Replaced all 6 injectors, now leak test still fails

[race7820000]

Guess I should have read this thread lol my engine same year, same symptoms. Havent pulled the valve cover yet but it has 1,070,000 miles......head has never been off.
The engine brake has 3 levels, when u go from level 2 to 3 the tone changed a little but it doesn't feel any different.
Has vibrating at higher rpm
Idles ok, it's smoothish, but isnt quite right.
Seems like it loses power in higher gear.
Passed cutout and pressure test for injectors

[Husky05]

Here are the results, I'm pretty sore from barring the engine over last night.

Injector 1, 3, and 6 are the ones that failed leak test.

Checked the running clearance of the engine brake rocker with it at detent. The gap is few thousands greater than the numbers I have here, didn't want to spend a lot of time to find the exact gap just wanted to see if it was greater than the minimum limits and under the maximum limits.

The book says 0.025 to 0.110

Results are
1 0.051
2 0.063
3 0.063
4 0.051
5 0.071
6 0.070

I am now in process of replacing 1,3, and 6 injectors then put all back together and redo the leak test.

[Husky05]

Back to square one, with 3 new injectors in, still failed leak test everything is still the same.... I guess leaky head or something??

[Nilao]

Most likely a crack or bad injector cups. Rawze had a bad cup in cylinder 6 under a million miles.

[Husky05]

(10-31-2016 )Nilao Wrote:  Most likely a crack or bad injector cups. Rawze had a bad cup in cylinder 6 under a million miles.

Can that be replaced without needing to remove or replace the head?

[Nilao]

From my understanding, Cummins doesn't sell cups for the head. You have to replace it unfortunately. Rawze mentioned on his video some shops will try it. But at a million I'd just bite the bullet and Inframe it because most of the labor is done once the head is pulled and also just for peace of mind. At least do the bottom end and a reman head.

[Rawze]

At a million plus miles,.. let the injectors leak a bit if it is in the head, especially if nothing else is wrong. Just keep an eye on that detent clearance and treat it like the old lady that it is while planning on doing the whole thing up at once (in-frame) at the first signs of other troubles too.

[Rawze]

(10-31-2016 )Husky05 Wrote:  Here are the results, I'm pretty sore from barring the engine over last night.

Injector 1, 3, and 6 are the ones that failed leak test.

Checked the running clearance of the engine brake rocker with it at detent. The gap is few thousands greater than the numbers I have here, didn't want to spend a lot of time to find the exact gap just wanted to see if it was greater than the minimum limits and under the maximum limits.

The book says 0.025 to 0.110

Results are
1 0.051
2 0.063
3 0.063
4 0.051
5 0.071
6 0.070

I am now in process of replacing 1,3, and 6 injectors then put all back together and redo the leak test.

I made this video before I knew more about it but it does show how I usually check them. the one that was 0.025" ended up being 0.037" when we were done adjusting it if I remember correctly. The engine needed to be turned to the correct position for proper measurement.

[Ragindirt]

I know this is an old trend, but the beauty of this site is the knowledge and issues resolved.
Having the same issue as husky had.

My engine is a 871 2010 in a t800, still all factory cal. 706k miles, 25K hours. At 15k oil changes I use about a gallon of Rotella, no coolant loss (after fixing hose leak); about once a day coming to a hard jake assist stop, or jumping on a ramp she will roll a little white smoke.
Just replaced all sensor and did an erg tune, cans were cleaned; and there was no signs of any coolant leak (plus coolant pressure test tested ok).

March I ran the over head, plus put a jake rebuild kit in (springs, plungers). Did not know of this site so may have missed the detent, and wear specs on jake. "I mention this because truck slows to fast empty with trailer at 30K, and it has a pooping sound from exhaust with Jake off". Also has damn clatter under hood when you hit jake.

Vibration thru dash on a hard pull ( boost in the 30+, no pyro gauge ). Fuel mileage sucks(5.1) running I-80 from IA to KS, about fifty fifty on interstate and two lane. My average speed 65 to 70.

At idle she is a little rough, and inlet to air cleaner has a suck blow, really sudden but consistent, normal flat ground it is noticeable in cab, hard pull vibration increases so kind of nulls suck/blow sound. Number 6 at idle is low on temp with heat gun 371, all others up around 430 plus ( lost my sheet may be off here, shot two weeks ago).

Thinking I have a washed or burnt valve, along with a bad injector. Filled up both tanks yesterday to there 95% limit, 20 so miles into trip passenger gauge is all over the place (primary return on my truck), full- empty etc. More vapor in this tank lately then before; just a thought don't know if it has jack to due with Jack.

Looking like a new head, in frame, or treat her like an old lady until summer!?