Blue/gray smoke
Thread Starter
Almost a Member!
Joined: Oct 2002
Posts: 47
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From: Santiago, Dominican Republic
E420 Sport
Blue/gray smoke
When I step on the gas in my gasoline 1990 300E 80K miles and the car goes from 4th to 3rd gear and 4000 rpm's up, like when passing other cars for example, I see some blue/gray smoke by the rear view mirror. Is it because of valve seals or could it be piston rings wear? How to know?
My oil consumption is about 1qt every 2K miles.
Thanks guys and girls.
My oil consumption is about 1qt every 2K miles.
Thanks guys and girls.
Super Member
Joined: Sep 2002
Posts: 625
Likes: 6
Have you recently changed to synthetic oil? Not always a good idea on an older engine. The oil "useage" you see is consistent with the 103 engine and most of that is actually thrown out the front of the engine and not consumed. Have a compression test done and take it from there. Good luck.
MBWorld Fanatic!
Joined: Aug 2002
Posts: 1,005
Likes: 33
From: Germany
'00 S320 W220, '98 A160 W168/ sold in 2005 '86 260 E W124 '90 260E W124
Hi Rafael,
blue/grey smoke is always burnt oil. A consuption of 1 quart per 2 kmls is no alarm sign. It most probalby is the combination of stem seals and normal oil ring wear. If the valve stem seals are really bad, you'll also see greasy/oily spark plugs, and the comsumption rises above an acceptable amount. Anything less than 1 quart per 0.8 to 1k mls is still ok. Even MB says 1 liter per 1000 kilometer is within acceptance.
blue/grey smoke is always burnt oil. A consuption of 1 quart per 2 kmls is no alarm sign. It most probalby is the combination of stem seals and normal oil ring wear. If the valve stem seals are really bad, you'll also see greasy/oily spark plugs, and the comsumption rises above an acceptable amount. Anything less than 1 quart per 0.8 to 1k mls is still ok. Even MB says 1 liter per 1000 kilometer is within acceptance.
