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Do all diesels smoke under load? I thought only old, knackered ones did but...

dug777

Lifer
:Q the Toureg moved like a scalded cat when the guy floored it turning onto the highway in front of me 😉

Golf was just pulling up the hill past me as i walked home, same with the Landcruiser (4.2TD), and they all had the same bluey smoke..

are they just fubared, or do all diesels smoke? I've never paid attention to teh farm utes (which we use because diesels run cool & you can use then on the paddocks)...
 
yes.

if you bog a diesel, they smoke like none other. it is one way to tell if someone has tuned their tractor, or semi at a tractor pulling competition, watch the smoke. if it billows out like a frickin cloud, dark black, that truck aint stock. but, any truck will do this when you put it in to high of a gear, and try to floor it. they dont bog out, but they get to rich.
 
Originally posted by: MIKEMIKE
yes.

if you bog a diesel, they smoke like none other. it is one way to tell if someone has tuned their tractor, or semi at a tractor pulling competition, watch the smoke. if it billows out like a frickin cloud, dark black, that truck aint stock. but, any truck will do this when you put it in to high of a gear, and try to floor it. they dont bog out, but they get to rich.

Cheers 🙂

I was pretty sure all three new cars couldn't be fubared...
 
Originally posted by: ballmode
I think that is a bad sign...

its an INTERNAL combustion... nothing should be coming out except the exhaust
So smoke from combustion of diesel fuel isn't exhaust?


Many trucks run straight pipes and they smoke all the time. Yes it's typical for diesel engines to smoke under load.
 
All diesels smoke. Some more than others due to adjustment. On my diesel MB, the proper 'tinker' way to tune the fuel/air mixture is to keep going until you produce a small cloud of smoke when you floor it from a dead stop.
 
Originally posted by: TitanDiddly
All diesels smoke. Some more than others due to adjustment. On my diesel MB, the proper 'tinker' way to tune the fuel/air mixture is to keep going until you produce a small cloud of smoke when you floor it from a dead stop.

that was what i saw with the toureg effectively...dayum it moved quick 😉
 
Originally posted by: dug777
Originally posted by: TitanDiddly
All diesels smoke. Some more than others due to adjustment. On my diesel MB, the proper 'tinker' way to tune the fuel/air mixture is to keep going until you produce a small cloud of smoke when you floor it from a dead stop.

that was what i saw with the toureg effectively...dayum it moved quick 😉

Yeah, hopefully the 'diesels are big, dumb, and ugly' public perception will wither and die.

They only get that way when you don't take care of them, but that's universal. 😛
 
Once up to operating temp, 185~200F, nah. Slight gray haze at most. In Europe they even use particulate filters on the exhaust that do need servicing.

Causes of Black smoke=Patrially burned fuel. Overfueling for more power, Clogged A/F causing intake restriction, bad turbo leaking oil into the intake(aggrivated by clogged A/F) This will add a blue haze to the black. An uber-clean intake impeller is a bad sign because it has been cleaned by leaking oil 😉 Low compression can add to this mix also.

Causes of white smoke: Unburned fuel as a result of cold running temps, worn injector nozzels(the .004~.006" holes erode from water in the fuel) causing the fuel not to atomize properly.

It's a long list I haven't thought about in years. Some ppl dump 10% waste lube oil into the diesel tanks to get rid of it. Not a good thing. Oils loaded with PCBs have been throw out this way*shudders*. Some folks run high sulfur agricultural fuel because it's not taxed but this loads an automotive engine up with solids in the chamber and on the injector tip, resulting in smoke. Industrial engines can get away with it because they are always under high load and not being light throttled.

What else you wanna know? I tuned and overhauled diesels for 30+years. I love'em.


...Galvanized
 
Originally posted by: SampSon
Originally posted by: ballmode
I think that is a bad sign...

its an INTERNAL combustion... nothing should be coming out except the exhaust
So smoke from combustion of diesel fuel isn't exhaust?


Many trucks run straight pipes and they smoke all the time. Yes it's typical for diesel engines to smoke under load.


I've dynoed 700+HP & 1300+#feet of torque diesels that just exhaust the slightest gray haze & heat. The haze can not be seen against the sky, only a black back ground.


...Galvanized
 
Originally posted by: GalvanizedYankee
Originally posted by: SampSon
Originally posted by: ballmode
I think that is a bad sign...

its an INTERNAL combustion... nothing should be coming out except the exhaust
So smoke from combustion of diesel fuel isn't exhaust?


Many trucks run straight pipes and they smoke all the time. Yes it's typical for diesel engines to smoke under load.


I've dynoed 700+HP & 1300+#feet of torque diesels that just exhaust the slightest gray haze & heat. The haze can not be seen against the sky, only a black back ground.


...Galvanized

A diesel dynoing 700hp should have double that amount of torque.
 
Not when they are set-up to run lean & clean.

Asshat drivers would remove the return fuel line(cooling fuel) and stick a rivet in it to jack fuel rail pressure. Get caught and your fired.

Cranes will over fuel for immediate torque for picking loads but they use #1 diesel fuel. It's clear as water, very dry with poor lubricity but burns hot n' clean. They still blow clouds of black till the turbo spools up. Work my share of those too. CAT bulldopzers also.

Have not worked many cars or light trucks with diesels.


Good night, Galvanized
 
Originally posted by: GalvanizedYankee
Once up to operating temp, 185~200F, nah. Slight gray haze at most. In Europe they even use particulate filters on the exhaust that do need servicing.

Causes of Black smoke=Patrially burned fuel. Overfueling for more power, Clogged A/F causing intake restriction, bad turbo leaking oil into the intake(aggrivated by clogged A/F) This will add a blue haze to the black. An uber-clean intake impeller is a bad sign because it has been cleaned by leaking oil 😉 Low compression can add to this mix also.

Causes of white smoke: Unburned fuel as a result of cold running temps, worn injector nozzels(the .004~.006" holes erode from water in the fuel) causing the fuel not to atomize properly.

It's a long list I haven't thought about in years. Some ppl dump 10% waste lube oil into the diesel tanks to get rid of it. Not a good thing. Oils loaded with PCBs have been throw out this way*shudders*. Some folks run high sulfur agricultural fuel because it's not taxed but this loads an automotive engine up with solids in the chamber and on the injector tip, resulting in smoke. Industrial engines can get away with it because they are always under high load and not being light throttled.

What else you wanna know? I tuned and overhauled diesels for 30+years. I love'em.


...Galvanized


Someone that knows what he's talking about.

My Ram 2500 diesel doesn't smoke when i'm pulling a load at full 20+ psi of boost.

I think it's this type of mentality that keeps the small diesel out of the US.


 
I never see smoke from my dad's, my brother in law's, and my uncle's diesels. They have a '99, '03, and '94 Dodge cummins respectively. Even with a light hop up on the latter two trucks, one of which IMPROVED gas milage.
 
My dad's diesel Tahoe smokes like a train when it's cold, or when your crusing on the highway, and you gun it to pass someone. We would laugh and say we are going to smoke em, literally. 😛
 
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