Smoking WVO

Help! My 1985 MB 300D which has a coolant heated wvo system is smoking. Mostly on acceleration. The rear tank, which is where I mistakenly put the thermostat, reads 120F so I'm pretty sure I'm getting up to 150-160F up front. I've been checking the engine oil and it doesn't seem to be burning oil. Does anyone have any ideas why it might be smoking?

Reply to this post

Enter the characters shown in the image.