Rough running

LMWatBullRun · **Posted:** Tue Aug 18, 2015 7:26 pm

So my DW calls me the other day and says-
"Dear, I am on my way to my appointment, and the Jeep seems to be making a lot more noise than normal."
"Oh, THAT is not good. What kind of noise?"
"Sort of a louder rattley noise..."
So, no smoke and OK oil levels and she gets the CRD home with no major problem.

Fast forward and I get home to start diagnosis.
There is a definite rapping noise. The rapping noise goes away when I unplug #1 injector, mostly; occasionally it seems to stumble
and run rougher. DW says, "Yes, that is what it was doing when I drove it!" Hmmm. "Oh, I meant to tell you that
it has been getting noisier off and on lately, not all the time, but it is getting worse and more frequent."
Hmmm. Unplugging any other one injector does NOT eliminate the noise, and the shaking and vibration gets worse.

"Was it worse going uphill?" "Yes, I think so." Hmmm. Priming pump is tight, more or less.

My first thought was that I had a problem of some sort strictly associated with #1 cylinder,
but that does not match the 'comes and goes' symptoms, not does it explain the stumbling.

Upon reflection at length, I suspect that I am starting to get air leaks in the fuel line.
Having read many threads about the frustrations of sorting this out I am going to simply
drop the tank and install a lift pump and see if that solves the problem. This is a mod
I was considering anyway, just not right now. So we shall see.

If that does not solve the issue, then my thoughts are-

1) have injectors checked

2) Check the rockers and valves

Anybody have other thoughts or suggestions?

LMW

Hexus · **Posted:** Tue Aug 18, 2015 8:05 pm

Just the tiniest bit of air in the fuel line can make some crazy noises in this thing. That being said, I saw all the needle bearings inside my rocker arms failed or nearly ate out of rockers that had never failed (YET) by the time I got it opened. I stand by my conviction that there was a bad run of rockers/lifters, and that they never accounted for the NA use of the EGR, and the acidity of the oil combined with the metallurgy of some of those rockers/lifters led to the disasters that we're seeing.

I would do what grandpa always said, "Fix the cheapest thing first!" Tighten and double check all of the fuel connections, change the fuel filter. It's beyond my reasoning why someone would unplug one of the fuel injectors on these vehicles while it's running....

Also, throw a cup of water into the injector recess while it's running, you can get blow-by as well as suction if the copper crush washers foul (known to happen) then the small gaskets on the fuel injectors will not hold pressure inward or outward. If you have any leakage in or out, you'll notice it really quickly.

Just thoughts, it's a LOT of work (as you well know if I recall) to get to those darn rockers/lifters.

LMWatBullRun · **Posted:** Thu Aug 20, 2015 7:30 am

Hexus wrote:

Just the tiniest bit of air in the fuel line can make some crazy noises in this thing.

So I understand!

That combined with the 'comes and goes' aspect was why I suspect air.

Hexus wrote:

That being said, I saw all the needle bearings inside my rocker arms failed or nearly ate out of rockers that had never failed (YET) by the time I got it opened. I stand by my conviction that there was a bad run of rockers/lifters, and that they never accounted for the NA use of the EGR, and the acidity of the oil combined with the metallurgy of some of those rockers/lifters led to the disasters that we're seeing.

I would do what grandpa always said, "Fix the cheapest thing first!" Tighten and double check all of the fuel connections, change the fuel filter. It's beyond my reasoning why someone would unplug one of the fuel injectors on these vehicles while it's running....

Also, throw a cup of water into the injector recess while it's running, you can get blow-by as well as suction if the copper crush washers foul (known to happen) then the small gaskets on the fuel injectors will not hold pressure inward or outward. If you have any leakage in or out, you'll notice it really quickly.

A GOOD suggestion, and I will do that this weekend. WRT injectors, I did not unplug while running, I stopped the motor and unplugged them.

Hexus wrote:

Just thoughts, it's a LOT of work (as you well know if I recall) to get to those darn rockers/lifters.

Yes, which was why I replaced them all when I did the studs. Right now I have only 16k on the new rockers.
I'd be really surprised if the rockers were bad, but odd things do happen. I will see what happens when I get the lift pump installed.
Thanks, Hexus!

LMW

funnyman06 · **Joined:** Sun Jul 06, 2014 7:46 pm **Posts:** 180

Does the sound change or go away when the AC clutch pulls in? I'm fighting an issue where my crank pulley wants to fall off. Starts sounding awful until you tighten it up. Also air in the fuel system makes the jeep sound horrendous, I added an intake and it got rid of all of my starting issues. Also check your tensioner and alternator pulley.

dirtmover · **Posted:** Thu Aug 20, 2015 11:07 am

Sounds like fuel delivery or air in fuel. While looking at the injectors it's also real easy to do a return flow comparison between them. I'd start by changing the fuel filter and then start to look for air leaks.

LMWatBullRun · **Posted:** Mon Sep 07, 2015 1:02 pm

Any ideas on draining the tank? I have ~20 gallons of diesel in it.....

Mountainman · **Posted:** Mon Sep 07, 2015 2:18 pm

If it was air, and you unplugged that injector. Wouldn't the air then get spit out of a different injector and cause the same surge or noise or whatever? Maybe it would take a bit for the air to navigate (fill part of the rail) until it gets to the next fuel line to cause the same trouble further down the line?

If unplugging "fixes the problem", even after it runs for a bit:
I'm thinking maybe injector running lean? Run a couple of bottles of cleaner on the next two tanks and see?

I say run that 20 gallons out with a bottle of injector cleaner

Or, just swap two injectors if you don't want to play wait and see

LMWatBullRun · **Posted:** Fri Sep 18, 2015 3:06 pm

OK. The rapping noise is NOT air in fuel. LIft pump functions well, keeps air from intruding, still have the rapping noise samesame.

Injectors are tight and no blowby.

No fuel leaks noted.

What I think I will do next is swap out another injector and see if that makes a difference. Other thoughts? Geordi? Sam?

flash7210 · **Posted:** Fri Sep 18, 2015 5:45 pm

I think you should do a injector return flow test.
If one of the injectors is injecting too much (and returning too little) it could cause the symptoms you are describing.

Hexus · **Posted:** Fri Sep 18, 2015 6:59 pm

LMW -

The air can stay trapped inside for quite a while.

Crack the fuel line near the bottom (Open it slightly with 11mm crow's foot socket[if memory serves] and run the lift pump, about 8 oz. of fuel through should purge any air. Start as far down-system as you can (front of the fuel rail where the line goes to injector #1).

Then close it up, prime it with the button, then see if it changes or the noise is still there.

****ALSO - DO NOT CHECK FOR FUEL LEAKS WITH HANDS, USE A PIECE OF CARDBOARD OR PAPER, FOR THE LOVE OF GOD!*****

rankom · **Posted:** Fri Sep 18, 2015 7:30 pm

looks like that injector , is about to fail, ( worn out) or maybe because i had this problem , and was smoking , rattling badly, i would test them.

thermorex · **Posted:** Fri Sep 18, 2015 11:44 pm

It can also be a bad electric connector that just started to act up. It won't throw a Cel till it stops running for a bit. When you notice this, try pushing the wires in the connector and wiggle them a bit. I had this Issue and I ended up first removing the dust cover of the electric plug, then, 2yrs later, replacing the whole plug.
The issue is like running in 3 cylinders, then back in 4, then again in 3 and so on.

LMWatBullRun · **Posted:** Fri Sep 25, 2015 2:46 pm

OK, finally had time to switch out injectors. Old injector VERY sooty and carboned up.
Replacement was one of Geordi's; looked good on the tip.
No problems installing; the lift pump made it easy to reprime and bleed the lines.
I like it!

Anyway, unfortunately, with the new injector, I get clouds of greyish white smoke, indicating incomplete ignition.
When I pull the plug on #1, no smoke. My guess is some sort of problem with either the rockers or the valves.
Ah well, maybe it is time to rebuild an engine or two and swap the rebuilt into this Jeep.

LMWatBullRun wrote:

OK. The rapping noise is NOT air in fuel. LIft pump functions well, keeps air from intruding, still have the rapping noise samesame.

Injectors are tight and no blowby.

No fuel leaks noted.

What I think I will do next is swap out another injector and see if that makes a difference. Other thoughts? Geordi? Sam?

geordi · **Posted:** Fri Sep 25, 2015 5:15 pm

It may not be incomplete combustion! First, don't forget that those injectors haven't been run in a *very* long time now, and the fuel that is in them is correspondingly old.

The engine rebuild that I just completed also stank and smoked white / grey clouds for probably about 15-20 minutes, as the engine was choking out all the detritus and cleaning fluids from not running in a long time. If your old injector failed out on you, it might have been drooling rather than spraying, and you now have added old rotten fuel to the collection of soot and carbon that had built up in the engine.

Is the noise still there? If not or it is mostly gone... Let it idle for a bit and see if it smooths out and loses the smoke. I'd bet it will. After only 16k miles, the chances of the rockers being at issue is so slim that I'm not even considering that.

racertracer · **Posted:** Fri Sep 25, 2015 6:49 pm

Possibly injector stiction.

Run a quality injector cleaner through the system, let it sit in the system ... especially the injectors over night. You may need run it a few times.

If you have never run a cleaner in the fuel system this may be your problem.

Read this.... http://www.fleetequipmentmag.com/sticti ... el-engine/

LMWatBullRun · **Posted:** Sat Sep 26, 2015 1:29 pm

geordi wrote:

It may not be incomplete combustion! First, don't forget that those injectors haven't been run in a *very* long time now, and the fuel that is in them is correspondingly old.

The engine rebuild that I just completed also stank and smoked white / grey clouds for probably about 15-20 minutes, as the engine was choking out all the detritus and cleaning fluids from not running in a long time. If your old injector failed out on you, it might have been drooling rather than spraying, and you now have added old rotten fuel to the collection of soot and carbon that had built up in the engine.

Is the noise still there? If not or it is mostly gone... Let it idle for a bit and see if it smooths out and loses the smoke. I'd bet it will. After only 16k miles, the chances of the rockers being at issue is so slim that I'm not even considering that.

the rapping noise is gone. I may put some lubramoly in and see.

rankom · **Posted:** Sat Sep 26, 2015 5:23 pm

after i replaced 2 bad injectors i only use stanadyne additive , on my jeep , and on my big truck pre emission detroit diesel engine , lucas sumer and howes winter time .

LMWatBullRun · **Posted:** Sat Sep 26, 2015 6:14 pm

geordi wrote:

It may not be incomplete combustion! First, don't forget that those injectors haven't been run in a *very* long time now, and the fuel that is in them is correspondingly old.

The engine rebuild that I just completed also stank and smoked white / grey clouds for probably about 15-20 minutes, as the engine was choking out all the detritus and cleaning fluids from not running in a long time. If your old injector failed out on you, it might have been drooling rather than spraying, and you now have added old rotten fuel to the collection of soot and carbon that had built up in the engine.

Is the noise still there? If not or it is mostly gone... Let it idle for a bit and see if it smooths out and loses the smoke. I'd bet it will. After only 16k miles, the chances of the rockers being at issue is so slim that I'm not even considering that.

Good bet.

Went out to the DW's CRD this afternoon with the intent of putting lubramoly in, and Vroom- fired right up, no smoke no problems. :SOMBRERO:

Warmed it up THOROUGHLY and went out and gave it an Italian tuneup running up a 10% grade flat out. Apart from a little bit of black smoke at the start, no problems! :-)r

Thanks for the tip, Drs. RacerTracer and Geordi!

geordi · **Posted:** Sun Sep 27, 2015 11:02 am

Good to hear it, glad it is back running!

If you find your local Diesel Fuel Injection Service shop, they should be the local Bosch certified service center. They should be able to fully test the removed injector and give you the spec sheet from the test. If it is out of specification, it can be rebuilt for FAR less than buying new, and the test should only be about $40-$60 or so.

Rough running

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