Try posting on the diesel forum, next one down the list from the tech forum, you may get some better answers there. How many miles on the engine?

I am not an expert but...........

Now that you are adding water, where is it going/leaking. Water pump failure?

What temp was the engine at when you started seeing the steam? Did you go to red on the temp guage?

Low power can be an indication of low/no fuel delivery. All filters checked and OK?

The injection pump was not designed to run veg oil, (flame suit on) hope that is not your problem, because it could get expensive. Have you tried running on diesel? If you overheated it badly the IP might be the least of your worries.

Good luck!

Clay

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2002 E320 Sedan 93K Designo Mocha Black Metallic!
1995 E320 Wagon 205K Black Wagon
1982 240D 183K SloPoke

I believe each of these cars are the final production year for that model.