Purchased a new coolant expansion / header tank to replace the original 1988 part from the donor car. For the first time since building the car you can see the coolant level! Should have replaced this years ago, but it’s not the cheapest part to get new. The nice thing is you can still get new original ones. They were use on the E30 and on the Z3.
Added a new blank cap to replace the level sensor cap with a fresh o-ring as well.
Needed little bit of modification for the lower mount – a hole drill into it.
The old one is almost solid, the lower hose connection was coming to bits too, the metal insert on its way out the end.
Looks a lot nicer with the new tank.
You can really see the opacity difference.
Nice clear fill level:
Engine bay looks much cleaner now.