Join Date: Oct 2002
Location: sf east bay ca.
Thanked 405 Times in 323 Posts
Re: FAQ on Carbon Build-Up Issue (First Attempt)
i was at dinan last week for a couple of things, and they showed me a car getting cams, they pull out the engine, remove the heads, machine some clearance etc, etc.
I asked about this carbon issue. Jeff, at dinan mountain view, told me they have had a couple of customer cars with this. He went on to say that bmw has an 'elaborate repair kit' for this problem. The main 'fix' is drilling out the passages for the smog pump, in the heads, making the passages larger. THe carbon clogs the passages that the smog pump delivers air into, i believe near/at the exhaust port. He went on to say he thought the cars they had were babied, but it sounds like that may not be the main issue, it might be a passage that was too small by design, and easily clogs.
93 M5 3.8 Sterling Silver, Black 5/93 production (euro)
94 M5 Touring Madeira Schwarz, Black 10/93 production
00 M5 Carbon Black, Black exclusive