Diesel exhaust color meaning?

[BostonPatriot28]

I have a mixture of black and white depending on the temperature

 

[rustystud]

Well, here I go reviving another old thread. My Deuce(Non Turbo) usually gives a good puff of white smoke right as it starts, then idles with a light grey/blue haze. I figure the haze is mainly from the lack of turbo. When under throttle/load, there is always a good amount of blue/gray smoke that I also figure is from the lack of a turbo. I changed the oil last weekend and drove it around the ranch for about 1-1/2 hours and with the fresh oil, I ran it pretty good.(I didn't want to run it hard until I got fresh oil in it) I didn't abuse it but I gave it a good workout. Well, not like driving down the road, but Its all I can do until I get it registered. I'm still running seafoam in the fuel and I had been idling a lot while working on it these past months. At the beginning of last weekends driving the engine gave some great clouds of blue/grey smoke as she cleared herself out. After a few minutes, the smoke diminished a lot.(She hasn't ran this clean since I got her) However, I noticed the stack was literally "wet" after I parked it. I smelled the residue on the stack and it doesn't really smell like fuel, but it also doesn't taste like coolant. Could it be residue from the Seafoam? Do the non turbo multifuels wet stack more than the turbo charged ones? I'm hoping this is just the nature of the beast and not a problem. There is no rebuild tag on the engine and the block date is the same year as the truck so I'm assuming its the original. I want to have the injectors tested to make sure I don't have a leaking one, but the engine runs smooth and sounds great. It had a slight injector knock when I first got it, but it went away after I ran it a bit. I figure the Seafoam cleaned all the junk out. Also, the coolant and oil level doesn't seem to change. Should I be worried about the wet stacking? I realize the non turbo charged trucks are known to smoke like a house on fire so maybe I'm worrying too much. Thanks in advance.

You need to take it out and run it good and hard for over 1 hour (according to the TM's you should never idle for over 15min) .Then see what your stack looks. I'm worried about the "blueish" smoke. That indicates oil burning. Could be rings, or valve stem seals.

 

[Reaper651]

You need to take it out and run it good and hard for over 1 hour (according to the TM's you should never idle for over 15min) .Then see what your stack looks. I'm worried about the "blueish" smoke. That indicates oil burning. Could be rings, or valve stem seals.

I guess the bluish grey smoke is more grey than blue but I'm also a little nervous about it. I haven't noticed any oil loss though. What color smoke should the non turbo multifuel be? I know my truck's smoke reminds me of a non turbo 7.3L Ford diesel. I wouldn't hesitate to do an in frame on this motor eventually. Should I do a leak down/compression test when I have the injectors out to be rebuilt?

 

[61sleepercab]

Truck garages used to have a tinted glass "ruler" that had various shades of brown to black and was used to set pump output screw from the diesel trucks exhaust color.
B Model Mack operator/ mechanic reported that trucks can stand about a foot of fire out the stack on a hard pull but turning up the juice any farther will cook pistons . Mark

 

[rustystud]

I guess the bluish grey smoke is more grey than blue but I'm also a little nervous about it. I haven't noticed any oil loss though. What color smoke should the non turbo multifuel be? I know my truck's smoke reminds me of a non turbo 7.3L Ford diesel. I wouldn't hesitate to do an in frame on this motor eventually. Should I do a leak down/compression test when I have the injectors out to be rebuilt?

If you have the tools to do it I would. Just to see what the engine is looking like inside. I still would first take the truck out on a good hard run. This will also help reseal the rings if they have become glazed due to wet stacking.

 

[Reaper651]

If you have the tools to do it I would. Just to see what the engine is looking like inside. I still would first take the truck out on a good hard run. This will also help reseal the rings if they have become glazed due to wet stacking.

I am going to test the injectors here pretty soon just to see what they spray like. I'm trying to rig up an adapter for my compression/leakdown tester. My pop tester is ready to go though. I just watched a Youtube video of a non turbo M35(Also a 1971 with a White Engine) driving and now I'm really concerned as the one in the video actually produced blackish smoke on acceleration but also smoked more than mine at idle. My truck still has a bit of idle surge when cold but it seems to be getting better. I will definitely take it for a run just as soon as I can register it. Oh the money pit is getting deeper... Thanks for the help.

 

[61sleepercab]

Make sure you have clean fuel filters..... a B model Mack of mine woke up when she was running without an inch and a half of coffee grounds up the side of the filter.She went from no smoke to a light brown on acceleration. Mark

 

[Reaper651]

Make sure you have clean fuel filters..... a B model Mack of mine woke up when she was running without an inch and a half of coffee grounds up the side of the filter.She went from no smoke to a light brown on acceleration. Mark

Yep I just changed the fuel filters and yes the old ones were military filters and clogged badly. Especially the primary. The truck wouldn't idle at all before I changed them. After changing them and the fuel, and adding seafoam, the truck would idle but only at about 400RPM. I then turned up the idle 1-3/8 turns, and now she idles good when warm, but when I first start it, the idle surges a bit until its warmed up but seems to be getting better. I'm still running Seafoam in the fuel and every time I drive it, the engine seems to be running smoother than before. It fires right up now too. It sat for about a month, I checked for hyd lock, then just touch the start button and it pops right off. Hopefully its just still waking up after sitting for 7+years. Thanks for the help.

 

[rustystud]

I am going to test the injectors here pretty soon just to see what they spray like. I'm trying to rig up an adapter for my compression/leakdown tester. My pop tester is ready to go though. I just watched a Youtube video of a non turbo M35(Also a 1971 with a White Engine) driving and now I'm really concerned as the one in the video actually produced blackish smoke on acceleration but also smoked more than mine at idle. My truck still has a bit of idle surge when cold but it seems to be getting better. I will definitely take it for a run just as soon as I can register it. Oh the money pit is getting deeper... Thanks for the help.

Yes they are money pits. I used to think boats where bad, but now with my "green friend" I truly know what a money pit is ! But I cannot stop !!!!

 

[Reaper651]

Yes they are money pits. I used to think boats where bad, but now with my "green friend" I truly know what a money pit is ! But I cannot stop !!!!

HaHa I agree. I keep adding things to the "Bring to A1 condition" list and then I see the price of each project and wonder how I will ever get this truck going. I then start to wonder if I should just sell it to someone that could actually afford to work on it... Then I drive it around a bit and decide I'm never going to sell it!! Its MINE!! I saved it from the cutting torch when everyone said I was crazy!! So I can't stop now!! Well, I figure, save up, do a project. Then save up and do another. It really doesn't need a ton of work but the few things it does need(clutch, tires, possibly RR the engine) are expensive. I just hope I don't have to RR this engine for a while. But lets face it, Deuces are so much cooler than the normal off road type vehicles of today. Thanks for the help everyone.

 

[rustystud]

HaHa I agree. I keep adding things to the "Bring to A1 condition" list and then I see the price of each project and wonder how I will ever get this truck going. I then start to wonder if I should just sell it to someone that could actually afford to work on it... Then I drive it around a bit and decide I'm never going to sell it!! Its MINE!! I saved it from the cutting torch when everyone said I was crazy!! So I can't stop now!! Well, I figure, save up, do a project. Then save up and do another. It really doesn't need a ton of work but the few things it does need(clutch, tires, possibly RR the engine) are expensive. I just hope I don't have to RR this engine for a while. But lets face it, Deuces are so much cooler than the normal off road type vehicles of today. Thanks for the help everyone.

I never wanted to be a "cookie cutter" 4X4 owner. Now with the Deuce I'm a member of an elite few !