2002 BMW X5 3.0i coolant in engine oil, and engine oil in coolant

[upallnight]

You can get a kit at Pep Girl, Manualzone or O'Malley that can test for compustion gases in the radiator to verified that the headgasket is blown. Right now you are just assuming a lot of things and until you know for sure I wouldn't be removing the head. Stay away from the cheap miracle fixes, they only cause more problem down the line.

https://www.youtube.com/watch?v=U0DdVQoBu4U

[g300d]

Yup...mayo on oil cap could be the crankcase ventilation system, but the overheating would be something separate.

Trans heat exchanger failure would give you trans oil in coolant and possible low coolant levels if the coolant were migrating to the tranny, but would not affect engine oil.

I agree with upallnight, do check thoroughly...I almost pulled the head also when I saw mayo in my coolant reservoir, pressure testing the trans oil cooler was just part of ruling everything out, thankfully it turned out to be the problem after all.

[beamer9]

I've got a new clue, that may or may not be related. The high pitched whirring sound that is associated with the oil separate has been happening for about 4 months. It seems to only make the sound at idle. I thought it was related to the steering but realize now it might be related... That said the yellow oil looking stuff appears to be coming out of the water hose from when it overheated... I'd say it's definitely not water condensation, however, the car has been smoking white smoke, and the nasty burning oil smell has been coming from the engine randomly for some time now. I assumed it was a common oil leak. The oil mixed with water is new. Is it possible for the oil separator to mix oil and antifreeze together?

[upallnight]

Originally Posted by beamer9

I've got a new clue, that may or may not be related. The high pitched whirring sound that is associated with the oil separate has been happening for about 4 months. It seems to only make the sound at idle. I thought it was related to the steering but realize now it might be related... That said the yellow oil looking stuff appears to be coming out of the water hose from when it overheated... I'd say it's definitely not water condensation, however, the car has been smoking white smoke, and the nasty burning oil smell has been coming from the engine randomly for some time now. I assumed it was a common oil leak. The oil mixed with water is new. Is it possible for the oil separator to mix oil and antifreeze together?

Only if the head gasket is blown and you have anti-freeze in the crankcase.

Perform the following test. Start the engine and let it warm up. With the engine still running remove the oil cap. Is there a large vacuum present?

[beamer9]

Started car, and removed cap while whirring sound was on and it didn't get quieter. Checked the dip stick and Coolant is definitely in the engine block, it appears to be somewhat recent though. The oil is overflowing, I assume from water in the engine oil. It's clearly watery substance, but has not yet run enough to turn internals different color. I felt no vacuum in the engine, with the cap off instead I noticed water vapor coming up.

[upallnight]

If you remember you high school science you will recall that Oil float on top of water. The oil pick is normally at the bottom of the oil pan, so it is sucking up water instead of oil. I would not be running the engine until you have at least removed the water from the sump or else you are liable to burn a rod or crank bearing since water has nowhere near the same properties as oil when it comes to lubrication.

[beamer9]

I tried the gas test on the cooling system and its not turning yellow, although some oil chunks of what I assume oil got in a couple times and turned the water bluish green... I am going to flush the system. It seems more water is going in to engine than oil into radiator.vvery little.

[beamer9]

I made a decision. I am going to flush the Coolant, run bars hd1 head gasket & coolant seal repair, then I am going to flush the oil, and see what comes of it. I am comfortable with my decision if it buys me a more time during holiday season. One factor in my decision is the Coolant has very little oil, and it seems to be pouring into the engine oil. If it doesn't work I may need to do more work to fix it. I'm trying it because I am reminded of an epoxy seal I used for rethreading a spark plug, and it lasted through multiple head valve jobs, and replacements. I'll keep you all posted on what happens...

[JCL]

I would be using a cooling system pressure tester with a manual pump, and see what shows up.

[beamer9]

Was the first thing I did with advice from upallnight. Thank you for your help