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Can someone explain how and why hot torquing injector can quiet them down.
If there were an noise issue.(ie. hammering), that would seem like a major failure of some type would be occurring. What's moving arround?
I have 50k on my last injector install and I think I'm hearing things along with way too much white smoke at startup.
Currently 399989 miles and getting ready for the 399999 photo.
Thanks, Bob
When you consider how much they move, vibrate, the heating cooling cycles involved then combine everything else that’s happening when the engine is running...things are going to vibrate loose. Are you’re glow plugs and GPR working? Below is the how to hot torque the injectors...
Can you tell us more about the injectors? Are they original, rebuilt or new AD's, or something else? How about the glow plugs/harness and GPR condition. Does the white smoke clear up after warming up? About how long does it take?
For a quick compression check at 399K, is blowby minimal if you unscrew your oil cap and set it on the opening upside down while idling?
Colorado350
Thanks for the instructions.
Rather than me worring about what exactly the hot torque solves, I'll just try it and see what happens.
I just can't imagine something causing an audible noise not leading to a major problem.
If I replace injector orings again, I will do it as part of the install.
Bob
Ever notice how the engine is louder when cold than when warm? Warm ICP is about 500 PSI, but when the block is cold, the Injector Control Pressure is about 700 PSI. Translated, that is 700 PSI of hammer force applied to the inner workings of the injector - so you'd better hold that sucker still to keep it from jumping. Wide open throttle test or passing a pokie? Now we're talking up to 2800 PSI of hammer force with a stock tune - do you remember what I said about holding that little jackhammer down and flat on the head face?
What does a jumping injector sound like? If the injector hold-down bolt is lackadaisical about its duties, the injector can jump up the tiniest amount against the "spring" holding it down - then slam back down on the face of the head when the injector cycle stops. The difference between loose and tight is akin to beating on the bench vise with a wrench vs. beating a wrench clamped in the vise with a dead blow. We're never going to be as quite as a modern diesel, but we can do better.
Cold-torquing doesn't compensate for what happens to the hold-down bolts when the engine is warm - hot-torquing does.
Can you tell us more about the injectors? Are they original, rebuilt or new AD's, or something else? How about the glow plugs/harness and GPR condition. Does the white smoke clear up after warming up? About how long does it take?
For a quick compression check at 399K, is blowby minimal if you unscrew your oil cap and set it on the opening upside down while idling?
Thanks for asking about the excessive white startup smoke. That could be a topic on is own. All new OEM injectors, plugs, gaskets & glowplug system.
The white smoke is gone after warm up & doesn't return till next morning. Much worse now that temps are below freezing.
Compression was about 375 psi on all cylinders.
Lower than I would of liked. Also more blow-by too.
No pressure on the cap thou. Oil consumption is about 2 qt/ 4000 miles, again, higher than I would like.
I may just live with the smoke and oil consumption.
The fuel mileage is phenomenal. 20 to 23 highway.
Can't have everything.....
Thanks, Bob
Ever notice how the engine is louder when cold than when warm? Warm ICP is about 500 PSI, but when the block is cold, the Injector Control Pressure is about 700 PSI. Translated, that is 700 PSI of hammer force applied to the inner workings of the injector - so you'd better hold that sucker still to keep it from jumping. Wide open throttle test or passing a pokie? Now we're talking up to 2800 PSI of hammer force with a stock tune - do you remember what I said about holding that little jackhammer down and flat on the head face?
What does a jumping injector sound like? If the injector hold-down bolt is lackadaisical about its duties, the injector can jump up the tiniest amount against the "spring" holding it down - then slam back down on the face of the head when the injector cycle stops. The difference between loose and tight is akin to beating on the bench vise with a wrench vs. beating a wrench clamped in the vise with a dead blow. We're never going to be as quite as a modern diesel, but we can do better.
Cold-torquing doesn't compensate for what happens to the hold-down bolts when the engine is warm - hot-torquing does.
Tugly, as always, you nailed it.
I was over thinking why there could be a sound change between say 70in/lbs. and 120in/lbs.
Hot torquing is best practice and makes sense.
My aircraft machinist brain still thinks in .0001 inches.(I made 1000's of the hydraulic pistons in aircraft pumps. The ball end was lapped .000050 round by hand)
I will sleep better tonight & enjoy your next plane ride.
Thanks, Bob
Thanks for asking about the excessive white startup smoke. That could be a topic on is own. All new OEM injectors, plugs, gaskets & glowplug system.
The white smoke is gone after warm up & doesn't return till next morning. Much worse now that temps are below freezing.
Compression was about 375 psi on all cylinders.
Lower than I would of liked. Also more blow-by too.
No pressure on the cap thou. Oil consumption is about 2 qt/ 4000 miles, again, higher than I would like.
I may just live with the smoke and oil consumption.
The fuel mileage is phenomenal. 20 to 23 highway.
Can't have everything.....
Thanks, Bob
What kind of oil do you have in it? I would be inclined to live with it as well until I had a better reason not to. I would maybe try a higher spec oil and see if it doesn't reduce consumption. I have not tried it yet personally (next time) but I have heard Redline 15W40 really cleans out the engine in short order as far as crud and deposits. Speaking of that you might also send an oil sample to Blackstone next time you change it if you have never done it.
This is good info. I'm planning on rebuilding my injectors in the near future. Does anyone have one that isn't working? I want to build my own holding dies to take the injectors apart.
This is good info. I'm planning on rebuilding my injectors in the near future. Does anyone have one that isn't working? I want to build my own holding dies to take the injectors apart.
What kind of oil do you have in it? I would be inclined to live with it as well until I had a better reason not to. I would maybe try a higher spec oil and see if it doesn't reduce consumption. I have not tried it yet personally (next time) but I have heard Redline 15W40 really cleans out the engine in short order as far as crud and deposits. Speaking of that you might also send an oil sample to Blackstone next time you change it if you have never done it.
Currently Shell T6. Oil has never turned black on dipstick/ 4k oil changes. Removed the motor at 350k and replaced all the outer problem areas. Injectors, glowplug, wires, fuel lines, oil pan, exhaust manifolds, up pipes, ect. Motor was spotless inside. 80% of its life on Delvac1. With 400k I decided not to have the oil tested. I drank (from 75 k to 250k) the Banks koolaid with their K&N filter. Always maintained it & checked the intake for dust & turbo fin wear, however it was a big mistake.
I attribute my low compression 375psi to that. But with 400k not too bad with fantastic MPG.(low 20's)
Many people claim different oil change consumption, but I would have to carefully take notes for sure.
Thanks, Bob
With that many miles, Injector Armature clearance might be too tight, that retards timing and makes more smoke on cold startups
You can shim injectors cheap from ebay or spend money on getting your set rebuilt
I oringed my injectors (black filter) and torqued cold
one got loose and made a lot of knocking in less than a few hundred miles
after hot torque, all is quiet now for past 2 years
50k on new OEM injectors. Current cold buzz test, all sound the same.
You said they were loose. How loose?
Torque can also be effected by oil on threads and other areas. So many little things at 120 in/lbs could mean a lot. Wish I could see the OEM assembly line technique.
Thanks, Bob.
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