Strange Smoke
 

Hi,

I have a problem with my '72 280SE 4.5 (108). It runs with absolutely no (visible) smoke and I recently comletely readjusted timing and mixture and all that so it is running nicely.

However, whenever it is cold, after driving 4 blocks or so, it suddenly throws huge clouds of white smoke for about a 5 seconds or so. And I really mean huge ... the two cars behind me go blind ... :(

After this, it is completely over, no more smoke and fine driving. It always happens at the same warm-up temperature, I can already tell the trafic light where it happens when starting from home ...

Has anybody any idea what this could be ???? ... it is really embarrasing :(

Thanks

Stefan

'72 280SE 4.5 - Herr Mueller

You may want to do a search on this website using the term: transmission modulator

Its not the transmission modulator
 

Hi Paul,

thanks for the suggestion but this was already checked. Would that explain why there is only a one-time smoke plum?

If so, I might check it again since I did not do it myself

Stefan

While white smoke can be indicative of coolant entering the cylinders, it can also be from burning transmission fluid, thus the thought about a bad diaphragm in the modulator.

You made no mention of rough running or overheating, which steered me away from the engine and towards the transmission. I assume that every bit of the smoke is emanating from the tailpipe and none from under the hood, if so, that would argue against some type of external fluid leak coming in contact with a hot exhaust pipe.

How are fluid levels? Anything low?

Hard to diagnose through a modem...

I had the same problem when I first purchased my car. I have an automatic transmission and the vacuum operated diaphram was deteriorated causing the vacuum to suck transmission fluid into the intake maniflold. Once the car was warmed up and driven a short distance it used up the pooled fluid and the white smoke disappeard. Replacement cost $19.

Beautiful car, Gregg.

More info
 

Hi Paul,

even though you are diagnosing through a modem, you seem to have a very good feeling for the problem since some of your new questions "hit the mark". Thanks a lot so far.

1) Actually, engine oil and transmission oil was to low. (I have a transmission leak at the converter gasket which I do not tackle right now since it would make sense to combine it with rebuilding the tranny and this is a rather large sticker ...) I filled it up yesterday and there was no smoke today, but it could be accidental.

However, does your question point at something specific? I can not imagine low fluids generating the smoke ...

2) Sometimes, I have the smoke coming from under the hood as well, but not always. However the majority comes from the exhaust pipes and not from somewhere under the car.

I am curious what you had in mind with the questions ..

Thanks a lot

Stefan

I was just employing some rough deductive reasoning. If the smoke is coming from some type of fluid leak or fluid consumption, then fluid is being lost from the tank/reservoir/sump that holds same.

Your transmission leak plays havoc with this reasoning relative to transmission fluid consumption.:(

Sounds like maybe some tranny fluid is dripping onto the exhaust, could it be the pan is leaking?

Or does it come out the pipe?