When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Yes very interesting. I do have to agree with them on the “relaxation” part. The last time I did injectors i torqued them to 120ft/lb. and the drove it for about 100 miles. Pulled the valve covers and guess what????? Not one injector re-torqued to 120. Most were around 100. And if I recall one was like 87? So I torqued them all again and no issues so far?
What are the chances that an old friend brings you an old Ford book as a gift and the answer to one of the most discussed topics is clearly spelled out in it...
Great find Jason, you will have to be sure to let your friend know he solved a great FTE mystery.
Once I get to my laptop I will be adding this to the Tech Folder for quick and easy reference.
For the sake of keeping the information readily accessible, I have pasted the image for the cover of the "7.3 DIT Power Stroke" engine data book below. The book cover was originally posted by SkySkiJason in this thread.
Oring melts allowing fuel into combustion chamber... I wonder if this is why I get 1 big black puff of smoke under hard acceleration sometimes... seems like it may be coming from 1 or 2 cylinders. May need to check orings... is this bulletin basically saying that you should hot torque the bolts?
Ive never lubed threads, but I don’t go out of my way to clean them - so some lube is in there!!?
I wonder if over torque can damage injector cups?
This is very interesting and I have often wondered this.
Originally Posted by SRBF150
Interesting, but I'm not buying the 50in/lb part. Best practice is going with up to 130 in/lb cold and then retorquing to 120 in/lb when hot.
I also had a little bit of this reservation, simply because the guys on here have "fixed" or made better on some Ford recommendations. That being said, I also know that there were 2 instances where I hot torqued injectors that were finger tight and the truck ran considerably better. Even my boss drove it and asked what I did to the truck. He thought I changed an overdue fuel filter LMAO.
Either way, this is good info and leaves us to make an informed decision. Personally, i will continue to do what I have been doing because it seems like a good maintenance item and it has produced good results. 140 in pounds? i dunno, but a re-torque is a good thing IMHO.
As I am reading this, I "just" finished buttoning up my engine last night after replacing the injector cups.
I opted for using Loctite as opposed to hot-torquing.
I completely cleaned and dried the threads on all of the injector hold-down bolts and their respective holes. I used Loctite 243 on them and torqued them to 130. I am thinking the still-liquid Loctite might have sufficed as thread lubricant. Time will tell.
Yes very interesting. I do have to agree with them on the “relaxation” part. The last time I did injectors i torqued them to 120ft/lb. and the drove it for about 100 miles. Pulled the valve covers and guess what????? Not one injector re-torqued to 120. Most were around 100. And if I recall one was like 87? So I torqued them all again and no issues so far?
Oring melts allowing fuel into combustion chamber... I wonder if this is why I get 1 big black puff of smoke under hard acceleration sometimes... seems like it may be coming from 1 or 2 cylinders. May need to check orings... is this bulletin basically saying that you should hot torque the bolts?
Not likely an o-ring problem.
Actually it is specifically saying no re-torque is needed unless below 50 in lbs - then pull injector and inspect for damage.
Yes very interesting. I do have to agree with them on the “relaxation” part. The last time I did injectors i torqued them to 120ft/lb. and the drove it for about 100 miles. Pulled the valve covers and guess what????? Not one injector re-torqued to 120. Most were around 100. And if I recall one was like 87? So I torqued them all again and no issues so far?
The big question is, what's going on with the "relaxation"? Is it the bolts loosening a little bit, or is it movement somewhere else in the system? If it the bolts moving after torquing, Loctite should fix that. If it's something else, well, I don't have an answer.
Based on my most recent experience in torquing injectors just a few days ago, it just seems like they are still moving downward as you're torquing them. It would seem that in a situation like this, the best approach would be to initially torque them to a much higher value, then back off and reset to the specified holding torque. Kind of like wheel bearings. This would ensure that the injector gets fully seated. Of course due to the low strength of the bolts and threads involved, this approach is not possible. So it does sound like hot-torquing would be the next best thing.
In my own case, if I wanted to a hot torque further on down the line, I may have muddied the waters. The cured Loctite I now have in the threads will certainly alter the torque values.
On the other hand I may be over thinking this. The whole reason I had to do the injector cups over again was because my crappy torque wrench was reading high. I drove around for 40k miles with injector bolts that were only torqued to around 80 in-lbs. The engine ran fine for most of that time, it wasn't until I noticed fuel in the coolant that I knew I had a problem. I was using the wrench on another engine, and decided to check the calibration, and when I saw that 120 displayed on the wrench translated to 80 actual, I put two and two together.
Many have said that doing a hot torque quiets the engine, that combined with the fear of loose injectors causing damage lead me to do mine. I was initially planning to record the engine before & after, then forgot. One of mine was scary loose, the others were just kinda loose. The #8 injector is somewhat new and it had the best torque, the others I think are original. I didn't notice any obvious change in sound or performance, but it only has 435k miles.
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
