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Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 5558
Experience:  Owner at DJ Wilson
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Ihave an n14 cummins in my peterbilt making a loud hammering

Customer Question

ihave an n14 cummins in my peterbilt making a loud hammering noise trying to figure out possible issues
JA: Thanks. Can you give me any more details about your issue?
Customer: just in between first and second head puff of exhaust is released on start up runs fine pulls fine temps ok pressure ok .. just loud hammering noise
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Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Customer: replied 1 year ago.
just waiting for the answer or a response?
Expert:  Daniel Wilson replied 1 year ago.

Hi my name is***** will be glad to help. What is your engine serial number and are you getting any fault codes? This could be a mechanical failure like a rod, piston, push rod, rocker arm etc or most commonly if all those check out ok is a faulty injector or Jake brake problem. Is the check engine light coming on and if so what codes do you have?

Expert:  Daniel Wilson replied 1 year ago.

Check the oil and filter for signs of metal/debris indicating a mechanical internal failure and if clean do an injector cutout test if misfiring to isolate a possible faulty injector or injector harness. Let me know

Customer: replied 1 year ago.
no engine light no fault codes oil and filter just changed no sign of any debris or leaks exhaust manifold and intake manifold just replaced all turbo gaskets replaced
Customer: replied 1 year ago.
serial number is *****
Customer: replied 1 year ago.
how do you do an injector cut out test?
Customer: replied 1 year ago.
runs fine no loss of power no other indication of an issue other than loud hammering noise ...louder when sitting at idle and the puff of smoke when first started up
Customer: replied 1 year ago.
just a rhythmic consistent hammering noise seems to smooth out a little when running at higher rpm
Expert:  Daniel Wilson replied 1 year ago.

Were any of the exhaust ports wet with oil/fuel for any cylinders? Using a digital temp reader take temps for each exhaust port looking for a cold cylinder indicating a potential injector problem. Then using noid lights from an auto store check for strong injector voltage for potential injector driver issues in the ECM or injector harness problems. If that checks ok then using Cummins Insite you can do an injector cut out test or unplug each cylinder one at a time and listen for a change

Expert:  Daniel Wilson replied 1 year ago.

A cylinder with little to no change is a problem cylinder

Expert:  Daniel Wilson replied 1 year ago.

Once you have isolated a problem Cylinder, remove that valve cover if the harness checked good and inspect the rocker arms and wiring for damage to the injectors

Expert:  Daniel Wilson replied 1 year ago.

Hi, Did you get this resolved or still need help?