I'm afraid I already know the answer....

Overhauled my 3.0 litre OM603 20k miles ago. It was assembled with a fairly new #22 head, new head bolts and a Reinz head gasket. It's been great for the last 20k miles, until yesterday....

While idling, (engine thoroughly hot, 85c) I noticed for the first time, white smoke- and a fair amount too. Cleared up while driving, seemed to come and go, engine running smooth and quiet.

Later in the day, I noticed the engine temp start to run a bit warmer, switched on the heater and headed home. Checked the coolant tank, and it is clearly low.

I haven't touched anything since, , too depressed.

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Chief

1991 350SD