[people_e90]

Hi, I've frequented this site for many years, but this is my first time posting in E90POST. I know many E90POST members are experienced, and I would appreciate your insight and help.

I have a 2009 BMW 328i, automatic, 4-door sedan. I have not added any aftermarket configuration.

4 years of slow coolant leak
My e90 used to leak coolant slowly. Whenever the low coolant warning sign lit up on my dashboard, I would fill the coolant tank with blue BMW coolant 50/50. I would replace the coolant every 6 months or so for about 4 years. I had no problems with AC or heater at this point.

Coolant started leaking fast 4 months ago
But about 4 months ago, the coolant started emptying fast. I had to refill every 3-4 days. I temporarily resolved the issue using the K-seal coolant leak repair.

Heater no longer works
Unfortunately, I started facing more significant problems:

1. Heater stopped working, and it's like 29 degrees outside Fareinheight.
2. I smell what I suspect a coolant burning smell only when I turn on the heater. The smell goes away after 5 minutes of turning on the heater (or maybe my body becomes accustomed to the smell).
3. Service engine soon light came up, then it disappeared. I don't see any fault code in ODB II.

Water pump appears to be working
I read on this forum that a water pump could be the issue. So, I checked the water pump condition by bleeding the coolant. If you step on acceleration for 10 seconds (roughly) while the heater runs on low at max temperature, e90 bleeds coolant electronically. I visually inspected the water pump ejecting the coolant inside the coolant tank. Therefore, the water pump functions fine.

Wet dust in front of the engine and oil filter housing gasket
Next, I suspect that there could be a problem with either the oil filter housing gasket or the head gasket.

- I see an oil leak near the oil filter housing gasket
- Front of the engine collected wet dust.

Furthermore, I also noticed that the exhaust expels white smog quite a long time only in cold temperatures. However, I do not think it's coolant smog because the smog is clear at warm temperatures.

Could I get your expertise suggestions? I'm at the border of selling this car for $1500