Hi,

What does it mean to see smoke at full throttle? Is this just what always happens, or dies it indicate that things are getting cleaned? I ask this because my father, who has been driving my 300D has been putting gulf diesel into it. It is just a station, not a truckstop, but has some heavy trucks sitting around, so e figured it has good thruput. I never noticed any smoking or anything, and even got a record gas mileage using that diesel, 33.9 MPG. I filled it up sunday night with flying j diesel, and added some rotella DFA additive(my father never added anything to the fuel. The flying J fues foamed up and I figured it was good fuel, but now when I accelerate hard, I see a large cloud of black smoke and then a trail as I go along in my rearview mirror.
Both the gulf and flying J suppoedly have cummns L10 cleaning capacity, as does the rotella DFA.
One other thing that I noticed is that when I did my oil change, I must have added too much, as the level is about 1/8 inch over the full mark. COuld the smoke be due to oil burning, where it gets trapped in the cyllinder at high ropms, but oozes out at low ones?
Any info would be most appreciated. Thanks

John

John,

I've read a lot of posts about smoke. One long series seemed to arrive at a consensus that you should not see much smoke in day time under full throttle....just a bit in the mirrow. At night, of course, the lights from cars behind you increase the image.

My car runs perfectly and uses virtually no oil. I know that it is in good condition but it does smoke a good bit when I push it. Other than the impact of person behind me, I don't worry much about it. On the other hand, I am sure that "new" smoke can indicate something is amiss.

One thing many forum users emphasize is the value of periodic injector cleaning. Lube Moly makes a product that goes directly into the injectors (not through the tank). You disconnect the lines to and from the injector pump (fuel circulates and does not burn all at once) and cycle a can of that stuff until it is gone. Apparently, that cleans the injectors very well and reduces smoking. I'm gonna try that this weekend.

Nic
'95 300CD

John,

You are fine. The excess oil may be a factor, but some smoke at hard acceleration is likely carbon build up being forced under heavy load and plenty of heat - this can be a good thing.

Nic - I assume your sig should read '85 300CD.

__________________
Chris

'04 ML500 - 53k, Inspiration Edition, Desert Silver
'11 Audi A4 Avant - Brilliant Black
'87 300SDL sold
'99 C280 Sport sold
'85 190E 2.3 sold