Originally Posted by mistryn
I am going to attemto to do mine on my 335D this weekend so will post on here how it goes. The only thing I am slightly nervous is getting the EGR exchanger off with the various bolts.
I plan on siphoning as much coolant out of the expansion tank before I start to undo anything to minimise spillage. I also plan to leave the under tray in place and if any coolant does leak it will drain out?
Another thing I am slightly wary about is bleeding the system, do I add coolant neat and then water on top or do I mix coolant and water (50:50) in a container and then pour?
EGR HX it is just a bit of a fiddle, just be careful you don't drop parts.
I syphoned my coolant from expansion tank and small hose under the EGR HX... only lost about a mug full.
My coolant bleeding method, once the bulk of the coolant is back in the expansion tank, switch on, push start button without brake, to get climate control active/valves open, but no engine. Then squeeze top hose a bit, some air will bubble out. Fit the pressure cap and squeeze the top hose gently
until you get coolant to the top of the EGR 'stat bleed point, screw in bleed screw, while hose is held and coolant is visible/solid.
Then I removed the pressure cap, topped the coolant level and started the engine. Virtually no air and required less than half a litre to top again. Screwed on pressure cap and I ran the engine for a few minutes, proved no leaks as pressure built up... and then went on a test drive.