BMW E81. 16 year old plastic radiator connectors.

[Derry Rhumba]

Morning all.

Yesterday afternooon, popped the front undertray off Mrs DR's 2010 118D (e81) with the intention of flushing out old coolant and replacing with new. This was the final bit of autumn servicing following changing all other fluids as well as a new crank pulley, belt, tensioners. I left this to last as I though it would be a quick, straightforward job, like I'd just done on my petrol E90

It was a bit of a faff really as the numerous 8mm bolts were nearly all rusted; so I was a bit pissed off to find once the tray was off there was no radiator drain plug obvious.

A delve into google advised me that on diesel E81, the intercooler sits below the drain plug and has to be removed to access it; also seemed to say removing the intercooler involved taking the front bumper off.

So an alternative obviously is to remove the lower hose, BUT the internet also states it is "highly likely" the crazy BMW plastic connectors will break during the hose removal. Several people on forums have said a bit of gentle heat mitigates this risk, and it is doable with carefull back and forward motion

So; anyone done this recently....can't really afford to put the car out of action if I break a connector, but I'm wondering if the net is overstating the risk here?

[E-bmw]

Never bothered with heat, but have found a bit of soapy water & some gentle wiggling normally gets them moving, just whatever you do, don't "go nuclear" unless you have a plan B.

[Derry Rhumba]

E-bmw said:

Never bothered with heat, but have found a bit of soapy water & some gentle wiggling normally gets them moving, just whatever you do, don't "go nuclear" unless you have a plan B.

Thanks for the help; used a wee bit of lube, and tried some heat also, no joy. I could have yanked harder but I really didn't want to push it; if it was my own car, maybe. (Of course my car has an accessible petcock.

Looked at taking the intercooler out; the 2 bolts looked completely done in; possibly not reusable, so a different way of getting stuck!

Pretty frustrating as I can't remember the last time I aborted something like this.

[C-J]

Have you tried when the engine/coolant is hot?Or pouring some boiling water on the hose end - to make it more supple?

[Derry Rhumba]

C-J said:

Have you tried when the engine/coolant is hot?
Or pouring some boiling water on the hose end - to make it more supple?

Thanks for the reply

Hot water and also a heat gun, along with lubrication.

These BMW so called "quick connect" coolant hoses are a bit of a pain.....unlike a rubber hose, heat doesn't really make either end more "supple", unlike a rubber hose onto metal. Plastic pushed onto plastic and probably crusted on. Got away with it on previous (petrol) BMWs as the drain plug isn't covered like the E81 diesels. Also, first time dealing with these so no real reference point on how hard you can tug (!), but I could see the plastic at the radiator wanting to give.

I think if I had pulled any harder I would have had a breakage, so undertray back on, car back in use, collant change can wait till I've had a think about it.