[jonvon65]

Hello and thank you to all who have found my post and that are willing to help me with my issue. This post may be a bit long but I'm trying to be as detailed as possible due to having already sunk so much time and money into this car that I am not considering giving up on it.

The issue is that the car will shut off randomly while driving, while idling, shortly after starting and putting into drive. There does not seem to be any particular pattern for how long the car was running for, sometimes it's immediately after starting, sometimes it would be 20-30 minutes after driving, and sometimes it could be driven for a couple months with no issue. The car has zero issues with starting, and when it is driving and idling it is buttery smooth. I have replaced many parts and sensors in this car and I have used NCSExpert to code certain parts in and INPA for diagnostics. I know this is just me being annoyed that I'm not finding the root cause of the problem, but I feel like every time the car shuts off, I run INPA and scan the DME for errors and there seems to be a different part or sensor that the diagnostics is blaming every time.

I can't remember exactly when this problem started occurring but it starting happening more often after the oil filter housing gasket ruptured, sending lots of oil into the cooling system. I had "fixed" that issue with a bunch of replacement parts and had been trying to clean out the cooling system by filling with distilled water and a cooling system cleaning formula (Liquid Moly first then Blue Devil(I think?)), driving around for a while, drain, rinse and repeat. During this cycle of removing the chocolate milk, the engine would shut off occasionally and I would try and diagnose the problem.

What I think I know about the problem is that it is electrical in nature, either a bad sensor, bad signal, a voltage drop, short to ground, etc. Mechanically the engine and drivetrain seem quite happy, like I said earlier, when it works it's buttery smooth.

Now for the list of parts I have replaced starting with the big jobs:

Oil Pan Gasket

Oil level sensor

Valve cover gasket

Valve cover (twice, first was plastic then changed to the aluminum one)

PCV Hose

Eccentric shaft position sensor

Crankshaft position sensor

Camshaft position sensor

Valvetronic motor and gasket

6 Ignition coils

6 spark plugs

Upstream O2 Sensor

Serpentine belt

Belt Tensioner

Belt Idler Pulley

Alternator (Reman)

Battery (AGM)

Water pump

Thermostat

Coolant temperature sensor

Coolant expansion tank

Radiator (this was replaced prior to the gasket rupture)

The DME (ordered used one then sent it in along with the original for a cloning service)

Intake manifold gaskets

Intake Boot

Throttle body gasket

Power steering reservoir

Auxiliary fan switch

Various cooling hoses and gaskets

Steering Wheel Lock Emulator box (from Ebay, very first part installed on car as it was the only way for me to get the car started after buying it for cheap)



I may be forgetting something but those are all the parts I can think of and the rest of the parts should have no relation to this issue. Majority of the parts are OE, OEM, or Genuine BMW ordered from FCP Euro with the exception of the ignition coils, spark plugs, O2 Sensor (all are NGK/NTK) and the alternator which was a Reman from my local O'Reillys (so no cheap junk).



I have a lot of screenshots from INPA of the different error codes that I get when I scan it and I will include a link with all the pictures attached here: E90



Thanks again to anybody who is willing to lend out some help with this issue! Two more things to note, this car is not tuned in any way and I have removed, cleaned, and swapped the VANOS solenoids but I have not replaced them.