Hi guys, wondering if anyone knows how to take off these coolant hoses going to the heat exchanger behind the engine, mine is chocka full with peanut butter. Or anyone have any idea how to clean this? Put a new heat exchanger in and flushed coolant, no oil or signs of oil so assuming the blockage is only on the steel lines?

 

https://www.realoem.com/bmw/enUS/sho...diagId=17_0237
Diagram at link above indicates it's one assembly held on with two bolts, connected as shown at one end to the oil cooler and the rest of the heater / cooling hose network at the other. If your bolts are badly corroded / frozen would consider leaving it in place (assuming the pipes are not leaking) and gently flushing it from both ends and using a long bottle brush to clean out the peanut butter as you say. Failing that, replacement:

https://www.outmotoring.com/_search....03&categoryid=

 

Hey, any idea how to access the bolt for it? I cant seem to reach the one near the thermostat side? Do u get at it from the top or bottom?

 

Would go through the right wheel well for that end and probably from above after removing the air box and ECU (remember to disconnect the negative battery cable first) and possibly from below, not sure.

 

You are talking about the cooling loop? The bolt is from the top. 10mm iirc.

or just unhook form heat exchanger, put some simpl3 green in it and hook a hose up to it and flush it?

 

two bolts from the top, long way down, under the heat shields. Still have to come in from the left side to disconnect those hoses and R/R it. Would think flushing would best be accomplished with left side ends open anyway but maybe not. But if you're at that point, might as well just remove it altogether before cleaning / replacement. Then 'while you're in there' R/R the thermostat, housing, temperature sensor, and Rube Goldberg labrynth of 22 tiny coolant / heater hoses, plastic connectors, and skin-shredding factory clamps stuffed in behind the engine...it never ends...