Coolant loss - exhaust

[Variante Alta]

Hey everyone. I have a 2015 F15 35d with 160k miles. I am losing coolant through the exhaust quite quickly at times (great plumes of coolant vapour). There are no external leaks (I park in the garage every night so would see it for sure and have had many of the underbody panels off). The upper EGR cooler has been replaced twice by BMW (the most recent one about 18 months ago) but it should be turned off in any case through the delete tune.

I have not noticed any loss of power or performance (head gasket) and the turbo seems to be good as well although I recently got a code in ISTA (Code 2 BBC00 - Charging pressure actuator: mechanically faulty near open position). This fault was cleared and has not come back over a couple weeks. Interestingly, among the reported conditions at the time of the fault was the ‘Actual position of exhaust gas recirculation valve’ showing 35.4%. Hmmm…thought the tune should have this at 0% but not sure on that.

I’m suspecting the lower EGR (on the passenger side of the engine) but there do not appear to be any codes saying it’s malfunctioning (it’s possible there would not be with these?). The turbo is cooled within the coolant circuit - could it be leaking internally?

Any diesel heads with similar experience care to chime in with their thoughts? Many thanks.

[Variante Alta]

As an update, the car was looked at and based on leakage around the exhaust cooler, it appears to be the culprit. It is the cooler on the exhaust manifold side of the engine, not the EGR at the front which has been the subject of numerous recalls. Will report back once the replacement is in and tested.

[m4forum]

I had coolant leakage on EGR cooler next to exhaust early this year. Unfortunately it also fail like the EGR cooler in front of the engine.
it isnt hard to replace ... can remove and inspect ... visual inspection can confirm the issue.

[m4forum]

pictures

[Variante Alta]

Hey, thanks for the info. I’ve considered removing it myself to replace it (new cooler will be here Monday). I’m pretty handy and have the ISTA instructions but am a little concerned about getting the bolts out without breaking them considering the heat from the manifold. Did you do anything in particular when removing the cooler bolts? I live in fear of snapping one off

[m4forum]

was very easy. didnt have any issues.

[Variante Alta]

Okay, good to hear - many thanks. Will report back once I’m done.

[LateParty2018X535d]

FYI - I have both EGRs for sale if anyone interested. Getting ready to put on Ebay after deleting. All in good working condition prior to removal. BMW did recall repair already. 2018 model approx 62k miles on them. Selling for about 20 to 30% off internet price TBD. Have photos and documentation. If interested let me know. Have a quality DPF and Cat also!

[objective-poet6757]

I have a 2018 X5 diesel and have been having similar issues--constant low coolant with no leaks detected after probably a dozen pressure tests.

EGR valve was replaced in April, then the main EGR 2 weeks later and then replaced again in June. X5 has been running worse since and coolant issues are worse.

No loss of power, at start, you can feel a shake probably 1 in every 3 starts and white smoke out of the exhaust.

Dealer says main EGR is fine, could be the rear EGR (my mechanic suspects this is the issue). Dealer also identified an EGR sensor temperature fault.

Did replacing the rear EGR solve your problem?

[Variante Alta]

Hey - for me, removing the cooler (sometimes referred to as the 'rear EGR' solved the problem. It was leaking internally and leading to the coolant loss and white smoke.

Sadly for some reason BMW never covered the coolers on our cars.