Smoke Problem Going Downhill in Gear

dturner01

New Member
Joined
Sep 13, 2009
Messages
3
Reaction score
0
Your Mercedes
220E 1994
HI. Have a 220E 1994, 138,000 on clock. When going down hills slowing up in gear the exhaust releases white smoke. At the bottom of the hill when pulling away the engine releases more smoke, then it clears up. No smoke as you go on level roads or go up hills. Compression test says all OK. Any ideas? :confused:
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
332
Age
86
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
This will be wear in the valve guides, and not the bores,,if the oil consumption is not that high it is nothing to worry about
 

ncooper

Senior Member
Joined
Apr 29, 2009
Messages
421
Reaction score
0
Location
York
Your Mercedes
1984 Mercedes Benz 280 SL,1993 Mercedes Benz 190E Manual,1993 Mercedes Benz 190E Auto
Possibly worn valve guides or valve stem oil seals or one or more broken oil control rings?
When going downhill,the engine is not burning the oil fully,allowing it to build up in the cylinders.
When you re-apply the throttle,it then burns the oil off and the smoke clears.
Last car I owned that did this was an Austin Maxi!!
(Disclaimer:I may be entirely wrong:))

Regards,
Nick.
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
332
Age
86
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
Possibly worn valve guides or valve stem oil seals or a broken oil control ring?
When going downhill,the engine is not burning the oil fully,allowing it to build up in the cylinders.
When you re-apply the throttle,it then burns the oil off and the smoke clears.
Last car I owned that did this was an Austin Maxi!!
(Disclaimer:I may be entirely wrong:))

Regards,
Nick.

I think that you are entirely right ;):D
 

ncooper

Senior Member
Joined
Apr 29, 2009
Messages
421
Reaction score
0
Location
York
Your Mercedes
1984 Mercedes Benz 280 SL,1993 Mercedes Benz 190E Manual,1993 Mercedes Benz 190E Auto
Snap:lol::lol:,almost.

Regards,
Nick.
 

Axcontrols

Active Senior Members
Joined
Nov 1, 2006
Messages
211
Reaction score
25
Your Mercedes
53 ML 270CDI, 2017 GLA200d, 1998 BMWZ3
When you're crusing along their isn't much vacuum in the airfilter/inlet manifold etc so any oil chucked up by the engine breather into the inlet stream just sits there either in the airfilter or lurks there stuck to the sides of the inlet manifold. On a long run at cruising speed it can build up quite a lot and when you suddenly lift off the gas pedal that creates a lot of vacuum in the manifold dragging all that dross into the cylinder where it burns with a big puff of smoke. Although usually blue/black rather than white but then maybe it's different nowadays.
 
Last edited:
OP
D

dturner01

New Member
Joined
Sep 13, 2009
Messages
3
Reaction score
0
Your Mercedes
220E 1994
  • Thread Starter
  • Thread starter
  • #8
Valve Guides or Valve Stems....

Thanks for the info. Would this be caused either by the following and would only happen when going down a hill in gear. It does not happen when in neutral. Also the car behind said the smell was rank. The smoke can be blue and light black, not white.

-valve guides or valve stem oil seals or a broken oil control ring

The replies to this thread have been consistent and I need to know is this a job / repair I should get sorted asap or can it wait?

Thanks for all your help.
 
OP
D

dturner01

New Member
Joined
Sep 13, 2009
Messages
3
Reaction score
0
Your Mercedes
220E 1994
  • Thread Starter
  • Thread starter
  • #9
Thanks for your reply. Would or should this show up on a compression test. The garage told me that the compression is fine, valve stem oil seals are good and rings are cool but did not mention the guides. Will go back and ask them.
 

ncooper

Senior Member
Joined
Apr 29, 2009
Messages
421
Reaction score
0
Location
York
Your Mercedes
1984 Mercedes Benz 280 SL,1993 Mercedes Benz 190E Manual,1993 Mercedes Benz 190E Auto
Thanks for your reply. Would or should this show up on a compression test. The garage told me that the compression is fine, valve stem oil seals are good and rings are cool but did not mention the guides. Will go back and ask them.

To do what you describe,excess oil must be getting into the cylinders.
I'm not sure how,without dismantling the engine and examining them,a garage could pronounce either the valve guides or valve stem oil seals to be worn or not.
I don't think a broken oil control ring would show up on a compression test,but I stand to be corrected on this.

Perhaps your best option would be to have the crankcase checked for pressure and the ventilation system thoroughly overhauled first(as per Axcontrol's post) ,this is relatively simple and therefore cheap.

If the problem persists,then the other possible causes would require investigation.

Regards,
Nick.
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
332
Age
86
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
It is as nick has said,,if it is only using say one liter between services that is fine,,once this happens, the wear rates slow right down, owing to the extra lubrication that is taking place, and the cost of fixing is far beyond the cost of any oil
 

kth286

Senior Member
Joined
Nov 4, 2002
Messages
3,067
Reaction score
2
Your Mercedes
E320 Coupe 95
For me, white smoke is indicative of a headgasket problem between coolant passage and combustion chamber.

You could look at the oil dipstick for signs of 'light creamy coffee colour'.

A cylinder compression test, whilst looking at the coolant header tank level will indicate problems if there is air bubbling out of the coolant tank.
 


Chris Knott Insurance, see oursticky posts here!
www.ckinsurance.co.uk
Top Bottom