Thanks to all who provided inputs during my head gasket replacement job on the OM603. The engine runs perfectly, and is much quieter than before, having planed a warped exhaust manifold. Also, no more oil in the coolant (so far). The 150-amp alternator is also a nice improvement--thanks to GSXR for the idea. And the glow plug light works correctly! New plugs fixed that.

However, it now takes at least a second to shut down, whereas it was immediate before. A new leak? Sluggish switch? What could have changed?

I've also noticed that the transmission shifts more smoothly with the ventilation system shut off. Pulling the dash looks like the next big job. Suspect at least a couple of leaky pods.

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Rob

Vacuum for engine shutoff is sourced from the check valve along the brake booster hose. If you can do so without damaging brittle plastic bits, run a hose directly from the check valve nipple to the shutoff actuator and see if takes time for the engine to shut off. If so, the actuator is likely starting to go. If the engine shuts off immediately, you're likely developing a leak between the check valve and the actuator. It's a fairly simple routing - brown line to the key switch, brown line with red stripe to the actuator. It doesn't help that most of that stuff in tucked away in the dash and other hard to access locations. Use a MityVac on the hose that attaches to the check valve. With they key in OFF, see if the system holds a vacuum. 20"Hg is good, below 15"Hg is probably unhealthy.

The shutoff lever in my car stays down for days. Maybe weeks. Does your stay down that long? I realize this last statement opens the door to the comedians on the forum

Sixto
87 300D

There was a small hole in the rubber hose joining the line from the actuator, where it connects to the brake booster hose. Not really a split--just a hole. Cut off the end of the hose, and everything is well. Thanks!

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Rob