Problem- At idle, there is a faint knock-knock-knock sound coming from the drivers side of the truck. I ran injector cleaner through the truck with no help. Oil is good, pressure fine. Truck was serviced by reputable tech and he said that the truck ran great.(97,000 by the way on 2001 F-250.) No leaks, no other problems. I took it to another Ford dealer and they said they could not hear it even though I can. The guy also said to just drive it until the wheels fall off, 'cause new injectors are $400 a piece, not including labor (way to high?.) So, I live very close to an International dealer and brought it to the service guys. He came out and said that he could hear it, but that when you have a bad injector it is much louder and that I should just drive the heck out of it until it goes bad. My problem is, A- what kind of damage can I cause, and B- what is a fair price to have an injector installed, and C- Should I just turn up the stereo? Thanks for your help, I know of no better place for info-

The international guy also said that injectors are $350-$400 as well

 

I have a 00 and have the same concern. Just had mine in for an oil change and I swear it wasn't there before.

 

Do a search for "fuel cackle". Sounds like that could be it.

 

I have the same dull knock. It runs just fine, actually real fine. Sometimes it seems to be a little fainter than others but I can still hear it, annoying as hel. I just live with it. I want to do the crossover mod. I'm hoping that will help. If you find out the problem post it , I'm sure there's a few of us that would like to know. thanx.

 

i sent in a post about this problem about a year ago, and i got many replies saying it is engine cackle. the knock you are hearing is coming from the #8 injector. ford says it is ok for this to do it. i guess it is some kind of long lead injector?? anyways, the knock still comes and goes for me, i just live with it, and my truck runs great. drive it like you stole it.

 

The crossover mod MIGHT fix the knock. I've done all the mods: Hutch mod in the fuel tank and elimination of all the o-ring connectors on the intake side of the fuel pump. Redo the fuel supply to the rear of both cylinder heads so that #8 gets all the fuel it can handle without any air mixed in. And install the crossover hose. It didn't stop the knock but it made the overall idle sound much smoother and quieter. And a little more power to boot. Lot's quieter operation on the freeway. What made the most difference on my idle knock was a treatment made by Lubro Moly for Mercedes Benz diesels. It's called Diesel Injector Purge. It's basically a strong cleaner that removes all the deposits from the injector tips. I hardly ever hear the knock anymore. The engine's diesel clatter is now just about perfectly even on all cylinders and it has a glass smooth idle.

 

Thanks to all. I guess I will continue to drive the heck out of it and see what happens. The truck makes great power so I guess there is no need to worry. If it gets worse I will let you all know. Thanks

 

my 7.3 powerstroke knocks loud at idle but quite on highway. dealer said I need a new motor I dont believ them what do I do?

 

Kwick--I've come across alot of treatments that I consinder "snake oil". Most of my experience is in gassers, but every now and then I come across one that does what it says. Sounds like you've found one that actually does what it claims. Is it something you can get and use for yourself? Do I have to bribe the Merc. dealer? Blah, blah. You know what I mean.

 

You can buy it here: I am a customer of thiers also. What you do is to remove the inlet and outlet hoses from the fuel tank and stick them in the bottle and run the truck until the product is used up. You'll be surprised.
Recommend getting 4. Drain the fuel bowl. Pour all four containers into a larger clean container of your choice. Close the fuel bowl drain and start the truck. Run the engine until the product is used up. Reconnect the hoses, pour whatever is left into the fuel tank. Restart, test drive and grin.

http://www.bowwowseattle.com/catalog/lubro.htm
DIESEL PURGE - THE STRONG MEDICINE FOR SICK DIESELS
Properties: Designed and formulated for simple on the engine cleaning of clogged injectors and for restoring good performance. Contains a high level of detergents to unclog the injectors and to restore the right fuel spray pattern. Raises the fuel ignitability (cetane number) for an immediate improvement of acceleration, lowering exhaust smoke and power response.
Benefits: Improved starting, idling, response and acceleration. Reduction in engine noise and injector clatter. Reduction in visible smoke, particulates and other exhaust pollutants. Improvement in fuel economy, reduction of break downs and repairs. An excellent preparation for the smog test.

 

My 02 has had that knock since the day it was new. I have the HPX mod, no change.
Sounds like it's coming form the drivers side and like someone is taking a hammer and tapping the alternator. Quiets down a bit after oil changes and higher rpms while cruising.
Blackstone oil analysis are running below the averages for my mileage and oil change cycles. I have 50K on it with no problems.

 

Mine started after my injectors got changed on warrenty. It seems to come and go. I know what it is and real don't think about it much.Just drive your truck and enjoy. Eckart

 

Thanks Kwik, I appreciate the info.