Automatic engine shutdown when exiting the freeway!?
 

We drove the W115 240D to Santa Monica today and being late I was pushing the car nearly to the max at 78mph :eek: I exited the freeway in 4th gear and then approaching the stoplight I depressed the clutch and then I saw the engine spool down, the oil pressure dropped and then the engine shut off! I rolled the car past the intersection to the right and then switched on the hazards. I cranked the engine and off we went as there was no shoulder. We made it to the pier and checked the oil level which was about 1/3 from the low mark. Has this happened to anyone before? :eek:

Does the engine shutoff normally (eg key off)?

It's a W115....manual fuel cutoff with the pull-push knob. ;)

Curtis,

Did you check the oil level before going? It may have been low since yesterday's drive was quite far. That 5qts of Castrol oil was probably worth it!

I didn't because we were in a hurry to leave but it was fine when it all settled down after it cooled.

The same thing happened to me one time.

The W123 had just had it's IP timing adjusted at the mechanic. It was low on fuel.

Exited the freeway and it stalled on the ramp. Restarted immediately and never repeated the symptom. Mechanic had no idea why............???

ummm not neccesary right? i have a 115 300d, and its cut off by key, no manuel cutoff, u r saying it is because it is a 240d right, i though the 300d's were key cuf off (like mine)

I have both cars and the 240D doesn't have all the luxuries of a single key operation like the 300D.. It has a pull knob with no glow timer or key operated starter operation. The key just unlocks the steering wheel and turns on the few electronics it has.

Air getting in the fuel supply somewhere will cause this senario on other brands. Worse case I had was constant quitting on sharp left turns. Turned out to be a crack in the water separator at the back end. Found the dry crack and thought no way this is the cause. As so far removed from the engine. But after I changed it out problem stopped and it was constant. Strange thing was as soon as it quit it would restart and run normally until you made another sharp left hand turn. If it does not do it again I would not worry about it. But if it becomes more prevelent suspect the fuel system. Also make sure you tank vent line is pretty clear. When you slowed down the fuel pump or lift pump may have stopped pulling so hard and the reduced ability to draw fuel from a poorly vented tank killed it. May only have taken a few seconds for just enough air to enter the fuel tank to enable the restart. Just something to consider as basically it sounds like you ran out of fuel or quantity was too small to keep running.

:eek: even the later models 240's were like that? why didnt they upgrade that to a key starter when they updated the chassis? 115 > 123

The W123 240D controls everything with the key, just like the 300D.

Barry, I checked the fuel system and there was a tiny bubble that moved into the primary filter when I used the manual primer pump today. I think something had to do with the WVO mix I am using. I had 60% of a full tank at the time but as aforementioned, I was going far faster than I drive the car regularly without problems.

How can I check the fuel strainer in the tank being this is a W115? Is there a way to inspect it without pulling it or buying a $1000 fiber optic borescope?

A small bubble in the pre-filter is normal, refer to the photo of mine in post #14. The engine is not running in the photo, but the bubble is similar all the time:

http://www.peachparts.com/shopforum/showthread.php?t=164940

I suspect all your filters including the one in the tank are fine. You were almost able to maintain 80 mph for an hour. Engine quite only when you reduced speed drastically basicaly. Easiest test I can think of is to listen when you remove fuel cap after driving awhile. If tank is under quite a bit of vaccum you should hear it. Again the only variable I can think of is the ability of the lift pump to pull fuel might have been reduced when revolutions dropped on 123s and perhaps on 115s as well. Partially obstructed and totally obstructed tank vent lines are fairly common. The other thing that will shut these engines down is excess blowby. The crankcase pressure shuts the injection pump off. If engine was quitting at speed a guy might want to make sure his engine vent or pvc line was clear. But you ran fine at speed and I cannot see suddenly developing excess crankcase pressure when you slowed. The ability to restart pretty quick also leads in the first discussions direction.

oh ok, from diametricalbenz sig, i assumed he was talking about both 240's and i assumed the 79 would be a 123, and it was hard to belive that all the advancements that chassis had, they would leave in an outdated method to start it