[SOLVED] 335i / n54 / e90 Random stalling issues

I have been hunting down a stalling/stumble issue for the last few months. Here are the clues:

• Doesnt happen under acceleration
• Seems to happen less when warmed up
• Sometimes it stalls completely, sometimes the revs dip then come back up

Here are the codes that I get on occassion

• 2FDA – Crankshaft sensor, signal: missing (this one hasnt come back but im suspecting it could be my cheap ebay crank sensor)
• 0x2A99

Here are the parts that I have changed:

• Spark plugs
• Coils
• One cam sensor (I didnt realise there were two🤣)
• Crank position sensor

Here is what im doing

• Ordered an extra cam sensor and will install it when it arrives
• Going to check the PCV valve

Ill keep updating as I go! Hopefully this serves any people hitting the issue in the future.

Update – 25/10/2023 – Driving home I got the half engine light. Scanning with MHD revealed error code 2aa2 – DME: Camshaft sensor, inlet, gap loss. This was after swapping the suspect unchanged camshaft sensor to the inlet side. I have one on order. Ill see if it helps…

Update – 31/20/2023 – Received the new camshaft sensor and installed it – first impressions is that it has fixed the issue! More driving will be required to fully confirm… Stay tuned

Update – 2-11-2023 – it’s fixed! Turns out that the old cam position sensor must have been just far enough out of spec to give me issues but not consistently throw a useful code! Finally the car is feeling good again👌