smiddy 76 Report post Posted July 27, 2010 (edited) Just ordered dual vanos teflon seal replacement upgrade kit for my E46 cold start idle surges from Beisan Systems. Any of you guys with M52/54 engines have cold idle or low RPM bog issues? Stock vanos seals degrade due heat and synthetic oils allowing oil to bypass vanos pistons, especially sprung loaded exhaust vanos effecting torque and linear power curve. Said to be a problem after 20,000 mls. Edited July 27, 2010 by wayney Quote Share this post Link to post Share on other sites