[iwagner]

2010 328i SULEV with N51 142k Miles. Just started having rough idle at startup, metallic noise from the front of the engine and 2A7C code.

I suspect that the vanos bolts are either loose or sheared, the vehicle is affected by the vanos recall (no remedy). I just dropped it off at the dealer to see if they'll replace the bolts under recall/warranty and I'll keep posted on what they find out.

[iwagner]

Dealer wouldn’t touch recall, basically did a courtesy check, read codes and stated engine was sludged and that was probably causing vanos codes. I’m going to seafoam the engine, do a couple quick oil changes and pull the vanos solenoids and give them a clean and see if it resolves anything.

[mct128i]

Originally Posted by iwagner

Dealer wouldn’t touch recall, basically did a courtesy check, read codes and stated engine was sludged and that was probably causing vanos codes. I’m going to seafoam the engine, do a couple quick oil changes and pull the vanos solenoids and give them a clean and see if it resolves anything.

Prior to replacing my valve cover last year (to fix a leak) I was seeing the 2A7C code and once the old cover was off, sure enough there were loose and broken VANOS bolts. I consider myself lucky to have made the discovery at that time since they were easy to replace with the cover off and I've not become aware of any damage from the loose and broken bolts since replacing them.

You might want to consider using a bore scope camera through the oil filler to see if you can check the presence and condition of the 8 bolts without having to remove the cover. You would need to remove the spark plugs to enable rotation of the camshafts via the crank pulley.

[iwagner]

Dealer just called, recall is available so going to bring it in. The code hasn’t come back since I cleaned the solenoids. I’m curious to see if I have sheared bolts.

[iwagner]

Just an update. Recall finally available, 1 sheared bolt and two loose. Dealer replace and dropped oil pan to remove missing bolt. Once the pan was removed they found a considerable amount of non-Vanos related debris. Does anyone recognize what these parts are?

[iwagner]

Also found this bolt head.

[Suvorovo]

Is that the aluminum "head bolt" sealing the timing section of the head?

I thought this was an issue on early 06 n52 models... Can you confirm that all four bolts are there? There's one by the OFHG and 3 more below vanos sprockets. I paid a shop to drill them out and replace them after I found all four sheared off during valve cover job. I'm definitely one of a very few people who fixed this, it's probably fine to leave them as is.

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[iwagner]

I think it might be a head bolt, car is running fine right now with no oil leaks. Original 2A7C code and rough idle are gone. I’m going to leave it as is until I get an oil leak then pull it apart and replace the bolts. Thanks for the confirmation!