Om603 stalling and dying, plus smoke - PeachParts Mercedes-Benz Forum

w123fanman · #1 03-25-2020, 10:44 PM

We put an early 603 with at least 280k miles into our 300D 2.5 when we discovered the 602 turbo needed new valve seats. It has a #14 head and ran great. It has not gotten hot since we put it in, but a failed head gasket or head is always a possibility here.

The symptoms are whitish smoke (doesn't smell like coolant) and the engine will stall. These issues may not be related, pretty sure the turbo is leaking and needs to be rebuilt so that might be the smoke. The car ran great on the hour drive this morning to our shop but after sitting for a few hours, went to drive it and it would randomly lose power and stalled out a couple of times. Other times, the turbo would spool fine.

I can watch the stop lever on the IP fall as it stalls so thinking it may be the idle control acting up. I will try unplugging the solenoid tomorrow to see if that changes anything but if anyone has any ideas as to what could be happening, I'd love the input. Also, if anyone knows where to get a rebuilt turbo, that would be great.

dieselbenz1 · #2 03-26-2020, 03:10 AM

Air is getting into your fuel.

Diseasel300 · #3 03-26-2020, 10:00 AM

The stop lever is spring loaded. If no vacuum is supplied to the shutoff valve, it should be sitting nearly straight up and feel like it's on a spring.

The shutoff valve is installed incorrectly so it is not engaged with the lever, The "Stop" lever is installed incorrectly, or the vacuum switch in the ignition is leaking and causing the engine to stop.

Yes, a floppy stop lever will cause this type of behavior.

w123fanman · #4 03-26-2020, 03:29 PM

Turns out the PCV system was clogged

Diseasel300 · #5 03-26-2020, 03:49 PM

That'll sure do it too!