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Topic: Lots of White Smoke (Read 7819 times) previous topic - next topic

Lots of White Smoke

The engine has been emitting a small bit of white smoke since we've owned it.  I thought it was due to a bad turbo because the engine was rebuilt in 2017 and the invoice from the repair mentioned a damaged turbo. We were planning on replacing the turbo when the time came.  A couple of weeks ago we had to have our exhaust manifold gaskets replaced because one blew out sometime during our trip (the same one is leaking again).  The mechanic reiterated what the invoice said and the the turbo needed replaced.  We got to WV, I replaced the turbo and the smoke was still there.  On the test drive to check the turbo the engine ran great but while we were heading down the mountain on our way back the engine blew a huge cloud of white smoke out the exhaust.  It only happened once during descent and it was during deceleration.  After that it didn't seem to smoke at all the rest of the test drive and it was still running great. 

When I started it again two days ago the engine began emitting large amounts of white smoke.  It smokes at idle and it smokes worse when it's revved.  The engine seems to idle smoothly but It smokes the same after the engine is warmed up as well.  The exhaust does not really smell sweet nor does it smell strongly of diesel and it's not really acrid.  It just smells like old diesel engine exhaust to me.  There doesn't appear to be any water in the oil or oil in the antifreeze.  I don't believe that it is water vapor and am sure it is smoke.  The engine oil level does not appear to be dropping over time.  I haven't found a glass fuel bowl anywhere to see if there is air in fuel. 

I have called a couple of Cummins shops and they said it sounds like a fuel system problem.  They named a few things it could  be but none of them were interested in looking at it.  There are no other shops in the area and I'm not sure if it's a good idea to try and drive the coach a long distance with the way it is smoking. 

I'm in uncharted waters here. We have the operation and maintenance manual but it's not too specific.  Ordering a service manual is first on the list.  I'm not a diesel mechanic but would like to try and diagnose the problem.  If anyone has any suggestions I would be interested to hear them. 

Thank you

Re: Lots of White Smoke

Reply #1 –
My 8.3 smokes when cold on startup.

Causes from the web:

Faulty or damaged injectors
Incorrect injection timing (could be a worn timing gear or damaged crankshaft keyway).

Low cylinder compression
(eg caused by leaking or broken valves, piston ring sticking, cylinder and/or ring wear, or cylinder glaze)...

Raw diesel coming through the exhaust completely intact and unburned.

Water entering combustion spaces.
Faulty head gaskets and cracked cylinder heads or blocks are a common cause of water entry, and are often to blame. Unfortunately, expensive mechanical repair is the only proper solution here.

Re: Lots of White Smoke

Reply #2 –
It could be the oil seal in the new turbo is faulty. Even though you can't see any oil loss on the dip stick it don't take much oil to make a lot of smoke. This can look like white smoke even though it is oil.
 
With the 2nd exhaust manifold gasket failure you need to check the manifold for warpage and correct that before installing another gasket. If the manifold is warped have it surfaced and you will be better off than a new manifold in most cases due to heat warpage of the new manifold.  The old one has went through untold number of heat cycles so it has most likely done all the warping it is going to do.

Mike

Re: Lots of White Smoke

Reply #3 –
If it's a bad turbo, you will 'eat oil for lunch' and smoke white/grey all the time; more when it's colder outside when climbing. We blew one, replaced it and it STILL SMOKED!  Pulled the whole top end apart, had everything checked out and found nothing. Pulled the turbo and found the seals were shot on the new one! The REP replaced it n/c, but I ate the labor. We could only figure the 'new' one had sat on the shelf too long and the seals had dried out.  :headwall:

Re: Lots of White Smoke

Reply #4 –

Quote from: The Soft Boulders –

I'm in uncharted waters here. We have the operation and maintenance manual but it's not too specific.  Ordering a service manual is first on the list.  I'm not a diesel mechanic but would like to try and diagnose the problem.  If anyone has any suggestions I would be interested to hear them. 

Thank you

Let's start with a basic assumption here because white smoke is usually unburned fuel.  If it was anti-freeze from a bad head gasket you can smell the antifreeze and if you rub your hands in the exhaust you'll feel the anti freeze.  BTDT.

Does your maintenance manual outline the ignition timing procedure?  If you have a mechanical engine, you time the injector pump using timing pin(s).  One for top dead center on the engine and one for the pump. 

Do the simple things first.

Art Joly

Re: Lots of White Smoke

Reply #5 –
I think the key here may be the engine rebuild in 2017. White smoke is normal during startup, especially in cold weather. White smoke during normal driving is not. The white smoke from coolant at first looks the same as startup smoke but quickly dissipates and since your coolant level is not going down, you can rule that out. Does your engine start quickly? Did they check or replace the fuel supply hose? Air in the system can cause intermittent amounts of diesel injected and can result in white smoke. A lift pump that was not replaced at the overhaul could be failing causing low pressure and insufficient fuel in the Bosch P pump. Also could be the cause of the white smoke. This is one of the reasons I installed a pressure gauge on the secondary filter discharge/outlet as it checks on filter condition, lift pump, air leaks, etc.

White smoke from other than a fuel supply problem usually occurs after combustion and since you have a four stroke diesel, there is a possibility that an oil ring might have been installed upside down or damaged and some oil is going out on the exhaust stroke. Another possible reason could be worn/damaged exhaust guides/seals. But the first think I would look at is the turbo seal after you are sure you don't have air in the fuel system. Even a small amount will produce a white smoke with a possible blueish cast to it. It usually has an odor to it and if you have someone follow you, they can do a smell test.

Injectors with a bad pattern usually show up as poor starting. Once the engine is warm, a torn injector pattern will probably only show up as increased smog emissions.

Injector timing could be off. Easy to check.

What kind of overhaul did the shop do? New set of pistons/liners. What kind of head work was done? Cummins shop?

Phone calls to Cummins and their answer was probably correct with the fuel system diagnosis. I would start there and go to engine mechanicals after that. Any diesel issues are probably due 80% to the fuel system. Since your engine is using no oil or coolant, I would lean to Cummins answers first.

Pierce


Re: Lots of White Smoke

Reply #6 –
Faulty injector.
  Run a balance test. Let it skip long enough for the smoke to diminish.

Re: Lots of White Smoke

Reply #7 –
I have removed the intake and exhaust pipes on the turbo and there is no oil or residue.  There is white smoke coming from the leaking manifold gasket so I don't think it's the turbo.  We ran the generator under load to see it would smoke as well maybe indicating water in the fuel.  The generator wasn't smoking but dies after about 10 minutes for some reason.  I'm not sure how long smoke would linger vs steam but it doesn't seem to hang around in the air like smoke from a fire. 

The engine starts and idles fine.  I have ordered both the shop service manual and the related troubleshooting manual to help me visualize what everyone is talking about.

Re: Lots of White Smoke

Reply #8 –
Unless you need a new fuel filter, your generator is dying because it has air in the feed line. Our U300 is the same year and the supply line from the tank had millions of microscopic cracks that were letting air in. Tough to see without a magnifying glass. Super easy to check by substituting a three foot hose from a gallon container of diesel and then running the generator with at least one roof air on. If it keeps running, you have a bad supply hose.

Easy to change. Buy a 25 foot roll of good hose as it's much cheaper that way. Don't even have to pull the generator out. Use a long rod like a straight brake line to feed it though the bulkhead hole into the fuel tank compartment. Don't connect it to the old hose as Foretravel didn't install the OEM hose in a straight line so may get hung up if you do it that way. And don't view the Foretravel on YouTube as its wrong.

Your engine feed line may have the same problem and is allowing air into the system.

Pierce

Re: Lots of White Smoke

Reply #9 –
Quote from: mike leary –
If it's a bad turbo, you will 'eat oil for lunch' and smoke white/grey all the time; more when it's colder outside when climbing. We blew one, replaced it and it STILL SMOKED!  Pulled the whole top end apart, had everything checked out and found nothing. Pulled the turbo and found the seals were shot on the new one! The REP replaced it n/c, but I ate the labor. We could only figure the 'new' one had sat on the shelf too long and the seals had dried out.  :headwall:
Did it smoke on first start up when  the engine and components were still cold?  I would think the turbo would have to be hot in order to turn the oil into smoke but I dont know.  I'm going to be pulling the manifold to have it resurfaced and might send the turbo back to have them check it over.

Re: Lots of White Smoke

Reply #10 –
Quote from: The Soft Boulders –
  I would think the turbo would have to be hot in order to turn the oil into smoke but I dont know.  I'm going to be pulling the manifold to have it resurfaced and might send the turbo back to have them check it over.
Mine smoked right away. Would not hurt to have someone take a look at the turbo, though.

Re: Lots of White Smoke

Reply #11 –
If it's not losing oil , it is not the turbo . If it is not losing water, it is not gaskets. 
 The most likely smoke  source is the fuel . 

Re: Lots of White Smoke

Reply #13 –
Quote from: mike leary –
Mine smoked right away. Would not hurt to have someone take a look at the turbo, though.
The tech at the turbo shop said if there was no oil on the turbine wheels then the turbo was not leaking oil.  It's dry on both the intake and exhaust sides. 

Re: Lots of White Smoke

Reply #14 –
Thanks for all the good info guys.  I'm not sure how to do some of the things suggested so there's lots to research.  I haven't had any luck finding anyone that is interested in working on it but The shop manuals will be here Tuesday.

Re: Lots of White Smoke

Reply #15 –

Where are you?
Are there any bar rooms nearby, or a fire department?  I've had good luck mining bars for both info and labor.
The fire department may provide a diesel mechanic that wants to moonlight according to Pierce Stewart.

Re: Lots of White Smoke

Reply #16 –
Quote from: Travelin' Man –
Where are you?
Are there any bar rooms nearby, or a fire department?  I've had good luck mining bars for both info and labor.
The fire department may provide a diesel mechanic that wants to moonlight according to Pierce Stewart.
X2....I found a mechanic from the local City Dept. of Public Works that did great (cheap) work for me!

Re: Lots of White Smoke

Reply #17 –
I know ONE THING: with a smoking turbo you can drive from Arizona to Washington State with only pollution; no other damage. I don't think I'd drive to NAC unless I really knew what was what.

Re: Lots of White Smoke

Reply #18 –
Pierce's suggestion is an easy way to rule out  air in fuel issues.  Two gallon plastic fuel can, few feet of hose.  Change out fuel filters first if you haven't already done so. No diesel tolerates less than near perfect fuel delivery.

Re: Lots of White Smoke

Reply #19 –
Quote from: Protech Racing –
Faulty injector.
  Run a balance test. Let it skip long enough for the smoke to diminish.
I was thinking about pulling the injectors and sending them somewhere to be tested.  It would definitely help with the process of elimination anyway and it's something I feel like I might be able  to figure out how to do.  Does having the injectors tested sound like a good idea?