N14 Fuel/Smoke issue

Jimmyhoffa816

Active Member
I've got a 1998 Freightliner classic with a 2000 N14 CelectPlus 525. From the beginning I got the engine from shop that said it only had 400k on over haul. So I bought engine, from Start it had a miss, had the ECM rebuilt, new fuel lines, bypassed the ECM cooling plate, replaced fuel shut off valves on top of transmission with non valve T's, finally found out it was number 6 injector. So I replaced 5&6 together, ran fine but was smoking blue white at idle, and using 1 gal of oil every 2k(it does have leaks) and had some pretty good blow by, oil painting 18-20 at 700rpms and 32-35 at 1200 rpms and up, alright so I tore all three heads off, cylinders and Pistons look like they have less than 200k. Took heads to machine shop, they said valve seats were shot on exhaust side and not much better on intake, and injector cups shot. So did complete valve job and new injector cups. Got heads back block is in decent shape. Smoothed and reinstalled heads new gaskets all the way up. Overhead ran. New fresh coolant. Oil. All filters new. Fired up runs good, went from kck to Seattle and back to smoking at idle. Exhaust Smells of fuel. Oil painting unchanged. No fluids mixing. Blow by is not nearly as bad. Used 1.25 gal of oil for 3900 miles. Swapping gears only gives a little black. But no smoke while cruising. Plenty of power, more than it had before head job. But when idle white/blue. Ok so I'm thinking I've got an injector issue, over fueling. Older guy that taught me alot about the N14 used to use a heat gun on exhaust ports to check for over fueling injectors when the truck wasn't missing for interior cut out yet (unplugging each injector) so I did that let idle for 30 mins at 1000rpms and got following results:
#1-187
#2-222
#3-230
#4-198
#5-197
#6-175
So after this I'm thinking my issue might lie in #2&3 since they are alot hotter than the others, number 5&6 are new.(I know it's better to replace 6 at a time but didn't/don't have funds) so I'm thinking of replacing 2&3 with new injectors, then I will replace last two next pay check. Then all six will be new, MPG has been around the same from day one till now 4.7-5.3, I have another classic with same engine getting 5.5-6.5, so I know it can do better. Any thoughts on if I'm on the right track here would be greatly appreciated
 
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Hammer166

Instigateur №166™
Sounds like you've eliminated most everything else. Do you have the equipment to do the injector cutout test? That would show the overfueling, wouldn't it?

What it sounds like, based on the other stuff you've found, is that whoever rebuilt it did the cheapest job the could. Probably just jerked the heads and never touched them until it was time to go back on the block. Hopefully they at least changed the front and rear crank seals while they were in there! I'd pop the exhaust and intake off the turbo and have a peek, if I were you, as it was likely untouched as well. Oil consumption is still a touch too high to my mind, but that could be your leaks causing that.
 

Jimmyhoffa816

Active Member
I don't have the computer stuff for injector cut out tests.

When I had the heads off the turbo was off both sides were dry no oil, no slop in bearings in any direction.

The guy at machine shop said same thing about the rebuild said the heads looked original never touched from the wear and tear they had.

The rear seal leaks a little bit so doubt they did it. Oil pan gasket need replacing and can followers leak a little. And I got a rocker box leaking (guessing bad gasket out of the box) so gotta tear that back down sometime.

I did forget to mention it idles a little rough below 900 rpms. But it's smooth as silk over. It didn't miss just sounds rough.

Also after idling for awhile you can hit the throttle real quick and she'll let out big clouds of white smoke. Also when it starts for the first time after sitting all night she'll let out quite a bit of white smoke
 
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Hammer166

Instigateur №166™
I don't have the computer stuff for injector cut out tests.

When I had the heads off the turbo was off both sides were dry no oil, no slop in bearings in any direction.

The guy at machine shop said same thing about the rebuild said the heads looked original never touched from the wear and tear they had.

The rear seal leaks a little bit so doubt they did it. Oil pan gasket need replacing and can followers leak a little. And I got a rocker box leaking (guessing bad gasket out of the box) so gotta tear that back down sometime.

I did forget to mention it idles a little rough below 900 rpms. But it's smooth as silk over. It didn't miss just sounds rough.

Also after idling for awhile you can hit the throttle real quick and she'll let out big clouds of white smoke. Also when it starts for the first time after sitting all night she'll let out quite a bit of white smoke
Sure sounds like an injector tip (or two) not sealing up, doesn't it?
 

Jimmyhoffa816

Active Member
If it wasn't seated wouldn't you have fuel going into the oil? And with the hold down clamp wouldn't something have to break loose for injector to unseat? I've never had these issues before so this is all new to me.

I mean it's symptoms could justify that, that's why I was thinking it was an injector issue the mechanical side not functioning properly. Cummins told me it won't throw a code unless the issue is electrical, they said the computer won't register issues on mechanical side so won't throw any codes, so the ECM can't help me lol.

And when I seen cylinders 2&3 running quite a bit hotter then the rest I kinda thought those two might be my problem.

I'm going to tear down and check everything this week now that I'm back from my round
 

Hammer166

Instigateur №166™
If it wasn't seated wouldn't you have fuel going into the oil? And with the hold down clamp wouldn't something have to break loose for injector to unseat? I've never had these issues before so this is all new to me.

I mean it's symptoms could justify that, that's why I was thinking it was an injector issue the mechanical side not functioning properly. Cummins told me it won't throw a code unless the issue is electrical, they said the computer won't register issues on mechanical side so won't throw any codes, so the ECM can't help me lol.

And when I seen cylinders 2&3 running quite a bit hotter then the rest I kinda thought those two might be my problem.

I'm going to tear down and check everything this week now that I'm back from my round
I was thinking more of the injector not completely sealing internally. I'm not sure how bad a drip it takes to show up in the oil. I suppose it's possible to get those symptoms if the nozzle spray pattern is bad enough you're getting streams instead of droplets, too. But yeah, something mechanically wrong with the injector itself.
 

Jimmyhoffa816

Active Member
That's what I'm thinking with those hot temps and poor MPG and smoke. And those 4 injectors were pretty carboned on tips, so I'm assuming these last 4 injectors may be original also like the heads were. I guess I'll replace those two this week and hope for the best. I'm running out of things to replace .

I've also noticed that the idle and smoke calm down a little when I add a concentrated additive to my fuel (like howes mean cleaner) which used to help number 6 injector when it would stutter before I know it was that injector, if I added that stuff it wouldn't stutter till next full up.
 

r3gulator3

IMA KEEP IT REDNECK
Supporter
Replace all injectors that haven't been replaced and do a liner kit on #6. That's what I would do. Just my opinion Your mileage may vary.
 

Jimmyhoffa816

Active Member
Number 6 liner looked like new like the rest of them? No liners had any marks or blemishes.
Just curious on why you'd replace it?

And due to money I'm going to have to replace two injectors this week (the two running alot hotter than rest) and two next pay, but yes I'm going to just replace them so I know they are good.
 

r3gulator3

IMA KEEP IT REDNECK
Supporter
We're the hash marks still visible? It's the weakest cylinder and was the one where you had the most severe injector problem before. My guess is that cylinder is either out of round slightly from over fueling or there is some minor wash out creating a weak cylinder. Rest of your injectors are too far apart. 5 and 4 showing best results. If you are doing them one or two at a time start with 2 & 3. But I would get them all replaced. #6 could have not gotten a good compression seat but with you burning that much oil I would go with it passing the rings more likely.
 

r3gulator3

IMA KEEP IT REDNECK
Supporter
You could always do a cylinder leak down test on it and roll each piston from bottom to top and see if you have any dramatic cylinder leakage that would help to identify any where that oil could be passing and prove which liners are in good/bad condition.
 

Jimmyhoffa816

Active Member
Is that where you put the dummy injector tool in and lock it down like you'd do an injector then put psi gauge on it and turn over engine till that hole gets up to spec psi inside then let set to see if it looses any psi?

Before I did the head job I did the heat test with the new injectors in 5&6 and these are those results(I just found the copy I took down)

Engine at operating temp idled to 1000 rpms

1-212
2-234
3-240
4-222
5-213
6-201
 
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r3gulator3

IMA KEEP IT REDNECK
Supporter
Yeah usually there is a second gauge on there that has percentage on it. And the air constantly flows. No cylinder is 100% so your looking for 75% or better on that gauge. Shop air is usually regulated down to 60-70 psi for this test. You also normally do this with a cold engine. If you have a cylider that holds 75% or better pressure cold it's doing pretty good.

And more that 25+/- torque deviation is considered bad by Cummins. So 2&3 are your worst injectors in this set of results also. Losing that much torque on #6 after doing heads there is a problem there but having 2&3 be that bad it could be throwing off the results. Having a second set of numbers to work with I'd now say replace 2&3, do a cylinder leakage test and ensure everything is holding. Then retest. It concerns me that you burned a gallon and a half of oil in less than 5000 miles. That is NO GOOD. It's either going out the stack via bad turbo, bad valve (guides/seats or crack in head that was not noticed) bad gasket( head gasket oil passage to fire ring cracked or not properly seated. Either that or it's going out the blow by tube.
 

Jimmyhoffa816

Active Member
Oh ok, yeah I was thinking of getting the things needed to do that test before I did the heads and head gaskets, the heads were completely rebuilt anything that can be replaced was and after that he said they passed all tests.

Before doing the heads the blow by would have a small puddle under it the next morning after sitting all night (little more if I idled) now the blow by might have a drop or two on ground but nothing even close to what it was, along with not coating my tanks as bad, the only thing I know to check on turbo is if there is oil in either side or top tube going to air to air, which I will check again tomorrow after it being back on the road after the engine work but when I put the heads on it was all dry up to that point(checked few times since got engine in the truck because I thought of that first with oil usage).

Only oil leaks it has currently is rear main seal has a tiny spot under it each night, front cam follower is leaking a little small spot under it, and few spots around pan where the guy helping out engine in didn't torque pan bolts and by the time I noticed after first trip I believe oil ate up the gasket so it needs changed. And my number two rocker box has a leak after getting it all back together I'm guessing just a bad gasket because it was torqued to spec and double checked like the heads, so gotta change it out.

I guess I will start by replacing 2&3 this week and either see about getting needed supplies for leak test or see what Cummins would charge to do it.

Would timing effect any of this? I've manually timed a couple of N14's using the Injector timing kit that measures injector travel and piston travel then shim the cam followers accordingly. But I cant imagine 2&3 being the only ones out since they are on different sections and the ones next to them(1&4) seem to be fine heat wise. It doesn't knock or make any unusual noises, sounds like every other N14 I've owned just this one is giving me issues I have never encountered before.
 

r3gulator3

IMA KEEP IT REDNECK
Supporter
Oh ok, yeah I was thinking of getting the things needed to do that test before I did the heads and head gaskets, the heads were completely rebuilt anything that can be replaced was and after that he said they passed all tests.

Before doing the heads the blow by would have a small puddle under it the next morning after sitting all night (little more if I idled) now the blow by might have a drop or two on ground but nothing even close to what it was, along with not coating my tanks as bad, the only thing I know to check on turbo is if there is oil in either side or top tube going to air to air, which I will check again tomorrow after it being back on the road after the engine work but when I put the heads on it was all dry up to that point(checked few times since got engine in the truck because I thought of that first with oil usage).

Only oil leaks it has currently is rear main seal has a tiny spot under it each night, front cam follower is leaking a little small spot under it, and few spots around pan where the guy helping out engine in didn't torque pan bolts and by the time I noticed after first trip I believe oil ate up the gasket so it needs changed. And my number two rocker box has a leak after getting it all back together I'm guessing just a bad gasket because it was torqued to spec and double checked like the heads, so gotta change it out.

I guess I will start by replacing 2&3 this week and either see about getting needed supplies for leak test or see what Cummins would charge to do it.

Would timing effect any of this? I've manually timed a couple of N14's using the Injector timing kit that measures injector travel and piston travel then shim the cam followers accordingly. But I cant imagine 2&3 being the only ones out since they are on different sections and the ones next to them(1&4) seem to be fine heat wise. It doesn't knock or make any unusual noises, sounds like every other N14 I've owned just this one is giving me issues I have never encountered before.
With the problems your having I wouldn't suspect a timing issue. I believe this to be injecotr issues compiled with oil leaks and some oil consumption. But my eyes aren't on the engine so I'm just giving my two cents based on the information you are giving me. But it sounds like you have a pretty solid plan of attack at this point.
 

Jimmyhoffa816

Active Member
Well I got #2&3 injectors replaced Thursdat, had to relay a load so took a 120 mile round trip (60 loaded at 76k, 60 empty 35k) ran good and smooth, didn't notice any smoke when it was idling and only got black smoke while going thru gears. As soon as I got back did a heat test. 1st test is immediately after stopping 2nd is about 10-15 min cool down with engine fan. Both tests 1000 rpm idle.
1-251
2-300
3-304
4-299
5-293
6-254
2nd
1-227
2-259
3-261
4-255
5-247
6-225
Engine temp was 170-180 for both tests, oil temp was about 150.
Injectors 5&6 replaced 8/31/17
2&3 11/2/17 all jumpers are new.

Also Monday I was under my truck looking at few things when I noticed my 4 back oil pan bolts where just hanging there. So I torqued them to spec (30ft lbs) and went around the pan where several more had backed out torqued them to spec (50ft lbs) then checked the draw tube on side of pan it was fine tight so torqued to spec (30ft lbs) so after this I think my rear oil leak may of been the pan since it wasn't even touching block oil just slopping out, along with rest of pan. And my oil psi fluctuations may have been due to draw tube bring lose and sucking air. So we will see now that I'm headed to Oregon if anything changes.
 

Jimmyhoffa816

Active Member
Made it to Oregon, running good, have new oil leak around oil pump area so have to figure that out. Still smoking at extended idle at 25 degrees at 1000 rpms over night. And also now notice the tops of my 6" straight pipes are turning blue right below the coal black soot around the edges of pipes. Engine never really gets hot, engine temp gauge runs right in the middle of 150 and 200. It's got new 180 thermos along with fresh anti freeze, it's not using any water, just oil still(which I believe is now more so because of the leak I got to try and find around the oil pump area). I don't have a pyro hooked up because whoever owned truck before Jerry rigged a turbo elbow and removed the stinger so in the process of getting new elbow and stinger. Her power is definitely coming back up with injectors getting broke in, fuel Mileage isn't the best 4.8-5.3(with two nights of idling 12 degrees and 20 degrees) I think fuel mileage has alot to do with the fact I've got a stand up style Peterbilt type sleeper(Freightliners version) and half of the reefer I pull is exposed, so I figure a whale tail or something would definitely help that out,

That's the current status of the old beast, still some smoke during extended idle, (it is idling and starting smoother) no smoke going down road except between gears (and even that's not much anymore) and tops turning blue under black soot.
 

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Jimmyhoffa816

Active Member
Update* got last two injectors in, all injectors are new now, pulled the exhaust side of turbo off had some oil behind the fan fins, so I removed turbo and installed a spare one I had, it’s used and got quite a few miles on it, and has sat for about a year, but when removed the worked fine with no leaks, it’s on the truck now. I used the truck locally a few days just moving trailers etc. and she still smoking at idle, but idle oil psi is a bit higher with this turbo, and this turbo is quite noticeably louder as in you can hear it whistling very clearly from 700rpms idle -1800rpms under power, Once you take off and it blows some smoke at take off it doesn’t smoke down road or under power that I can see. Smoke is white/grey at idle and take off.

I just pulled it apart this morning and there is no oil in exhaust side, no oil in intake side or air charger tube.

I’m going to run down today and get an oil analysis kit and have one sent it one it to see if something internally is going on.

Idk if it’s smoking due to turbo breaking back in or if I got an internal issue. After the oil analysis I should know more hopefully.
 

Jimmyhoffa816

Active Member
Still smoking at idle. Smells like oil. Smoke is blue/white. No using water. Switched it to rotella t5 synthetic blend 15-40. Using a gallon every 1800-2400 miles depending if I idle alot. It does leak around cam followers, oil pan gasket. So it's not burning all of it atleast. After extended idle 8-14hrs at 850-900 rpms the splits in exhaust manifold are soaked at bottom drooling. Turbo exhaust wet drooling. I'm assuming it's oil. I swapped turbos with another I had. Smoke calmed down a tad but not alot. Oil psi 20-22 at idle(700) 25-27 at idle (900) 32-36 running down the road (1300-1500rpm) all levels at full operating temp. Water 170-180(never gets hot barely use engine fan) oil temps 150-170. Turbo gauge doesn't always work but when pulling hills it does register 28-32lbs of boost psi. Pyro isn't working right now but I know she's getting warm since the tops of my 6" straights are turning blue. Truck has power on the road. Mpg is staying around 5-5.6 (classic xl with Peterbilt 379 style slept on it, pulling reefer with nothing on sleeper to deflect air over trailer) set the over head after installing all injectors. Did the injectors by tightening till it stopped then backed out and redid that too get fuel out, then bottomed out again and backed off two flats. Intake .14 exhaust .27 Jake's .23. I guess my only option is to take too Cummins and have them run cylinder test at this point.

Ran another temp test tonight these are results

1-210
2-227
3-229
4-212
5-210
6-208

900 RPM full temp idling 1 hr
 
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