I replaced all 8 injectors about two years / 20k miles ago and haven't been back under the VC since.
I recently read that the injectors should be re-torqued after XX amount of miles ?

Should I bother going back in? Any symptoms that I should be aware of.

Thanks.

 

blue exhaust on start up is what prompted me to re-torque mine.

 

If you start hearing a knock. Tug will be along to tell you.

 

No sign of that, Thanks.
I hear what I think is a knock, but it's always been there.

Tug will have me tearing down the top half of the engine with a jewelers monocle... JK....
I remember him having some issues with a loose inj. He'll point me in the right direction.

 

Owe Mai Gawd.

You don't need to go back in there under normal circumstances. Stinky, however, has a watch repair man for his mechanic/owner. I never needed a torque wrench before I did injectors, so of course I botched the job. As a reference, the book says 120 inch/lbs on the injector hold-down bolt. I've had uppers bolts work loose, so make sure the upper is snug before installing the injector. I learned to apply blue Lok-Tite, set my torque at 130 in/lbs, then start the truck and get it to operating temp. After that, retorque.

Some say a retorque after 1/2 hour does just as well, some use blue Lok-Tite and say don't retorque, and many don't retorque, use blue Lok-Tite, or even torque to 130 in/lbs and do just fine (as far as they know).

Symptoms:

Phase 1: You can hear a knock that can easily be mistaken for cackle. ( I can pick it out between 50 in/lbs and 70 in/lbs).

Phase two: The knock gets louder and can be accompanied with a "ting" if your ears can sort it out. You may get some haze and stink at this point, and bolt torque is likely below the 50 in/lb minimum. Once you are this low, you must replace the O-rings and copper washer.

Phase 3: Total disaster - banging and crashing and pinging. Exhaust, soot, and oil is going in the fuel rail and injectors, exhaust gasses are conspiring to melt and hammer your injector cups and O-rings, and the engine is missing/shaking. You need to install radar to find your way out of the fuel/oil fog bank... and when you emerge, there are your neighbors in their bath robes - leering at you.


I suggest you get curious before phase 3.

 

Thanks Tug. I'll investigate to give me peace of mind. It's just so hard to muster the motivation in this heat...

I don't hear a knock like in your video, just normal cackle I suppose.
It's been stinky since the swap to SS's.

 

The manual specifically says to lube the bolts with oil before torquing. I'm going to go out on a limb and say cleaning the threads enough to actually use loctite might end up causing enough friction to skew your torque reading and leave them, in reality, under torqued. My theory is that the bolts don't back out at all. I think what happens is the soft copper chamber gasket crushes and gives the illusion that the bolt may have backed out. Someday I'm going to test this theory by torquing a freshly installed injector with the bolt oiled and safety wiring it in place, then checking the torque at some later point in time. I might even go so far as to check the before and after thicknesses of the chamber gasket.

In the grand scheme of things it probably doesn't matter much. I'm sure when the injectors were installed originally they were torqued once and sent on their way down the line. I would like to know what's really going on with this phenomenon to satisfy my own curiosity, though.

 

ive recently been down this road as well. Last month i torqued mine as they were all loose and had been for some time. I had always suspected as such but after watching rich's videos and reading of his adventure i was convinced. I could just hear it, at first thought it was cackle, then it just didnt sound right. Drove it that way for a long time before fixing. After torquing the bolts back down the noise went away, the engine idled smoother, and i had better response (the new turbo wheel had a little to do with that as well). But just two weeks after doing this, i thought i was hearing the sounds of looseness yet again. Nah! Couldnt be. But after 3 wks i was convinced that was what it is, i can hear the same sounds again. Not as pronounced, but its there. Also it seems some of my response has gone away and i have heavy "cackle" when going from a dead stop. Once the engine warms up it gets better and cant notice. But with a cold engine, its definitely there. And like you Frank, i have yet to muster up the energy to do it again in this heat, at least not while im currently busy tending a leaking ac in the house with some termite damage. The injectors can wait for now. But im convinced that after only 3 wks after torquing, they are loose again. I suspect crushing of orings or washers to be culprit, because once things come to temp, its all good. Might be time to change orings and washers, but then why not change to SS's while doing that much? Most likely will go that route when the time comes. Will likely turn 300k on the factory sticks next week, and while they are still operating good, aside from the looseness, Im sure they are getting a lil long in the tooth so to speak....

 

That was my reaction the first five times. After about 15 rounds of this cycle, every noise on the truck has me popping the VCs to check torque. I did it in a parking lot recently just to satisfy my curiosity... and they were all good still. I've had four successful safety checks since I nailed it in February (many thousands of miles).

My hands have VC-pop muscle memory, and a casual pace has me at 45 minutes from hood pop to hood drop (for one side) - including cleanup and tools stored. All this with the tools in the truck. Add a 1/2hour to that if I do both sides at the same time.

Part of my problem was the crush washer. It took a number of tries before I realized re-torqueing with a warm engine helped with all but the #7 injector. #7 fought me several more times until I bought my 9th injector. Once I had a stick to swap out, that's when I discovered a rolled cushion ring on #7 - and that was my problem the whole time. Since I was the one putting the sticks in, I had to find a mirror to point at and growl "YOUUUUU!".

 

We have met the enemy and he is us.

 

LOL... sometimes I think that too.

I've been known to break things that aren't broke all in the name of preventative maintenance.

 

I know the manual says to use oil before torqueing and I believe that to be true with new bolts and fresh treads. But when you have a old bolt that has stretched bolt shank & treads I am a firm believer in a clean bolt & treads use loctite. When a bolt and the boss treads are clean using Loctite will act like a lube when it is still wet. Put some Loctite between 2 fingers and move the 2 fingers see if you feel friction. Years ago back when I rode bikes I got in the habit of using Loctite or safety wiring almost everything and most importantly torqueing to spec. Personal I use red loctite more than I should but it helps me to sleep better at night....OK not really LOL

I hear you on that one Frank !!!
I concur with Dan's statement "We have met the enemy and he is us."

 

Agree, loctite when wet is similar to lubed threads

 

I guess we'll have to agree to disagree. I'm sure it does provide some lubrication, but I don't see how a drop or two of loctite can be anywhere close to the lubrication you'd have by dipping the bolt in oil.

 

I think the oiled fastener would apply a little more clamping force than Loctite, the question would be is it enough to push you out of your torque range.