smoke screen

[gf]

Ive had my w116 for a few months now which until recently sat in a shed for a decade. Has well under 200 000km on it. On hard acceleration  from zero the car leaves behind a white smoke screen, used to be of uncle buck magnitude! but is less now. My friend says its cause the piston rings are sticking from disuse and will get better with time. Any thoughts on this? should i just drive it hard for a while to make them work again?

[s class]

If the smoke is indeed white, it could be ATF, if the modulator valve has failed.  Keep an eye on the transmission fluid level to see if its dropping .

[gf]

thanks man! ill check the transmission fluid.

[Kris P.]

I have the same problem with yours actually.  Everytime I use my car, it seems that everything's ok but if I leave my car for 3 to 5 mins idling, a hint of smoke (white and bluish)  is seen.  If I rev the car it would smoke and then it will go away then.  After that everything is fine again until I idle again.  Where could i see that modulator valve? are there any problems that could cause this?

[oscar]

Kris, I reckon your problem's more to do with worn valve stem seals.  Warm your car up, go for a drive and whilst your doing about 50km/hr whack your transmission into S or L and take your foot off the accelerator.  Make the engine slow your car down.  You might notice a bit of smoke develop.  The longer you let the engine do the braking the more there'll be.  Accelerate away and it will smoke a bit before it clears.  What's happening is that at idle, the engine genrates a high vacuum compared to when the throttle is opened.   The vacuum created as the pistons move downwards suck oil in past the valve stem seals, even more so when the throttle is closed and the engine is forced to rev during engine braking.

FWIW the modulator is on the RHS of the transmission just above and behind the AT fluid pan.