[MooLard]

Hi there

Has anyone had to replace this part before? It is a pipe that runs from the auto gearbox to an oil to water heat exchanger. It is weeping at the heat exchanger end, my car has just hit 100k miles so I guess it's stood up quite well. It is part number two on this diagram.

http://www.realoem.com/bmw/enUS/show...diagId=17_0315

Any feedback on doing this job would be well appreciated, thanks in advance.

[335dlci]

I have done one but on a gas verison
Ypu have to drop the subframe usually

[MooLard]

I have been monitoring this since it was done and the heat exchanger appears to be leaking coolant. Where can it be leaking from? I am finding it hard to understand from the realoem diagrams. I believe there is an o-ring or two on each coolant pipe, but what does the heat exchanger join to and how, is there a gasket there?
Has anyone done this job? Any pointers would be well appreciated.

[BourneJack]

Originally Posted by 335dlci

I have done one but on a gas verison
Ypu have to drop the subframe usually

[Asonchadwick]

I would unscrew the cooler from the fan shroud all the lines are quick disconnect just disconnect them and replace the cooler if it's leaking I would also check all the O-rings inside the plastic quick disconnect fittings could be one of those is bad maybe it's a hose as long as the two aren't mixing coolant and it's just leaking antifreeze externally that's okay but if they mix oil and transmission oil think you're going to have a real problem these things usually don't go bad but they do have a thermostat inside not sure if that would have anything to do with leaking externally. I think replacing the lines is relatively easy from what I've seen under the car unbolt the line at the transmission in both of them will have to be at bolted at the same time it's a clamp that holds them in and then just separate the two lines down the car and just use the quick disconnect you shouldn't have to drop any subframe or anyting.

[MooLard]

Brilliant thank you for the detailed reply that's very helpful. So at the least I can replace two coolant pipe o rings, or replace the oil pipe o rings too while I'm here, or replace the whole cooler.
I've had a stack of bills lately so I think I'll do the coolant o rings and coolant refresh for now.

[Asonchadwick]

Let us know what happens and what you run into!

[Bimmer_Engineer]

Originally Posted by MooLard

Brilliant thank you for the detailed reply that's very helpful. So at the least I can replace two coolant pipe o rings, or replace the oil pipe o rings too while I'm here, or replace the whole cooler.
I've had a stack of bills lately so I think I'll do the coolant o rings and coolant refresh for now.

Any updates on this? I was changing my serpentine belt today and when I moved the trans cooler out of the way and it started dripping coolant. I pulled the Connection that was leaking and it doesn’t have an o ring...it’s not cracked...so I put it back on. I was pissed enough at the car today to not do a coolant bleed cycle to see if it’s still leaking...

[streetpro]

if it drips AT oil you need to change these o-rings (there are 2 black inside of each quick-connectors), one solution is to change it to the "an" standard and replace the hose from the steel line (or use the push-on connector to joint the rubber hose).
However I am not sure it is an6 or an8 size...
any ideas?

https://www.aliexpress.com/item/3288...chweb201603_53