My 74 240 D (pearl) engulf herself in white smoke at idle and when I let off to shift or going down hill but shows little or no smoke under power as I have followed her in my lovely 81 sd (Bell)?

William Rogers....

How is the oil consumption? I'm wondering if lube oil is being added to combustion oil creating white smoke at low power settings and burning off at higher power.

I'm also assuming that it's white/very light blue smoke and not steam/water vapor from a coolant leak into combustion chamber(s).

That's my first guess.

BCingU, Jim

When a car starts to smoke in a white way, there normally is a water leakage; the white smoke is a sort of steam.
When a car is burning the motoroil, the smoke behind the car should be bleu-ish...

....or....

__________________
1990 300SL-24
1993 C250D with a minor 600+k kilometer
www.MBenzNL.com(the Netherlands)

Here are some things to check from my diesel engine repair manual.

It says the most likely cause is timing retarded, followed in second place by the following possible causes:

-loose timing chain
-restricted fuel return line
-air leaks in suction lines(fuel)
-restricted fuel line or filter
-injection pump
-wrong grade of oil for ambient temps.
-glow plugs inoperative

I always thought white smoke was fuel related.

I would also check for restricted air filter. On the Detroits I used to work on, if the manual shut down was tripped (this cuts off air flow through the blower), and you tried to start it, there wiould be copious amounts of white, raw diesel smelling smoke. I imagine a very dirty filter could cause similar symptoms, while allowing enough airflow to still run.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

I have years of experience working on gas engines just finished building a 454 powered 2wd Blazer for my wife Ha Ha ,but these two Mercedes are my first go at diesels can't imagine ever driving anything else, If it is timing can I play around with the timing with the engine running like I would with a gas engine?
Thanks for all the input William Rogers

1974 240 D
1981 300 SD
1981 k5 454 Blazer

I am assuming you are referring to Patsy's post on the most likely cause for white smoke, which was "timing retarded" I am thinking that the book is referring to the valve timing, and not the injection timing. If you do a search on the subject of timing chain, and timing chain stretch, you will find info on how to check the valve timing, and checking for timing chain stretch...(seeing as your 240 is "aged" I am assuming it has many miles, and may be suffering from such an ailment.

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

Thanks Larry for clarifying that. It is a reference to valve timing not injection timing.


[Edited by patsy on 01-24-2001 at 08:56 AM]

Thank you all for you thoughful replies this is the first M B site that I have found that gets replies .
William Rogers..

74 240 D
81 300 sd
81 k5 454 conversion
thats to pull my firewood trailer

In diesels white smoke is not normal, even on cold morning startups like gas cars sometimes. Are you getting film on the inside of the windows when you activate the heater? Check the oil dipstick to see if it looks normal or is it sort of milkshake looking? Also, check the coolant reservoir to see if it is proper coolant color or is brownish. Abnormal appearance or the inside fogging would suggest either the coolant is leaking into the oil or vice versa. Get it checked out thoroughly.

__________________
Douglas
1959 M-B 220S cabriolet

there is no coolant loss and oil is normal black diesel looking ,there is little or no smoke under power , but great cloud at idle (GREAT CLOUD!!!!) and going down hill with foot off accelerator........
William Rogers....

Lets refine this a little further.

Is the smoke heavy ANY time it's idling, or only when idling after start-up? Could the smoke be a pale blue rather than white?

Your additional statement about smoke when coasting down hill, foot off the accelerator, plus the idle smoke, has me thinking valve stem seals, especially if the smoke is present at idle only after start-up (as opposed ti idling with the engine off ).

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

yes the smoke is heavy at idle after warm up as well as start up.......
William Rogers........

I have heard a leaky transmission vacuum modulator can also cause billowy white smoke in gas cars. Some one else should jump in on this before you spend too much time considering this idea!

Deezel. your point about the trans modulator was very good, and momentarily a lightbulb lit up over my head, but then quickly faded when I remembered that he has a 240D and most likely a stick. I searched his posts, and he does elude to having a stick by stating that he gets the smoke while letting off to shift. Bummer, for a moment I thought you had it! Sure sounds like oil is being sucked from somewhere though One idea...use clear vacuum line and stick a section of it in areas most likely to cxome in contact with oil...if the tubing gets groady, you're one step closer for little $.

-Larry

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D