cold start and restart issues

[hands_aus]

At first start up car was running rough.
Pumped the accelerator pedal couple of times, it settled down to normal cold engine idle.
Went out and on way home had to use mobile. Stopped car and switched off engine.
Car didn't want to run properly and stopped.
Lifted bonnet and had a look, nothing visible.
Tried starting again and observed fluid moving in clear distributor vacuum line (Venturi end). No fluid distributor end.
Thought that was definitely unusual.
Separated clear vacuum line from black plastic tube that connects to venturi port.
Fluid seemed to drain into inlet manifold.
Reconnected lines and tried starting engine.......fired right up smooth as usual.
Arrived home with no problems.
Checked oil bath air filter and connencting hose .... all clear
Checked inlet manifold.......all clean, no sludge.
Not sure what the fluid was but it interferred with vacuum operation of distributor.
Went for test drive today, no further problems.
My understanding is that the 250sl inlet manifold vacuum point is on the bottom of the venturi unit which probably allowed some oil bath filter oil to pool and run into the vacuum line.

Anybody had similar situation? Thanks

[66andBlue]

Bob,
I can't help you much but awhile back I had also noticed some fluid in the vacuum line; the "bubbles" would move towards the Venturi when the engine was running.
Joe A. suggested that I check for a leak in the diaphragm on the distributor since engine oil could have been sucked in that way. Disconnected the Venturi tubing and pulled some vacuum (with engine off) and checked for a leak but found nothing, vacuum remained stable for about an hour.
I still don't know from which end, and how and why oil had entered the tubing but since then it has not reappeared.

[hands_aus]

Hey Alfred,

The engine is running normally again, so I will monitor the vacuum line more closely for a while.

Thanks for the reply.

[bpossel]

Here is some information that I found in my archives of 113 info that I have collected, it may help....

"...If you keep your car in a garage and take it out on a sub-freezing day, the icing up can occur while the car is being driven—not good! The 280SE/SL pump is much more prone to this, due to the fact that it is lubricated from the engine; the ice forms from water vapor that is produced in the crankcase and ands its way into the pump. Cleaning the rack mechanism may not solve this problem—you need to attack the conditions that cause formation of water vapor in the crankcase (e.g., bad head gasket, poor crankcase ventilation). If all else fails, installing a small breather in the pump side plate might help; however, not sure how much if any oil might leak out through such a breather.

The throttle icing condition is also related to crankcase water vapor; however, unlike the pump icing condition, it occurs only on early cars. All the cars of this series have a crankcase ventilation tube going from the valve cover to the throttle housing. Even in an engine in good condition, this tube carries a substantial amount of water vapor in addition to other blow-by products. The venturi effect in the throttle housing in combination with low ambient temperature can cause this water vapor to deposit on the throttle plate in the form of ice, causing the throttle to stick in the part-open position—again, not good! The vent line itself can also freeze up and lack of ventilation will cause crankcase pressure to build up to the point that oil is forced out of the engine through the tachometer fitting and other seals. A largely unsuccessful attempt was made to prevent such freezing by adding a warming loop to the front of throttle housings. An effusive solution depended on redesign of the throttle housing to include a warming water circuit, plus warming the vent line by providing a rubber cuff surrounding it and the hot water line to the throttle housing; this design became effective in the 280SE/SL. Earlier cars can be retrofitted with the water-warmed throttle housing and necessary piping; but if you want to keep your car original and still want to drive safely in cold weather, the only solution is to disconnect the crankcase vent line at the throttle housing..."