Exhaust Soot
 

Lately I've noticed quite a bit of black soot coming out of my exhaust when I start the engine(84 300D turbo). This usually happens if the car has been sitting for a couple of days. The car doesn't smoke when driving, so I'm wondering if this is normal, or if there is something I can do to correct this problem? It does cause a little mess on the garage floor. I'm fairly new to diesels and don't have much, if any expierence with them, so any advice or help would be appreciated. Thanks!

That is classic valve stem seal leakage.
Cheap to replace..
but tedious... but it is up top so not as bad as some jobs...

how old is the car? could just be suit built up in the muffler.

My 82 has 204k and on startup also produces a sooty spot on the ground.
I had been told that it was unburned fuel resulting from a cold engine and once warm is gone.

Yep. Cold old engines usually make a black spot.

Indeed, mine does! :D

When I start mine on a cold morning, (like I did this morning) it will start up with a small puff, but after I back out of my space and hit the throttle, it gives a small stream of black, then goes clear. :D

I'm sure you have more in your life to worry about than that. Just drive it......;)

Well that may be so, but my 12,000 mile Metric Motor engine shoots out soot and I`ll be danged if I`ll be changing out the valves seals anytime soon :rolleyes:.

I agree with JIMMYL, bigger things to worry about and just drive it. all diesels produce soot, they just mark their territory. be glad you aren`t marking it with oil ;).

Put an old piece of cardboard down under the exhaust in the garage.

Charlie

I'd try running a couple of cans of Lubra Moly Diesel Purge. It stops my cars from smoking.

It wouldn't if you use good fuel. I suggest finding a better fuel station.

It wouldn't if you use good fuel. I suggest finding a better fuel station.

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In actual fact, since they changed the formula for Diesel, neither car smokes much. But I have noticed that over a period of a year or so, both cars tend to become sluggish, and if you rev up the engine rapidly, there will be black smoke, only occasionally useful for the edification of imbeciles who like to honk strenuously after you have already begun to pull away from a light. But I digress.

When the engine does get sluggish, I have found that a thirty minute 1½ can of Lubra Moly ends all smoking and perks up performance quite noticeably. As for the brands of fuel, I use Valeo, Mobil and occasionally Exxon brands. Texaco makes claims about "Premium Diesel", but I have not noticed even a small bit of performance, not before with the old high sulfur fuel or now, with the low sulfur fuel.

I bet your Diesel would also run better after a Diesel purge. Diesel Giant shows how to do this on his website.

I have run both cars on 99% Biodiesel and they run smoother and quieter, with a slight (5%less) decrease in mileage.

Just for curiosity, what do you consider a "good fuel"?

Is smoke a turbo thing? I've had my NA 240 for about a year now and not seen any smoke at all from it. I use corner store diesel and WVO, never used diesel purge and I haven't done engine work yet. Also, on this subject, I did look at another 240 that had smoke coming from the ENGINE COMPARTMENT. It ran alright, but I wasn't sure what was going on. Exhaust leak?

Tennessee is full of tailgaters.I once in awhile fill my glasspack with water.Then drive and wait for a tailgater.If its a white following me its fun when I mash the pedal.Blows out all the soot,with modified tailpipe no mess on my car.
Yes I suffer with deppression,and carry a gun.

Nice. :D :D

Humm, a year also happens to be the adjustment interval for valve lash. Coincidence? ;)

Humm, a year also happens to be the adjustment interval for valve lash. Coincidence?

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The 1990 has automatic adjustment on the valves.

I adjusted the valves on the 85 300TD about 7,000 miles ago.

I generally get Diesel at Exxon and Mobil stations. I always go for the lower price (the stations with the highest prices will naturally have the lower volume, and the greatest likelihood of stale fuel and water in the tank), and avoid Shell and BP, which always charge rather a lot more, more than would be offset if I didn't use the Diesel purge.

Most Diesel is sold to trucks, and unless the trucker has a company-issued card, he he not going to pay 15 cents more per gallon for a 100 gallon fillup. The stations here in Miami with the highest prices are in less traveled areas, and are apparently refusing to lower prices until they fill the tank again. The longer it sits, the more condensation gets accumulated in the tank, the more likely there will be algae, and $2.50-$4.00 a gallon for water is more than I am going to pay.

When I used a Shell station exclusively for six months running (it had recently opened and had lower prices to compete), the last tank I bought filled up two of the plastic filters with gooey, sticky tar. I wrote Shell several times and got zero reply, so I cut up their card and sent it back to them.

I quit using Weststar when they sold me a tank with a lot of water in it, and there was no one who would do anything about it. Wherever Westar's main office is, it is extremely well hidden.


Do you use Diesel Purge once a year? Unless you do, I don't think that your interpretation of the purge I use turning black is more than speculation.

I ran both cars on Biodiesel 99 for over a year, stopping in July 2008 when the station went out of business. The brand of fuel does not seen to make any difference. I run 1 1/2 cans of LubriMoly as per the detailed instructions on Diesel Giant's website, rev the motor until it ceases all smoking, and the liquid left behind is always black. I think this is normal and to be expected. And the cars ALWAYS run noticeably better and get better mileage by something around 10%.

I don;t think that there is any way for the consumer to know what the quality of the fuel is. Price is not an accurate index of quality, and of course, you can't even see the fuel. Up through the early 50's, they had those pumps that would fill a glass reservoir at the top and you could see it before it went into the tank. If it were not for the county government, stations would not even be posting prices.

I buy safeway diesel.. its cheaper than gas! plus 10% bio.. I feel that the price is a good reference of age of diesel in the tank, and that the age has alot to do with the quality..

Im sure most people go for the cheap diesel..

Just did a purge on my 240 that has never had a purge in that engine's 6 years, 50k+ miles of my ownership. It just turned green from the leftover diesel mixing with it and the 1-year old primary filter was still clean.

I use ULSD from a high-traffic truck stop that is supplied by the Suncor refinery 10 miles away.

I think that if your purge did not turn dark during the process, it is likely that you didn't really need a purge. The quality of the fuel could be a factor, but it is not the only factor. Injectors and the type of driving you do are among other factors. This is not to say that doing a purge was not a good idea. It is unlikely to hurt, and normally perks up performance. I do a lot of stop and go driving around town, and make few long trips at over 65 mph.
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If Safeway (or anyone) were selling Diesel or 10% Biodiesel for less than regular, I would buy their fuel as well. At the moment, Dino Diesel is selling for $2.19-$2.30 range at the high volume stations, which is about 5¢ less than High test gasoline, and 7¢ lower than RUG.


Is Safeway the same company as the supermarket chain? They do not have any stations here.