry

then that boils down to the hydraulic pump dragging

Customer: replied 1 year ago.
Not familiar with the term ' hydraulic pump dragging'. Please explain.....thanks.
There's more pressure on one side of the pump compared to the other.
Customer: replied 1 year ago.
Is this the end of your diagnosis?
Expert:  Wayne replied 1 year ago.


Sorry for delay , took wife to Airport , Mother passed away last night in Colorado

when I say the pump dragging is that it is loosing pressure

any when you mentioned more pressure one side to other

that is a pretty good indication

I hope this helped you

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