I recently noticed a little bit of black smoke out of the tailpipe when accelerating forward after backing out of my driveway (the engine being cold). I have not really noticed this under any other circumstances. What are the most likely causes of this phenomenon in a 1981 240D, and what (if anything) can I do to mitigate it? I recently changed the air filter, so we can probably rule that out, as a cause. Any thoughts?
Cold engine, black smoke
1 - 5 of 5 Posts
Is the smoke clearing up after the Engine is up to operating temp and has been driven around for some time?
When you first start hold a piece of cardboard near the exhaust. Remove it and smell it and see if it smells like Oil or Fuel.
A Valve adjustment and re-timing your Fuel Injection Pump are low cost things that might help and something to do before you rebuild Injectors.
If it has a oily smell it could be the Valve Stem Seals are allowing a little oil to get in.
Does it put around Town all of the time or does it get out on the highway where you can do say 60 miles per hour for like 30 minutes or so.
If you don't get out on the highway you might try that and see if the symptoms improve or go away.
Steep hills will also work.
If the car sat unused a long time; my Volvo Diesel sat 1 year. After getting it going it had hazy gray smoke all of the time. It turned out the Rings must have been sticking. I removed the glow Plugs and dumped in Marvel Mystery Oil into the Cylinders and let is soak a week. Rotated the Engine and poured some more in and let that soak for 3 days.
I drove it around the corner to my Drive Way and changed the Oil and took it for a rid on the freeway. There was a noticeable difference in the smoke and as the days past it got less and less.
When you remove the Oil Fill Cap what do you have a lot of blow by?
When you first start hold a piece of cardboard near the exhaust. Remove it and smell it and see if it smells like Oil or Fuel.
A Valve adjustment and re-timing your Fuel Injection Pump are low cost things that might help and something to do before you rebuild Injectors.
If it has a oily smell it could be the Valve Stem Seals are allowing a little oil to get in.
Does it put around Town all of the time or does it get out on the highway where you can do say 60 miles per hour for like 30 minutes or so.
If you don't get out on the highway you might try that and see if the symptoms improve or go away.
Steep hills will also work.
If the car sat unused a long time; my Volvo Diesel sat 1 year. After getting it going it had hazy gray smoke all of the time. It turned out the Rings must have been sticking. I removed the glow Plugs and dumped in Marvel Mystery Oil into the Cylinders and let is soak a week. Rotated the Engine and poured some more in and let that soak for 3 days.
I drove it around the corner to my Drive Way and changed the Oil and took it for a rid on the freeway. There was a noticeable difference in the smoke and as the days past it got less and less.
When you remove the Oil Fill Cap what do you have a lot of blow by?
Thanks for the feedback. I will definitely work on implementing some of these suggestions.
In answer to 300Dman's questions, I have only ever seen black smoke with a cold engine. I have, at times, noted gray/white smoke on acceleration, it is not a consistent occurrence.
In the past four months, most of my driving has been either in town, or on the country roads near my home. I have not been traveling any distance at freeway speed (though I am hoping to drive up to Oregon next month).
I do see indications of blow-by. This is not new.
Thanks again.
In answer to 300Dman's questions, I have only ever seen black smoke with a cold engine. I have, at times, noted gray/white smoke on acceleration, it is not a consistent occurrence.
In the past four months, most of my driving has been either in town, or on the country roads near my home. I have not been traveling any distance at freeway speed (though I am hoping to drive up to Oregon next month).
I do see indications of blow-by. This is not new.
Thanks again.
1 - 5 of 5 Posts
