11-23-2012, 09:02 PM
Officially Welcomed to the 'Fest
Location: British Columbia, Canada
Join Date: Feb 2008
Mein Auto: 2004 X3 2.5i
1. AFAIK, the expansion tank mates into a plastic mount that is attached to the radiator.
Originally Posted by silentbob
When I pulled up and popped out the coolant expansion tank, I discovered that a part on the base where the expansion tank plugs into on the bottom was broken ................
something that is directly attached to the radiator, or some other intermediate coupling piece?
Also, I had trouble getting to the engine block drain bolt. I have genuine BMW coolant ready to go, but the old stuff was orange colored. Am I asking for trouble by topping it up with the BMW stuff?
The tanks don't normally pop out, and generally are quite difficult to separate from the mount.
There are a few reports on the E46 boards of that costly ($163) plastic mount breaking if you pull too hard at an angle.
(Those who approach it from below and use a jack and suitable drift like a fat dowel seems to have an easier time. Or just levering carefully at the base with a small pry bar.)
The A/T thermostat is quite fragile by nature, and either is ready to be replaced by the time a tank has cracked, or gets broken during removal.
So if it's just that you didn't screw up too much.
Some people handle things by uncoupling the plastic mount from the radiator (slide fit?) along with the tank and separating them on the bench.
That might help to preserve the A/T thermostat if desired and also make pressing the new tank in much easier.
2. The drain bolt on the block is reportedly somewhat hard to access with the exhaust manifold or heat shields being in the way. It's just a plain bolt so not too obvious.
Containing the flow once the bolt is removed is another challenge.
Maybe try ramming a piece of tubing in the hole quickly?
Orange coolant is a bit unsettling.
Maybe it's the Chrysler version of Glysantin G-05 (see attach.) which wouldn't be too bad as Zerex G-05 is quite similar to BMW G-48 stuff, just having a higher touch of silicates (310 ppm vs. 250 ppm).
But you don't really want 2 different colors mixing in there and I think the only way to get it all out of the heater core is with a professional flushing machine.
Repeated fills and drains of water with runs up to operating temp. is the only DIY hope.