Need some help with a Knock!

[RobertP]

About three weeks ago I had and injector body crack while driving. Pulled off to the side of the road, after noticing a bad fuel smell. Found the oil level way over full and the under side of the truck soaked in fuel and oil, from the breather. Pulled the injectors sent them out. Replaced the cracked injector body and got some new nozzles put on. Reinstalled all of the injectors changed the oil. (Drained out about 7 gallons of oil and fuel mixture) started the truck up idled perfect nice and smooth no smoke at idle at all. Drove up and down the street noticed a what seems to be a timing induced knock. Starts as soon as there is a load on the engine and is completely gone by 2000 rpm. Programmed the ecm back to stock the noise lessened but was still there. Once again I sent my injectors out to have them tested all tests come back golden. (Again I have to thank industrial injection for putting up with me through all of this) I got my injectors back again today and installed them. Knock still there, and gets worse wheni put the program back in the truck. Checked all sensors for proper connections all good. Drove the truck home runs great still has a ton of power runs and idles great still. Just have this annoying knock from let's say 1300-2000 rpm then it's gone. im at my wits end with this thing. Oh yeah one more thing I put a new stock cp3 on thinking maybe that could be the cause. Any and all info would be appreciated. Thanks Robert. Feel free to ask any questions im at my wits end with this knock.



sorry for the long post!

 

[rbattelle]

Maybe a bad rod or main bearing from running with the fuel/oil mix?

Ryan

 

[RobertP]

Maybe a bad rod or main bearing from running with the fuel/oil mix?



Ryan

i was thinking the same thing until i downloaded the older smarty file from april 23rd. and stopped running the beta. the knock is almost gone. i used to hear it from 2nd threw 5th when shifting at low rpms. now i only hear it in second when first taking off. i think it was from running too much fuel and pressuse with the bigger injector. i will know more tomorrow.

 

[Red Ram]

Rob reset your tone ring too stock (retard timing)

 

[RobertP]

Rob reset your tone ring too stock (retard timing)

good call on that one thurmon! i will try that tonite.



well on the way into work this morning i noticed that with the new flash that the knock is less pronouced but is still there. please keep the ideas rolling.

 

[WPeschel]

Rob reset your tone ring too stock (retard timing)

I hate too ask a dumb question but what the heck is the tone ring??? Is it the Silencer ring??

 

[RobertP]

I hate too ask a dumb question but what the heck is the tone ring??? Is it the Silencer ring??

no that is the ring behind the balancer that the crank sensor take its reading from. insted of buying a modded sensor i just modded my tone wheel.

 

[RobertP]

well today i put it on the DRBIII ran the injector cut out tests and cylinder performance tests. all tested good. cylider performance came back perfect. funny thing after i drove the truck while running the injector cut out tests. the knock is gone. not there at all. its got me more confused than ever. but happy that the knock is gone.

 

[mberry]

Robert,

I get some pretty nasty injector noise if I turn up my TST past 3/3. Sounds like a 7. 3 Powerstroke on a cold morning if there's little or no load. The larger the load, the quieter they are. If I remember correctly, it's the advanced timing or something like that.

 

[RobertP]

Robert,



I get some pretty nasty injector noise if I turn up my TST past 3/3. Sounds like a 7. 3 Powerstroke on a cold morning if there's little or no load. The larger the load, the quieter they are. If I remember correctly, it's the advanced timing or something like that.

thats very good to know. it was just very unsettling hearing my engine knocking like that. but yes that is the sound i am refering too. like and old 7. 3 on a cold morning.

 

[steved]

Umm, did you TIME the CP3 when you installed it??? That is a very common source of timing "knock"... its actually the timing gears "slapping" because the pump is out of synch...



There have been a lot of guys that have had CP3 slap and by removing the timing gear from the pump and reindexing it causes the noise to lessen or go away...



steved

 

[RobertP]

Umm, did you TIME the CP3 when you installed it??? That is a very common source of timing "knock"... its actually the timing gears "slapping" because the pump is out of synch...



There have been a lot of guys that have had CP3 slap and by removing the timing gear from the pump and reindexing it causes the noise to lessen or go away...



steved

thats something that i will be checkong this weekend. i will be replacing the cp3 with a modded one so i will make sure i time it.





on the way into work again this morning the knock was present. it was very slight i really had to listen for it. i could not hear it over the radio at a very normal level. so whatever this noise is it has gotten a lot better since the first time i heard it. but knowing that there is a knock somewhere in my engine is driving me nuts.

 

[Bandit1]

robert, just steal the motor out of wades truck and drop yours in his, he wont ever know. or i got an extra 12v you can drop in the 5500!!

 

[RobertP]

thanks josh. the dang thing still runs great though.







during lunch i ran an oil pressure test. oil psi at idle-55psi cruiseing in second and third is about 75-80psi. my shop forman was out on the lot and said it sounded like a rod knock. then i took him for a ride and it would not make a noise. if it were a rod knock it would be consistant. am at still at a loss on this one.

 

[rbattelle]

during lunch i ran an oil pressure test. oil psi at idle-55psi cruiseing in second and third is about 75-80psi.

Those numbers seem a little high. Were these on a cold engine?



Ryan

 

[RobertP]

Those numbers seem a little high. Were these on a cold engine?



Ryan

yeah. the engine temp was about 125 when i first started. ive always noticed the noise worse in the morning. or when it was first started after a period of time.

 

[RobertP]

just in case this became a question i have been running amsoil with a bypass since 19,000 miles. i have 59,000 on it now. in that period of time the oil and filter have been changed 4 times. ive always been one for over kill. then just recently i changed the oil three times since i have fill the crankcase with fuel. but that was with just regular dino oil, until yesterday i put new fresh amsoil and filters on.

 

[RobertP]

i dont know if this means anything but today on the way to the fuel station, knowing i was nearly out of fuel. i could hear the FASS pump surging like it always does when i get low on fuel. the knock went away. about three miles later the low fuel light came on, i put about another ten miles on it before getting to the fuel station. the knock stayed gone. i even tried to make it knock, by running in the rpm range when it would normally knock really bad. between 1500-1900 rpm. fill up with fuel, only had the chance to put about 5 miles on it and the knock was still gone.



could all of this just been bad fuel? i have fill the truck up multiple times since the knock started this is the first time i ran it really low on fuel? will post back tomorrow when i get some more miles on it. thanks Robert

 

[MMeier]

Almost sounds like my rig since injectors went in it a few weeks ago. Started a thread on this also.

 

[RobertP]

Almost sounds like my rig since injectors went in it a few weeks ago. Started a thread on this also.

yeah i saw that. i had a bad injector and replaced the bad one had all of them tested and reinstalled. ever since then i have been fighting a knock. i actually took them back out and sent them back in to have tested again and all came back good with the injectors. reinstalled them and have been fighting this knock since. truck is running perfect and performs pretty well. just the knock between 1500-1900 rpm. until tonight.