Join the community and post your question. Use our Ask-A-Tech for free now! ASE experts standing by.

Forum > General Smog Check > Question

1989 BMW 325i Smog Check Dynomometer Testing RPM Speed

Past smog testing recorded for my 1989 BMW 325i at 15/25 mph had the RPMs of 1700/1800 range. This time they’re in 2300/2600 range. Why? Is the objective to achieve “speed” or an RPM level? If RPM level is required, where in state documents are these levels specified? I can’t seem to find anything about required RPM levels needing to be achieved during dyno testing.

Answer:

The required RPMs are set by the State of California, and the information is downloaded to the smog check machine. The smog check process requires a technician to drive a vehicle in 2nd gear (for standard transmissions) and obtain the correct RPMs in order to complete the smog check. The "correct" RPMs will be displayed in a window on the smog machine while the smog test is being administered. The technician will need to keep the RPM marker within this window during the dynamometer portion of the smog test. posted by SmogTips Support

Related questions and answers you might find useful:

How Do I Get a Smog Check Waiver? by Margaret

Do I Need a Smog Check This Year? by Joy

Mini Cooper DMV Registration Due in 5 Day Won't Pass Smog by anne

2001 Jeep Grand Cherokee Laredo with K&N Air Filter by David

1995 BMW M3 Gross Polluter High HC & NO @ 15MPH by Jared

View SmogTips.com in: Desktop / Mobile