Do I Have A Bad Injector??

[CBari]

Obviously I Know That You Can't Diagnose My Problem From A Post But A Little Help In The Idea Department Would Be Appreciated.



Here Is What Is Going On.



After Truck Reaches Operating Temp If You Stop At A Stop Light Or Stop Sign Truck Runs Rough. No Smoke What So Ever From The Exhaust. Has Slightly Noticable Knock. From 1300-1500rpm While In Gear Any Gear Truck Has Loud Knock. After 1500rpm It Goes Away.



I Thought Clogged Or Dirty Injector So I Drained The Filter Ran Filled It With Seafoam And Put The Rest The Can And One More In My Aux Tank With About 5 Gallons Of Fuel. I Ran The Tank Out And The Knock And The Rough Idle Was Gone.



Pulled My Trailer The Next Day About 20 Miles Across Town (10k Trailer) And The Knock And Rough Idle Is Back. Still No Exhaust Smoke At All Power Seems Ok, And Egt Are Where They Always Are.



By The Way This Is On My 03 With The Juice Off, It Has Never Been Above Level 3 And Only On Level 1 With The Trailer. Truck Has About 80k On The Clock.



I Know That I Am My Own Warranty Station Just Trying To Decide Which Way To Start Looking.



Thanks For Any Help.

 

[jjdiesel]

It does sound like a carboned-up injector. I've had 3 of them. Sounds like your on the right track with the cleaner in the fuel system. I would keep trying a few overdoses of cleaner. Wonder if the Edge pressure increase cracked an injector? Something to think about. Hope this helps a little

 

[Rams-n-Hogs]

Sounds like a carboned up injector to me, too. When I pulled mine the other day to swap nozzles, 2 of mine were carboned up, one of them to the point the needle was stuck in the tip. My idle was slightly rough, also, but not any more. I will be running some sort of additive from now on, especially with the switch to ULSD.



Jim

 

[Bandit1]

hey jim i think he needs a cap, haha

 

[Tryingit]

Run some Power Service, grey bottle (purchased at Walmart $12. 00 gallon) everytank. I've used 16oz with 4oz Marvel Mystery Oil since my second tank (after noticing a knocking sound). Never have a problem since (now with 38K. )

 

[Buffalo]

I had a similar knocking sound from idle up to about 1400 rpm when you put any kind of load on the engine.



I, also, read about the carbon build-up causing this kind of problem & the fix was running an additive or running the crap out of the engine to blow off the carbon. I tried the additive & it worked, for me. Previously, I had taken the truck to the dealer complaining about the problem. They tested it according to DC's proceedures & it passed even though the engine sounded like one injector came out of a pre-HPCR engine.



Trying an additive while towing may solve your problem.



Good Luck.



Joe F. (Buffalo)

 

[CBari]

Thanks For The Info Guys



I Have A 500 Mile Trip Make Tomorrow With The Lq Horse Trailer That Should Be Load Enough To See If The Additive Will Make A Difference.

 

[jjdiesel]

That sounds good! Make sure to report back and let us know

 

[CBari]

Here Is Some Of My Findings.



After 250 Miles Of Pulling About 11k Half Flat Land Half Ozark Hills, J/a Set On Level 1. Truck Seemed To Run Fine Only Heard The Knock When Rpms Where 1300-1499. Had Plenty Of Power Egt Temps Never Exceeded 1175 Pre Turbo Only Saw That Temp As A Peak While Climbing A Larger Hill.



While Spoting The Trailer With Foot On Brake And Truck In Gear The Truck Would Knock Bad And Idle Rough, But If You Put It In Park The Truck's Idle Smooth Out And Was Normal.



Had Pretty Much The Same Results While Driving Around Empty Though Town. The Only Thing Interseting That I Noted Was That It Only Knocked In 1300-1499 Rpm Range In The Truck Was Under Engine Load (i. e. Accelerating On Level Ground Or Going Up Hill) If You Were In That Rpm Range On A Down Hill Slope No Enginge Knock. Also Sitting With The Foot On The Brake At Stop Light The Idle Was Awlful Rough.



I Also Noticed While Sitting In A Parking Lot That Egt Were About 100 Degrees Higher While Sitting With It In Gear And Foot On Brake Than They Are With It In Park. This Is Problem Normal But I Just Noticed It.



Anyhow On To The Return Trip Trailer Is Heavier As I Now Have Picked Up 2 Horses Probaly Close To 13. 5k Now. Half Way Home I Notice That The Knock Apears To Be Gone And The Rough Idle Is Almost Completely Gone. Got In Real Late So I Left The Truck And Drove My Other Truck This Morning To Work I Will Un Hook The Truck Tonight And Drive It Tomorrow And See If It Is Better Or Not.



Just Wanted To Keep Ya'll Up Dated



Thanks For The Suggestions

 

[drewRoberts]

I also find if I start having a slight knock I find a long steep hill and floor it, she pushes some good smoke, not black, just a good grey haze since I'm stock. but usualy one or two times of getting and holding the boost pressure to 35# and egt's above 1000F for a little bit gets rid of the knock.



been useing 16oz PS and 8oz MMO for 28,000 touble free miles