Hey all, in the midst of restoring 87 528e. If I pull 4K in 3rd or 2nd gear I get a distinct metallic smell from the engine bay. Not sure what this is, or how much I should be concerned. I will note that supposedly the limiter was removed but I have not investigated the ecu yet, which is why I am cautious to go too far into the 4K rpm range. Maybe this could be head damage, any thoughts?

Ben

1987 BMW 528e 5 speed