2350 excessive smoke poor mileage and poor performance

[8pitcher]

(02-29-2024 )Rawze Wrote:  wow that thing looks really worn out and a lot of age on it.

Bought it in November of 22 with 2k miles supposedly 150k miles later here we are. Bearings and wheels are still in great shape. The rivets that hold the VGT on broke.

[8pitcher]

New turbo is in. VGT working properly monitored on test drive. But smoke is still pouring out of the stack at all times.

[Rawze]

(03-05-2024 )8pitcher Wrote:  New turbo is in. VGT working properly monitored on test drive. But smoke is still pouring out of the stack at all times.

maybe this helps...
http://rawze.com/forums/showthread.php?t...2#pid69262

[8pitcher]

(03-05-2024 )Rawze Wrote:  

(03-05-2024 )8pitcher Wrote:  New turbo is in. VGT working properly monitored on test drive. But smoke is still pouring out of the stack at all times.

maybe this helps...
http://rawze.com/forums/showthread.php?t...2#pid69262

250psi in 60 sec in leak down. Fuel pump is new last year. Only 130k miles on it. I don’t know what else to check. My thoughts are going towards the tune because it’s the only thing I don’t know enough about to check on. But I do want to check it to make sure. I’m so confused and running out of money fast.

[windowrattler]

What color smoke? Does it do it at idle where you can kill injectors to maybe isolate it? Do you have excessive crank case pressure/blow by? Did the turbo dump a bunch of oil into the CAC and you are getting residual oil burning out? Just some random thoughts for you.

[Rawze]

You said it was recent;y rebuilt.. all OEM internals and OEM head?... or after-garbage?.


I am suspecting some after-garbage was used for either the overhaul kit.. or the head?.. or a repaired head?... and not all brand new OEM only? - This assumption for the moment, considering you already said you tried used turbos and other used injectors and crap that was shoved it into an otherwise, should have been precision-built $40,000 commercial engine.

And who knows the quality (or lack thereof) of the overhaul process it went thru.

Every time someone tries to cheap-out on these engines.. it costs them waaay more than if they would have simply gone all in and done things 110% right. And if someone cannot afford to do things right then they should park the truck and go get a company job for a while if need be, so that they can save up towards getting things done correctly, re-group, go thru, and invest in the equipment properly. otherwise, it is nothing but a headache.

You claim it started smoking all the time. .. How and when does it smoke?. Black smoke?.. white smoke?... is there any blo-by coming from the oil tube when you idle it with the oil cap off it?.

Has the crank case filter been bypassed, drilled out, or a maintenance-free one installed?.. so that the engine crank-case can breathe without restriction?. Any crank case pressure buildup at all, and the turbo is going to bleed oil fumes and slobber into the intake.

Also... some engines, after a fresh overhaul, can take as many as 80k+ miles before they break in good and stop smoking a bit.

What boost is it making now that the used crap turbo was replaced with a proper OEM one?.

You claim is had poor performance.,. but then you say its over-boosting a bit. If it is getting above 34 psi in a hard pull.. then have the turbo programming adjusted down a tiny bit so that it only goes to 34 psi.. and this is NOT a sign of poor performance.. but a sign that it is making close to, if not full power.

You also claim it has terrible fuel mileage.. but you don't mention what that is?... what kind of freight you haul>?? what speeds do you run?.. and areas of the country you drive in?... etc? ..

What make/model truck?.. your tag says Pete 579?. if so then at least its an aero truck. - What is the rear end ratio?. and is it an auto-s$itter?.. or stick?.

... and are you driving by your boost gauge and driving it below 63 MPH? .. keeping it under 20-psi to help save fuel?.. and to lower operating costs ??? - I would say likely not if your claiming ita making 35+ all the time.

your doing a whole lot of complaining.. but none of your posts imply or seem to tell us that you are actually doing much of anything about it except throwing parts i=at it. The DRIVERS RIGHT FOOT IS 80% RESPONSIBLE FOR ALL FUEL MILEAGE AND PROFIT MARGINS IN TRUCKING!!!.

Getting the engine healthy and keeping it healthy by keeping it in tip-top shape is the next thing towards this, and you cannot do this if someone is shoving used and after-garbage parts at it, trying to save moneys .. so that it can cost them 2x-4x more in maintenance, more down time, and poor fuel mileage, because none of it works like it should, or was not done correctly.

[8pitcher]

(03-06-2024 )Rawze Wrote:  You said it was recent;y rebuilt.. all OEM internals and OEM head?... or after-garbage?.


I am suspecting some after-garbage was used for either the overhaul kit.. or the head?.. or a repaired head?... and not all brand new OEM only? - This assumption for the moment, considering you already said you tried used turbos and other used injectors and crap that was shoved it into an otherwise, should have been precision-built $40,000 commercial engine.

And who knows the quality (or lack thereof) of the overhaul process it went thru.

Every time someone tries to cheap-out on these engines.. it costs them waaay more than if they would have simply gone all in and done things 110% right. And if someone cannot afford to do things right then they should park the truck and go get a company job for a while if need be, so that they can save up towards getting things done correctly, re-group, go thru, and invest in the equipment properly. otherwise, it is nothing but a headache.

You claim it started smoking all the time. .. How and when does it smoke?. Black smoke?.. white smoke?... is there any blo-by coming from the oil tube when you idle it with the oil cap off it?.

Has the crank case filter been bypassed, drilled out, or a maintenance-free one installed?.. so that the engine crank-case can breathe without restriction?. Any crank case pressure buildup at all, and the turbo is going to bleed oil fumes and slobber into the intake.

Also... some engines, after a fresh overhaul, can take as many as 80k+ miles before they break in good and stop smoking a bit.

What boost is it making now that the used crap turbo was replaced with a proper OEM one?.

You claim is had poor performance.,. but then you say its over-boosting a bit. If it is getting above 34 psi in a hard pull.. then have the turbo programming adjusted down a tiny bit so that it only goes to 34 psi.. and this is NOT a sign of poor performance.. but a sign that it is making close to, if not full power.

You also claim it has terrible fuel mileage.. but you don't mention what that is?... what kind of freight you haul>?? what speeds do you run?.. and areas of the country you drive in?... etc? ..

What make/model truck?.. your tag says Pete 579?. if so then at least its an aero truck. - What is the rear end ratio?. and is it an auto-s$itter?.. or stick?.

... and are you driving by your boost gauge and driving it below 63 MPH? .. keeping it under 20-psi to help save fuel?.. and to lower operating costs ??? - I would say likely not if your claiming ita making 35+ all the time.

your doing a whole lot of complaining.. but none of your posts imply or seem to tell us that you are actually doing much of anything about it except throwing parts i=at it. The DRIVERS RIGHT FOOT IS 80% RESPONSIBLE FOR ALL FUEL MILEAGE AND PROFIT MARGINS IN TRUCKING!!!.

Getting the engine healthy and keeping it healthy by keeping it in tip-top shape is the next thing towards this, and you cannot do this if someone is shoving used and after-garbage parts at it, trying to save moneys .. so that it can cost them 2x-4x more in maintenance, more down time, and poor fuel mileage, because none of it works like it should, or was not done correctly.

Rebuilt October 2022 150k miles on the rebuild. It started to smoke all the time out of nowhere a couple weeks ago when at the same time the vgt started to clatter in the turbo. It is a Peterbilt 579 mileage hovers around 5 mpg I run 65mph on cruise. I don’t watch my boost gauge all the time but on hard pulls it above 35psi. I run flatbed freight. Truck has a 13 speed manual. Truck passed compression test through insite. Blow by through the oil fill is non existent. Nothing crazy has been done to the breather filter beside replacing it. No oil consumption on the motor. Smoke smells like fuel. I rebuilt the engine myself. Yes I used aftermarket parts but those parts have checked out good. No fuel in oil no loss of compression. Head was brand new when I rebuilt the motor. Cam was new as well. Injectors in it now are new. Turbo is new. Turbo actuator was new feb of last year. Fuel pump new Jan of last year.

Just went and drove the truck again. Still smokes on acceleration and constant throttle. No smoke without throttle input. Watched fuel rail pressure and the measured is leading the commanded by around 1000 psi.


This whole smoking deal started when the old turbo broke.

[8pitcher]

(03-05-2024 )windowrattler Wrote:  What color smoke? Does it do it at idle where you can kill injectors to maybe isolate it? Do you have excessive crank case pressure/blow by? Did the turbo dump a bunch of oil into the CAC and you are getting residual oil burning out? Just some random thoughts for you.

Smoke is blue grey to black on hard pulls. But consistently blue grey. No crankcase pressure. Old turbo didn’t spit any oil. VGT just came apart bearings and seals still all good. No smoke on idle

[8pitcher]

Found the problem once I started to tear the truck apart. The intake line on the cam completely fell apart. But wasn’t something I could visually see until after I removed the rockers. So now I’m waiting on parts gonna roll in new bearings, oil pump, cam, rollers on the rockers.