Injector knock
 

Hey could someone here please explain to me what injector knock is and how it sounds. I have a 2001 PSD with 211 grand on it. And about 3 months ago my truck started to white smoke at idle, took it the the dealer cause i thought mabey an injector went bad. He told me after 15 minutes, seriously, that my motor was trashed get a new one. And there somtimes was this awful sounding knock, louder than heck coming from number 3 cylinder the one the ford tech said was trashed. Man you would almost think a rod was knockin and she was gettin ready to grenade. So i started to investegate a little I changed my oil just the other day after 4000 miles about 3000 of those miles were driving with that knock somtimes it was quiet, and I cut my oil filter top off and looked at the element and there was absolutey no metal in it I was suprised. If a metal piece was knocking that bad there should be somthing in there. The truck runs just fine and i have all my power. I run a edge j/a and evo to by the way and i usally run with em turned up, but it runs the same when i put it back to stock. all my gauges read fine including boost and EGT. Its just im getting embaresed driving my rig cause at stoplights the white smoke starts to come back. But sorry about the long post I just wanted you guys to know all the info, I guess my main question is could my knock been injector knock and could a bad injector cause these symtoms. Any help would be helpful, Thank you Chase. P.S. all my valves are tight and rocker arms are solid and it burns barley any oil.

it is most likely air in the fuel- termed "fuel cackle" or injector knock. it is because the stock fuel system is "dead end" , which means any fuel that makes it past the fuel bowl outlet, has to go through the injectors. that includes the air in the system too. best thing to do is install a fuel regulated return system. im about ready to buy mine, im getting mine from ITP diesel i believe has the blue fuel lines. some guys here such as PSnut, Jtharvey and Kwikkordead have all done theirs' custom, and they claim they save about $150 or so. Lancer even did his with steel fuel lines. :-X22

www.itpdiesel.com

www.dieselinnovations.com

Ok but it seriously sounds like hitting a hammer on the side of the block. It only happens at idle and if its a compression issue why does it run so good above idle. I dont think its the fuel system cause this is the first sign of this white smoke after 200 and some thousand miles. Heck mabey my motor really is shot, but i prefered it wasnt, lol. Thanks for responding to my post Kris and have fun on your road trip. I was planning on driving down from Alaska to Nebraska this july but it looks like im flyin now. later Chase

You need to find a different dealer....one that will tell you which injector is bad and replace it.

jeezzz...no kidding Scott!....these Stealerships never cease to amaze me with what they try and get away with:-X15 .

I will, problem is that this is Alaska and my next dealer is in anchorage which is 150 miles away but thats all good. Hmm so the term injector knock is just somthing with fuel airation in the injector causing the knock or can somthing else cause this cause its damn loud and it definetly coming from number 3, the one they told me was bad. Also can a bad injector replicate the same symtoms of a bad motor?, wow i have too many questions. later Chase

U have something going on with an injector, maybe an O ring or maybe a bad injector. No "bad motor" if u ask me. Maybe some bad fuel. Like Strokin' said airation will make things real noisy.

fuel cackle is normally described as someone hitting the block with a small hammer. so yes i firmly believe you have a fuel problem. specifically #8 cylinder which gets starved for fuel on a stock system. i am trying to find the link to a site, with a video clip of a guy walking around a truck while idling that is experiencing fuel cackle. it's very prevalent. anyone have that link bookmarked and can help this poor fellow?


usually a bad motor will either shoot something out of the exhaust, blow up and shoot something out of it, or something like that. i have never heard of a lifter knock or a valvetrain rattle from a powerstroke that causes it to take a dump. 90% of the time it is just a simple air-in-fuel system. you can start the process by doing the "in-tank and prepump" mod system that eliminates the most possible air entry and entrainment spots in the suction side of the pump.

thanks, i certainly will have fun. scrambling tonight and tomorrow morning to get parts ordered so i have a bunch waiting when i get back. }>

Kris, don't forget he mentioned excessive white smoke on occaision.

i would have to say a bad injector as he proposed along with air in the fuel. i dont think only one injector gets the air. it also may be possible that this injector was destroyed by air entrainment. over time, enough air has been injested and the injector wears out due to lack of lubrication, etc. i would assume a low injection pressure causes the fuel to not burn, as if starting up on a cold morning with bad 'plugs. the fuel exits unburnt, and just the white smoke is noticeable when enough fuel is injected. run a cylinder contribution test, see which one is pushing it's fair share on the crankshaft.

has anything such as small particles of dirt been injested in the engine? may be possible (slim chance) that something hit the injector tip by chance and screwed that up, broke off the nozzle point, causing the fuel to just dump out rather than atomize into smoke. --pull off the intake boot that goes into the side of the compressor side of the turbo. check to make sure the blades on the wheel are straight and smooth, knife sharp. keen eye for cracks or pits/bent edges of the compressor wheel.

just some things to think about and ponder or check out.. i may be way off base but it happens.

Check your fuel pressure. Low fuel pressure will cause white smoke and fuel knock. If your fuel pressure is up to spec (40 psi but best at about 60 psi) Then you probably have an injector going out. How often does this occur? After long pulls heavy load? I have seen very fine hair line cracks develope on injector tips that allow for non atomized fuel to enter the combustion chamber. This causes heavy white smoke at idle with traces of blacvk smoke, a rod knock type sound and usually clears up at higher rpm. Causes of this condition are low fuel pressure, high mileage injector, an improper bleeding of the fuel system after a repair was made. You can isolate a cylinder with this condition by measuring the exhaust manifold temp while it is smoking and carrying on. It will be the cylinder with an exhaust temp that is much hotter than the cylinder next to it. Typically 75 degrees hotter. Cackle should not be confused with fuel knock. Cackle is a whole lot quieter, doesn't produce smoke, and doesn't make you think a rod will be coming out the side of the block.

OK I looked at my compresser wheel and its pretty new cause i swapped the stock unit for the wicked wheel so yeah it looks perfect and it spins freely. Im guessing ford did a cylinder contribution test cause they said cylinder number 3 was the problem. and when i was under that valvecover i unpluged the number 3 injector and sure enough no smoke, but it was not clicking that loud that day so i couldnt tell if the knock stopped. Also there was a small amount of oil in front of my compresser wheel could that be the sign of extreme blowby. I do not have the CCV mod done. Again I thank everyone who is trying to help me out this site is awesome cause of the people here. Later Chase

blown99, dont confuse fuel cackle (air in fuel) with fuel knock (overly fueled engine on the verge of hydrolocking). i saw a cummins engine in a superduty at spring fling have fuel knock when they got on the throttle before boost came up. tons of white and grey smoke. sounded bad too. i dont think you are overfueling.-. do you have the ability to replace the injector? im not questioning your ability, but i can show you some sponsors that sell individual OEM injectors if you want to DIY.

yes i could replace the injector myself im sure, I wish there was a way of finding out if the injector was bad before buying a new one, i would prefer not to drive to another city im just afraid to drive it long distance. But yeah let me know where I could get one Kris and I will highly consider it, thanks Chase.

http://www.dieselinnovations.com/di....products&cat=2

there ya go, $284 a piece. not sure about core, think you have one. you want an AD code.