Do you own a BMW, 1993-2006?
If so then your vanos engine variable valve timing unit, is most likely failing. These vanos units have been consistently diagnosed to fail due to deteriorating piston seal O-rings. The O-rings are made of rubber that is drying out in the engine's environment. This causes the vanos piston seals to lose their sealing function and for the vanos unit to fail. BMW does not provide the vanos seals separately. It sells rebuilt vanos units for ~$1500 installed. New rebuilt vanos units are supplied with the same failing rubber O-rings and have been found to fail in as little as 20k miles (32k kilometers) of use.
Vanos seal extended life is here!. Cerma Vanos Treatment will revitalize the O-rings and provide an easy to apply fix. No need to be without your car while mechanic replaces vanos unit, just pour in oil and drive. So easy, even a novice can do it. Cerma Vanos Treatment is a "one-time" treatment, no need for additional product for the life of the unit.
Within 100-500 miles you will notice improved performance, no rattle start ups, more power, overall performance gains.
Vanos Seals Failure Symptoms:
The first sign of a failing Vanos unit is rattling at start up of the engine, more advanced signs are knocking sound from idle to 2000 rpms, leading to a surging feeling around 1800-2000 rpm. Overall loss of torque and power, particularly in the lower RPM range, < 2k. Bogging then surging at 2k RPM. Uneven power distribution and RPM transition. Engine hesitations in the lower RPM range, < 3k. Louder idle and intermittent idle RPM hiccups. Difficult takeoffs. Loss of power and bogging when AC on. Increased fuel consumption. Vanos fault codes. Double vanos cars with the M52TU engine (98/99-00) experience cold weather cold start idle jolts and possible stall.
Cerma Vanos Treatment Benefits:
Overall increase in torque and power, particularly in the lower RPM range, < 2k. Resolution of bogging then surging at 2k RPM. Smooth even distribution of power and RPM transition. Resolution of engine hesitations in the lower RPM range, < 2k. Quiet stable idle. Smooth easy takeoffs. Improved performance when AC on. Reduced fuel consumption. Resolution of vanos fault codes. Resolution of double vanos M52TU engine (98/99-00) cold weather cold start idle jolts and possible stall.