Replaced all 6 injectors, now leak test still fails

[Husky05]

Hello all, I recently replaced all 6 injectors this summer, actually i did 2 in February or march, then did the rest 4 in the summer time. Engine is a 2006 ISX 450 CM870

Well now I'm having a weird rumble at upper rpms, more like big boy rumble when I'm under load from like 1300 rpm and up. I checked my valve clearance and it's all good, fresh oil, new fuel filters. Issue is still the same. So I decided to just run injector leak test. well front and rear bank shows bubbles in the water jug when i crank the engine over. I have not yet pin point which injector it is yet. So it's for sure 2 or more injectors.

I am wondering what could have caused 2 or more to fail so early, are the reman injectors well known to fail so early? I have at least about 80k miles on the first 2 replacement, and about 40-50k on the 4 replaced in the summer.

Could a leak in the fuel system other than the injectors cause air bubbles to come out in the water test?

[Hammerhead]

You didn't list your CPL or the injector part number, so I can't see if they're on the list, but I'd strongly suspect so...
Cummins has a Silent Recall for injectors. I'd like to say just a couple, but you should double check with the list in the thread link below. I don't suppose you have the packaging to check the date code without removal? I know I wouldn't.

Silent Injector Recall thread...
http://rawze.com/forums/showthread.php?tid=692

[Signature620]

Recall or not, all parts from Cummins have 12mnths warranty. Work out which one is leaking and take it back.

[Rawze]

(10-18-2016 )Husky05 Wrote:  Hello all, I recently replaced all 6 injectors this summer, actually i did 2 in February or march, then did the rest 4 in the summer time. Engine is a 2006 ISX 450 CM870

Well now I'm having a weird rumble at upper rpms, more like big boy rumble when I'm under load from like 1300 rpm and up. I checked my valve clearance and it's all good, fresh oil, new fuel filters. Issue is still the same. So I decided to just run injector leak test. well front and rear bank shows bubbles in the water jug when i crank the engine over. I have not yet pin point which injector it is yet. So it's for sure 2 or more injectors.

I am wondering what could have caused 2 or more to fail so early, are the reman injectors well known to fail so early? I have at least about 80k miles on the first 2 replacement, and about 40-50k on the 4 replaced in the summer.

Could a leak in the fuel system other than the injectors cause air bubbles to come out in the water test?

* What was the circumstances for replacing the injectors? -- and Was a leak test done at that time to help determine if they were bad?

* DID they NOT do a leak test AFTER they were replaced to ensure the new ones were not leaky? -- and to determine that it was not a crack in the head?

* Where were the injectors purchased? -- and WHAT kind of warranty are on them?

* WHAT is the date on the injectors (for recall purposes as stated above)?

===============

* Clogged exhaust/ restrictions (or failing DPF systems on the newer trucks) can cause leaky injectors.
* Incorrect programming (wrong cpl or wrong program for the size turbo you have) can cause it.

* Excess EGT's due to a myriad of reasons can cause leaky injectors

* Running around with the EGR valve unplugged all the time
(and not having MM-2 done properly on it ) on the CM870 can cause leaky injectors as well as a shortened turbocharger lifespan (because you always have excess EGT's).

===============
* What is your boost and pyro gauges reading/getting up to when you get it into a hard pull at maximum torque. (and if you got no gauges, your doing nothing but guessing at your problems any ways).


===============


Is it running rough at idle?

Did anyone bother to adjust the overhead before the test(s)?. Injectors out of adjustment can cause them to test leaky sometimes.

Is it a tiny bit of bubbles? or a LOT of bubbles?

Although it could be,... Just because your injectors are a bit leaky, does not mean that is your only problem.

Your rumble can be from many different sources, not just injectors. Please be more specific about "rumble.?" - what kind of rumble? vibration? ect.

Has anybody...

* Bothered to see how much wear is in the bottom end/rod bearings of the engine? -- miles? -- etc.?

* checked the static timing to see if it matched the timing cover? and also to see if it matched the serial number of the engine? -- CM870's have DIFFERENT TIMING CODES depending on serial number,... AND-- THE PROGRAM THAT IS IN THE ECM MUST MATCH THIS!!! -- YOU CANNOT JUST SLAP A DIFFERENT HP PROGRAM IN THEM WITHOUT VERIFYING THE TIMING WILL MATCH TOO!.

* Checked the crank and cam position sensors and the tone wheel on the crank?

* checked the timing and metering actuators?

* Checked the head for leaky/cracked valve? -- HOW OLD IS THE HEAD,.. and is it a re-man, if if so,.. where was it purchased and/or re-done at>>?

in other words,.... there are a LOT of unanswered questions,.. and without someone knowing them all,.. my truck E.S.P. is not working so good today lol.

[preacherboy24]

......or you can just run the truck over to Mr Hag or another guy like him and have him look it over.....

[Husky05]

Hello thanks for the responses.

No I did not document the injector information when I replaced them. I know the first 2 might be January or February 2016. The last 4 are March 2016 but one is 2007. When I saw one was 2007, the shop could not get another one in for at least another week. So I just put it in.

The reason of replacing the injectors, the first 2 had bubbles coming out, and pinpointed to 1 and 3. The rear bank had really small bubbles and I was having hard time pinpointing it. So I just did 1 and 3 at that time. Then over the summer, I ran the test again, and I could not pinpoint which one in the rear bank was leaky. So I just went ahead and replaced the rest of 4 just for peace of mind.

The original reason of suspicion was that at idle it was little shaky and it was always smooth since I bought the truck,so that lead me to do leak test.

No I did not run leak test after replacing them. I should have. The test I ran yesterday, shows one bubble per revolution for front Bank, the rear bank shows 2 bubbles per revolution. Bubble size is normal size I would say, kinda like the size of the tube diameter that came with the test kit.

I do have Pyro and boost gauge, I keep my egt 750° or less. I let it go to 800-850 once in a while on some hills. The boost I keep it 20 psi or less most of time on hills and passes. Sometimes I go to its max boost which is 25 psi once in a while.

Yes the egr is unplugged, with it plugged in, the egt gets over 750 so easy and at cruise it can be close to 750. I did not like that so I left it unplugged, it runs much cooler that way and cruise just shy of 500°.

It has stock Cal. No check engine light other than the egr as its unplugged.

The only thing done to motor when I bought it with 894k miles is the lower end was overhauled. The guy gave me the oil sample results when I bought it. I did oil sample again at 1 million, all normal. I just sent in a bottle to be sampled again and should be getting the results this week hopefully.

Head, turbo and pretty much everything engine related is original when I bought it. Turbo is in good condition, no play to the turbine wheel.

How do I check the timing? I know for gas engines I use timing light but diesel is different, and I would like to know how.

Tone wheel on crank??? Timing and metering actuators look good, the fuel cut off solenoid is brand new. How do I check the head for leaks? Is it possible to check without removing the head?

Truck now has 1,068,424 miles. Gets 6.4 mpg average, I get a lot of head winds in the Dakotas and eastern Montana. I run MN or IA to Pacific Northwest and back to MN.

She idles OK, just little skips, a normal person would think it's smooth. But to me it's different from when I bought it, it was so smooth no skips or shakes at all. The rumble is really hard to explain, when I give it throttle it's almost like there is leaky exhaust, kinda like popp, there is vibration felt on the floor and especially the pedals. I've had mechanics ride with Me and said it sounds fine, one said it sounds shaky, but doesn't think something is terribly wrong but should keep eye on things.

I don't lose coolant at all, I lose like 1 gallon of oil every 15k miles. Sometimes less than a gallon.

Where are the crank and cam sensors located? I can pull them and check their conditions.

[hhow55]

Go to quickserve.cummins.com
Enter your esn and learn where things are located in your motor.

[Rawze]

If the head is that old, it is most likely time for a new head. What is the clearances between the detent and the contact point of the engine break rockers after they are set/adjusted to their correct height?. If it is less than 0.031" or so, the head/ exhaust valve seats are worn out. Most ISX heads wear out by the time they get to about 750k or so.

[Waterloo]

First thing I thought, head is shot... Clearances. Just got my new dial gauge torque wrench to do overhead... ;-) Thanks Rawze!