It was a quite weekend for me, (that doesnt happen often).
Anyway, I had the time to sit and watch the kids play. While I was out, my neighbor started and warmed up her Powerstroke, then drove off.
Within 30 minutes, another neighbor got in his 93 Dodge CTD, warmed it up, drove off.
Both of them (obviously diesels) had a very different smell of diesel to them.
After thinking about this a while I realized that my trucks exhaust often smells a little different based on engine temps.

What causes the different smells for diesels?

Could it be based on displacement of the cylinders and/or timing?

Rich.

 

I think its the difference in Timing cause higher timing makes the cylinder pressure higher so it burns different. (I think thats the way its goes)

 

I hooked a loaner Superchips programmer on mine last weekend.
Supposedly adds HP by changing timing
(kinda like an EZ, but changes the program of the ECM/PCM so you don't leave it hooked up)

Didn't see any HP gains, but did notice the engine sounding different, from the timing I suppose, and noticed the exhuast didn't smell "right".

My vote goes for different ignition timing as well.

Ran it for a couple days, then returned to stock.
Didn't see HP gains, and didn't feel right about what it did to engine sound and smell.

phox

 

Wondering if a catalyst will make it smell differently? I know the old farm tractors and my IDI 7.3 had a bit of a sweet smell to it. My TDI VW will burn the eyeballs outa ya. My CTD smells just right.. (my neighbor whom I don't get along with at all mentioned one day she hates the diesel smell. So you know which way I idle the truck in the morning. ;D )

 

Ive noticed that my current truck's exhaust smell much different than my previous GMC with the 6.2L diesel.

Perhaps is a combination of how much volume each cylinder has, (volume of both air and fuel) and timing?
The above attributes will affect the characteristics of each combustion cycle.
Perhaps its the difference in burn thats making them smell different


???

Rich

 

Ive noticed a much stronger smell in the winter when its really cold (ie -30 or colder).

 

Funny you should mention that! I always liked the smell of the Diesel burning in a Greyhound Bus. It was kind of a sweet smell. The smell of my CTD is different. It's almost a sour smell, kinda like a gasser with a cat conv.

I know, I'm sick.

 

[quote author=Dr. Evil link=board=8;threadid=19966;start=0#msg187974 date=1064284272]
Ive noticed a much stronger smell in the winter when its really cold (ie -30 or colder).
[/quote]

Could it be that the cold air (being more dense) increase the amount of air in each compression cycle?
That additional volume of air (Because the air is more dense) changes the burn characteristic, thus the smell is a little stronger?


Your not alone in you "sickness".
I too like the smell of many trucks/busses... and yes, our trucks do smell different.

???

Rich.

 

Good Lord!!

Next thing we will be like dogs in the park sniffing each others..ummmm....tailpipes...

 

[quote author=spots link=board=8;threadid=19966;start=0#msg188292 date=1064356504]
Good Lord!!

Next thing we will be like dogs in the park sniffing each others..ummmm....tailpipes...
[/quote]

 

I love the smell of diesel in the morning, it smells like....victory. ;D

 

I'm going to take a poke at this. Could it be the glowplug motors with pre-combustion chambers burn differently than the direct injection motors? As far as the Greyhound, the 2 stroke Detroits always had a unique?? smell. Maybe 'unique' is the wrong word, but you know what I mean! I don't know about the TDI, I am a semi-retired air cooled VW guy and got out of the biz in 1998 before they came out. I do know they are a far cry from the old Diesel Rabbit. I'm glad they finally got that figured out. Jim

 

TDI's started in '96 in North America. I think you may be onto something with the direct injection thing. I also believe the richer the diesel the sweeter the smell. Just speculation tho...

 

[quote author=spots link=board=8;threadid=19966;start=0#msg188292 date=1064356504]
Good Lord!!

Next thing we will be like dogs in the park sniffing each others..ummmm....tailpipes...
[/quote]

You'll be quite the "Diesel Expert" if you could tell someone what their timing is set at by sniffing thier tail pipe!


You may be right about the method of injection having something to do with it.
Id also agree that it has something to do with mixture of air to fuel and when the burn happens (timing).

I dont really know.
Rich.

 

[quote author=DPG link=board=8;threadid=19966;start=0#msg188328 date=1064360420]
I love the smell of diesel in the morning, it smells like....victory. ;D
[/quote]
If you drive a Ferd it might be. Because you got it started
DM01 ;D