Injector hot torquing.
 

Hey guys. There has been debate, small and civil, but still debate about whether or not hot torquing our injectors is necessary. Well a good while back I did some work on my truck. Radiator water pump rebuilt my oil cooler and injector orings. I wrapped it all up cold, torqued my injectors cold and called it good. 1000 or so miles later my 7.3 was back to being loud with knocking and clattering and ticking so I decided I would go back in a re torque my injectors, but do them hot. Doing so I was able to get a complete round on the hold down bolts. And of course it's much quieter, no knocking or ticking, just the normal 7.3 sounds. I just wanted to throw this out there. It is a fact that injectors should be torqued with the engine hot rather than cold. And yes I'm sure they were torqued properly the first time.. only on a cold engine. Thanks for reading.

^^ yes it's true I also learned that the hard way when I first starting messing with the 7.3 engines at work along time ago, I also notice that if you clean the bolt and threads with brake cleaner and blow dry them the torque on the bolts almost always stay with in spec when hot torqued just an FYI.

Great info! I tried to rep from my phone, but no dice.

Tee shirts! Get your "I have a loose screw" tee shirts here! No need to push, I have plenty of 'em.

I figured as long as there's a crowd, I'd sell off some of my excess inventory. I had a hard, miserable lesson sorting this one out - I couldn't find anybody at the time who knew this issue before me.

I hot-torqued mine when I installed them. I was glad I did. They all took a little more to get back to spec, and a few of them took most of a full turn. I would definitely say it's necessary.

Did anyone use loctite on them in addition to hot torque? I think Rich was also sponsoring this idea, but I am not 100% on it.

Seems like there is a cult or a sub-culture brewing here... Perhaps I can join when I swap my OEM injectors out for 160/80's.

I used loctite 243 on the upper bolts only, after blowing the hole out with BPC and compressed air.

I cleaned the holes with brake kleen and compressed air but I didn't use loctite.

I used 243 on the upper hold down bolts after thoroughly cleaning the bolts and holes when I changed injectors in Dec'16 because that is where my loose hold down bolt problem was.

I then hot torqued the lowers to something north of factory spec which as we all know is 120 in/lbs. I don't want to start the old torque spec war of words here again; however, I watched/assisted a very experienced diesel tech install eight injectors. He allowed me to check the torque values post HIS install. I was a little surprised by the value that I found.

His thought is that the FORD/International torque spec is not high enough to properly compress/seat/seal the copper washer between the injector and cup and that this is what leads to loose/loud injectors.

I saw this engine crank and run immediately after the injector install and it was considerably quieter than most 7.3's at that point. I then saw it again after about 5k miles and it was still a very quiet engine. I now use that spec.

When I was at BTS in Feb'17, Brian stated the same exact thing totally unprompted by me while we were watching one of his techs do an injector install.

An added bonus is that the truck in my sig is quieter than it has ever been.

so what did you torque them to?

I torqued mine to 133 in/lbs. 130 using a 3in extension.

im about to do my orings and was interested in this torque spec. Would like to do this, but is there any negative aspects? Any nightmare stories of bolts breaking or anything?

Not sure. If I remember correctly 120 in/lbs is the proper specs. I went 130 in/lbs..please wait for someone who truly knows lol. I had read on here about the 130 in/lbs. But I don't know who sponsored the info.

I can't imagine. It's only 12 ft lbs, which is pretty light considering. I hot torqued my last OBS injector job at 130. It's was a pretty smooth and quiet truck after that.