Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: michael on December 31, 2007, 08:07:46

Title: Smoke from exhaust if accelerate hard over 80mph
Post by: michael on December 31, 2007, 08:07:46

Hi,

excuse what may be a simplistic question but an utter novice here!

I have a 1968 280 sl automatic, when I accelerate hard over 80mph the exhaust emits lots of smoke. If I accelerate up to 80mph nothing, I know it may mean the engine is burning oil but why only after 80 mph?
It did it for the first time yesterday after I had put about 8 litres of oil in, could that be the reason that I put to much oil in or could it be because I used the 'kick down' pedal above the accelerator for the first time?
any feedback would be gratefully appreciated.
thanks and Happy New Year to all members

Title: Re: Smoke from exhaust if accelerate hard over 80mph
Post by: Paddy_Crow on December 31, 2007, 08:43:33

What kind of oil did you use? If you changed to a thinner oil, it could have an effect.

It is normal for an engine to consume more oil at higher speed and load. It may be excessive if it smokes, though. I probably wouldn't worry about it if it only does it under that specific set of operating conditions. Think about how often you execute that maneuver.

The trick is determining where it's coming from. The three most likely paths are valve stem seals, piston ring to bore interface, and crankcase breather system. As your valve stem seals, piston rings, and bore hone pattern wear the amount of oil that gets past them will increase. Blowby also goes up, which drives more carryover into the breather.

Democracy is two wolves and a lamb voting on what to have for lunch...

Title: Re: Smoke from exhaust if accelerate hard over 80mph
Post by: Naj ✝︎ on December 31, 2007, 08:57:21

8 Litres may be too much oil....
I believe the capacity with filter change is 6.5 litres...

naj

68 280SL

Title: Re: Smoke from exhaust if accelerate hard over 80mph
Post by: ja17 on December 31, 2007, 11:55:10

Hello Michael,

Too much oil is not good for the engine. The crankshaft will whip the oil into a froath then you will be circulating "oil foam" through the engine instead of a good oil stream. Drain some out before you take it out again.

Joe Alexander
Blacklick, Ohio

Title: Re: Smoke from exhaust if accelerate hard over 80mph
Post by: glennard on December 31, 2007, 12:13:46

8 litres!  What did 'dipstick' say?

Title: Re: Smoke from exhaust if accelerate hard over 80mph
Post by: Paddy_Crow on December 31, 2007, 15:40:20

According to the tech data booklet, 8 liters is about 2-3 liters too much.

Democracy is two wolves and a lamb voting on what to have for lunch...