Two Questions: Smoke and Glow

[regsatx]

Hello All!
TWO QUESTIONS:
1. Why is it that on some days...like today, I get more smoke on acceleration? For the past week, I saw little or no smoke. Today, I'm getting a puff and whisp of sooty, gray/black smoke when taking off from every stop. Nothing intolerable, but considerably more than I've gotten for past week or so. I know I'm due for an oil change (it will be my first on it with about 3100 miles on present oil; will change next week and will start using Delvac 1300). Previous owner used Valvoline 20w50 (which is in car now); could this be a factor in smoke? I've been adding about 4-6 ounces of Power Service to fuel at fill up since I've had car. Just wondering if there's any rhyme or reason to this? This has happened before since I got car...one day hardly any smoke no matter how hard I drive, other days I consistently see it on acceleration.

2. Glow Light. Of course when starting first time of day and after sitting for a while, I wait for glow light to go out. If I run in to pickup dry cleaning or even shop at supermarket when, like today, it's in the 70's, I just start right up. Is there a rule of thumb on when to wait for glow light to go out?

UPDATE:
Well, I've had the car for two months now. I spend $2000 on it and have spent another $1200 to $1500 on new injectors, transmission modulator and servo, rear brakes, valve cover gasket, tax registration, etc. Even with all of that...I TRULY LOVE THIS CAR!!!! The weight of it, the style and character, even the smell. I see how these cars get under one's skin!
Sure, I still need to fix the cruise (HAS ANYONE USED COLD SOLDER TOOL ON CRUISE AMP?), the trip meter works erratically, and my antenna won't go up, but that's it! And thanks to the great people on this board...I have a handle on those things. My car is very clean runs fabulously...superb power, smooth quiet, and gets great mileage!
FROM A GRATEFUL NEWBIE – THANKS FOR ALL THE HELP AND ADVICE!

Reg
1985 300SD Astral Silver - A Beauty!
227K

[BrierS]

Question #1 should bring several to help. I know with my '87 300TD I get smoke after making a number of short trips if I don't flog on it now and then between these short trips.

Question #2 brings the manual into play though I am not going to pull it out and read what the temperatures are when longer GP waits are suggested. What I have learned is that once these engines are run to normal operating temperature they will fire w/o GP doing anything. On the opposite end, cold starts in freezing temperatures call for 30+/- seconds and even sometimes a second GP cycle (turning the key off completely and then turning to the GP light on again).

Don't know if this helps but at least it will be some reading material until the seasoned vets get in on this.

[Pete Burton]

1. Use diesel purge, that should help. 2. Steve's right about glowing more when it's colder. Check the glow plugs, too. The glow plug relay circuit uses a funky current balancing circuit that compares current to #1 plug to the average of #2-5. Depending on the version, it doesn't come on if it's NG, or it blinks, or something like that

[PatrickW]

Originally Posted by regsatx

Is there a rule of thumb on when to wait for glow light to go out?

I wait until the seat belt buzzer stops. Sounds crazy, huh?

Actually, the seat belt buzzer has nothing to do with the glow plugs - but as I understand it, the glow plugs continue to heat for a short time after the glow light shuts off.

I've been able to start my car quickly in temperatures well below freezing. I live in MN, where it's colder in June than some places are in January.

- Patrick

[westkill]

I tell my wife to use the seat belt buzzer as her guide to. It was just easier to tell her when the buzzer stops, crank away.

[Jim H]

86 SDL, I wait for seat belt buzzer and SRS light to go out. It's about 5-10 sec after glow light goes out.

[psfred]

Diesel fuel is pretty variable -- what you put in the tank one week from the same station may not be what you get next week, and some fuels will give more smoke than others.

Lots of slow stop and go driving will result in excess smoke when you stand on it because soot is accumulating in the exhaust -- it all blows out at once when you wind it up under load. My brother's 300SDL is really bad about this since my sister-in-law is a fairly sedate driver.

Some smoke is normal, expecially on 61x engine. later ones smoke less.

These are great cars, enough so that most of us will put up with the maintenance and repair expensese of old ones!

Peter