n54 coolant in oil

[Declanmorg]

I recently bought a 2009 135i n54 and unfortunately got too exited and didn't check it out well enough before purchasing. a little bit after owning the car i got a low ccolant and low oil warning and i checked my coolant and it was mixed with oil, i then checked my oil cap and it had some creamy oil coolant mixture on it. i did some research and most things lead back to the OFHG so i replaced that and the oil cooler gasket as well as flushed my cooling system a few times and an oil change. I drove the car for about a week or 2 after that and everything seemed to be fixed until the other day i started my car and got a low coolant warning, i checked and my coolant tank was almost empty and the residue was back on the oil cap, i filled my coolant back up and drove around for a while and then inspected again and it doesnt seem like theres any oil in the coolant but there was quite a fair ammount of mayo on my oil cap. My car is bone stock other than intakes. Anyone have any ideas on what it could be?

[zx10guy]

Might be a head gasket. You can do a simple check by using one of these testers that reacts to combustion gases that leak into the cooling system:

https://www.ebay.com/itm/11360298927...1089_377870104

[ejm3]

Sounds like head gasket to me.